Identification of novel anti-cancer agents by the synthesis and cellular screening of a noscapine-based library
Faezeh Nemati a, 1, Iris Bischoff-Kont b, 1, Peyman Salehi a,*, Samad Nejad-Ebrahimi a,
Maryam Mohebbi a, Morteza Bararjanian a, Nasim Hadian a, Zahra Hassanpour a, Yvonne Jung b, Sofie Schaerlaekens c, Daniel Lucena-Agell c, María A. Oliva c, Robert Fürst b, Hamid R. Nasiri d,*
a Department of Phytochemistry, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran, Iran
b Institute of Pharmaceutical Biology, Goethe University, 60438 Frankfurt am Main, Germany
c Centro de Investigaciones Biol´ogicas Margarita Salas (CSIC), Ramiro de Maeztu, 9, 28040 Madrid, Spain
d Department of Cellular Microbiology, University Hohenheim, 70599 Stuttgart, Germany
A R T I C L E I N F O
Keywords: Noscapine Papaver
Huisgen reaction Anticancer agents Drug repurposing Natural product Tubulin-binding
A B S T R A C T
Noscapine is a natural product first isolated from the opium poppy (Papaver somniferum L.) with anticancer properties. In this work, we report the synthesis and cellular screening of a noscapine-based library. A library of novel noscapine derivatives was synthesized with modifications in the isoquinoline and phthalide scaffolds. The so generated library, consisting of fifty-seven derivatives of the natural product noscapine, was tested against
MDA-MB-231 breast cancer cells in a cellular proliferation assay (with a Z’ > 0.7). The screening resulted in the
identification of two novel noscapine derivatives as inhibitors of MDA cell growth with IC50 values of 5 µM and
1.5 µM, respectively. Both hit molecules have a five-fold and seventeen-fold higher potency, compared with that of lead compound noscapine (IC50 26 µM). The identified active derivatives retain the tubulin-binding ability of noscapine. Further testing of both hit molecules, alongside the natural product against additional cancer cell lines (HepG2, HeLa and PC3 cells) confirmed our initial findings. Both molecules have improved anti- proliferative properties when compared to the initial natural product, noscapine.
1. Introduction
Noscapine is an alkaloid first isolated from Papaver somniferum. As a drug, it has been approved by the Food and Drug Administration (FDA) as a cough suppressant. According to the Biopharmaceutical Classifica- tion System (BCS), noscapine is a class IV Active Pharmaceutical Ingredient (API). The natural product-based drug has proper clinical safety and excellent preclinical pharmacokinetics and bioavailability [1]. As reported by Ye et al. in 1998, noscapine also has anticancer ac- tivities by arresting the cells at mitosis [2]. The mode of action as identified by us and others is the direct binding of noscapine and its derivatives to microtubules [3,4]. Additionally, we have recently shown that noscapine and noscapine-derived compounds also act as anti- protozoal agents [5] and inhibit insulin fibrillation [6].
Breast cancer is the most common in women worldwide and in the U. S., it is the cause of more than 42,000 deaths per year [7]. Anticancer
agents from natural origins, such as eribulin, taxol and vinblastine, that target the microtubules show significant success in the treatment of patients. However, the side effects of existing treatments justify the search for new scaffolds with lower toXicity and higher efficacy. In light of the excellent pharmaceutical properties of noscapine-based com- pounds, repurposing it as an anticancer drug is the scope of current research [8].
The chemical structure of noscapine consists of isoquinoline and a phthalide moiety. Many studies in the literature report the chemical modification of the noscapine scaffold, including the methyl-residue of the isoquinoline moiety [9,10], modification of the phthalide moiety [11], and of both parts [12,13]. Noscapine derivatives with modifica- tions at positions 1, 6, 7 and 9 were reported (Fig. 1) [14]. More recent studies have revealed that the introduction of halogens at the 9-position results in improved anticancer activity [1,15].
The copper-catalyzed cycloaddition reaction between alkynes and
* Corresponding authors.
E-mail addresses: [email protected] (P. Salehi), [email protected] (H.R. Nasiri).
1 These authors contributed equally.
https://doi.org/10.1016/j.bioorg.2021.105135
Received 28 February 2021; Received in revised form 26 June 2021; Accepted 27 June 2021
Available online 30 June 2021
0045-2068/© 2021 Elsevier Inc. All rights reserved.
Fig. 1. Sites of modification on the noscapine molecule.
azides, the CuAAC, also known as the Huisgen reaction, forms the 1,4- disubstituted 1,2,3-triazole ring, which is a Bioisostere of an amide bond [16] with excellent stability against metabolic degradation [17].
In the current study, we describe the synthesis of four series of noscapine derivatives, namely i) the N-nornoscapine, ii) the brominated N-nornoscapine, iii) the reduced form of N-nornoscapine and iv) the reduced form of the brominataed N-nornoscapine. CuAAC was used as the key reaction for the synthesis of the noscapine-based library. High yield, inoffensive byproduct, easy purification procedure and its ability
to carry out in biological condition make it an attractive reaction to use [17].
Following the chemical approach described above, a novel noscapine-based library of 57 compounds was generated. A proliferation assay was performed to triage the most potent noscapine derivatives.
2. Results and discussion
2.1. Chemical synthesis
Our strategy for the synthesis of target molecules is depicted in Scheme 1. Noscapine (1) was the parent molecule and starting point for the synthesis of all designed compounds (4–8). By N-demethylation of 1, in the presence of hydrogen peroXide and ferrous sulfate, N-nornosca- pine (2) was prepared. Direct propargylation of nitrogen by propargyl bromide followed by Huisgen 1,3-dipolar cycloaddition in the presence of CuSO4 and sodium ascorbate ended up with the formation of 4. The same structure (6) with the reduced lactone ring was synthesized by pretreatment of 2 with NaBH4 and BF3.Et2O followed by the routine construction of 1,2,3-triazole ring. Due to the reported increased bio- logical activities of 9-bromo-noscapine derivatives [15], also bromo- derivatives 4 and 6 were synthesized. For prior bromination, com- pound 5, was prepared by the reaction of HBr/Br2 with N-nornoscapine
(2) and the 9-brominated product was subjected to N-propargylation and consequent construction of 1,2,3-triazole ring. The 9-bromo de- rivatives of 6 with a reduced lactone ring (7) were synthesized starting from 3 by consecutive bromination, propargylation and Huisgen 1,3- dipolar cycloaddition. Finally, to investigate the activity of lactone ring-opened products, compound 8 was synthesized by prior N-alkyl- ation of N-nornoscapine (2) followed by reduction of the lactone ring with LiAlH4 to the corresponding diol and final t-butyl dimethyl silyla- tion of the primary hydroXyl group.
As depicted in Scheme 1, for the synthesis of all 1,2,3-triazoles (4–7),
Scheme 1. Synthesis of the noscapine-based library.
N-propargylated compounds were used as precursors of Huisgen reac- tion. The structure of these compounds (4′- 7′) is shown in Fig. 2.
Different types of azides were used to identify the influence of
Table 1
Noscapine-based chemical library synthesized following the chemical routes presented in Scheme 1.
structures and functional groups on cancer cell proliferation. Thus, benzylic azides were synthesized as one class of compounds. Aryl azides with electron-donating and electron-withdrawing groups were the other class, used as 1,3-dipole to synthesize triazoles. Finally, some aliphatic azides bearing hydroXyl groups were utilized as the third class of com- pounds (Table 1).
2.2. Physiochemical characterization of the noscapine-based library
The drug-like properties and violation of the Lipinski rule for all compounds were evaluated through ADMET prediction using the Qik- prop4.4 software (Table S1). Based on the Lipinski rule, it has been
suggested that the molecular weight (MW < 500), H acceptor bonds (HA < 10), H donor bonds (HD < 5), and octanol/water partition co- efficient (QPlogPo/w 2–6.5). Most of the synthesized compounds
showed good matching with these rules and proper human oral ab- sorption capacity (Table S1).
2.3. Screening of noscapine-based library against MDA-MB-231, HepG2, HeLa and PC3 cancer cell lines
All cancer cell types were seeded in a low density and cultivated for 24 h before they were treated with the respective compound for 72 h. Subsequently, the cells were stained with a crystal violet solution. Using acetic acid, DNA-bound crystal violet was solved from the cells, and absorption was measured at 590 nm. MDA-MB-231 cells were initially
treated with 10 µM of each compound (Fig. 3). Subsequently, com-
pounds showing a higher activity than 2/3 of noscapine-induced inhi- bition of MDA-MB-231 cell proliferation were taken further and tested at a lower top concentration of 1 µM (Fig. 3). The proliferation values for the noscapine derivatives, tested at 10 µM and 1 µM, were summarized in the supplementary material (Table S2). Following this hit triage strategy, compounds 6a and 6′ were identified and selected for an IC50
Entry Compound Substituent Reaction Time
Yield (%)
determination in MDA-MB-231 cells (Fig. 4).
The identified hit compounds 6a and 6′ were further tested in a concentration–response experiment against the MDA-MB-231 cell line after 24 h, 48 h (see supplementary material) and 72 h incubation. For this experiment, both molecules were re-synthesized on a large scale. Freshly prepared material was used in order to exclude any potential false positives arising from degradation or byproducts of the hit mole- cules dissolved in DMSO and stored in the screening plates. As a result, both hit molecules 6′ and 6a inhibit the growth of MDA-MB-231 cells in a concentration-dependent manner. 6′ revealed an IC50 value of 1.5 µM and 6a revealed an IC50 value of 5 µM. In addition, both compounds
Fig. 2. Structures of N-propargylated compounds used as precursors of Huis- gen reaction.
56 6′ – 2 h 80
57 7′ – 2 h 85
showed lower IC50 values compared to noscapine (IC50: 26 µM); see Fig. 4.
Looking at the structure and the observed activity, by comparing the noscapine (1) and hit molecule 6′, one can recognize that there are two modifications, namely i) the keto group in phthalide moiety at 1-posi- tion is removed and ii) an alkyne has been introduced at the 6-position
Fig. 3. Testing of the noscapine-based library at 10 and 1 µM in replicates (n = 3–4). Negative control ctrl = DMSO, highlighted in black; positive control = doXorubicin (300 nM), highlighted in red: control compound = noscapine 10 µM (left) and 1 µM (right), highlighted in green. Active compounds 6a and 6′ are highlighted in blue. All compounds showing a higher activity than 2/3 of noscapine-induced inhibition of MDA-MB-231 cell proliferation activity (dashed line) were selected as primary active compounds and were used for further experiments.
Fig. 4. Testing identified hit compounds 6a and 6′ in a concentration–response experiment against MDA-MB-231 cell line after 72 h incubation. 6′ IC50: 1.5 µM, 6a IC50: 5 µM. DoXorubicin served as control. DoXorubicin IC50: 0.57 µM, noscapine IC50: 26 µM. Z-score: 0.75. Data are expressed as mean ± SEM (n
= 4).
of the isoquinoline moiety (see Fig. 5). Interestingly, just introducing the alkyne at the 6-position of the isoquinoline moiety of noscapine would not improve activity. On the contrary, compound 4′ turned out to be inactive. Again, the observed activity of the other identified hit molecule 6a, confirms that removing the keto group in phthalide moiety at 1-po- sition is an excellent strategy to improve the anticancer activity of noscapine.
Several studies have been implemented about noscapinoids’ anti-
proliferative activities against MDA-MB-231 cells. Lopus et al. have re-
In another study, a number of brominated analogues such as 9- bromo-7-O-acetyl and 9-bromo-7-O-(N-substituted acetamide) de- rivatives of noscapine have been synthesized showing anti-proliferative activities in the IC50 range of 2.5–20 μM [20].
Encouraged by the positive outcome of the cellular testing, the hit molecules 6′ and 6a were further investigated by analyzing their anti- proliferative activity against additional cancer cell lines: HepG2 (liver cancer), HeLa (cerviX carcinoma) and PC3 (prostate cancer) (Fig. 6).
IC50: HepG2 6′: 0.5 µM, 6a: 2.3 µM, doxorubicin: 0.08 µM, nosca-
pine: 14 µM; HeLa 6′: 0.63 µM, 6a: 1.4 µM, doxorubicin: 0.1 µM,
noscapine: 10 µM; PC3 6′: 0.6 µM, 6a: 1.2 µM, doxorubicin: 0.08 µM, noscapine: 24 µM. DoXorubicin served as control. Data are expressed as mean ± SEM (HepG2 (n = 4–6), HeLa (n = 3), PC3 (n = 3–5)).
2.4. Target engagement
To validate tubulin as the molecular target of compounds 6′ and 6a, we have employed a tubulin assembly inhibition assay. This study uses purified tubulin in a buffer in which the protein is able to assembly into microtubules even in the absence of microtubule-associated protein. Therefore, any effect within tubulin assembly will be the consequence of the direct interaction of these compounds. We monitor tubulin assembly also in the presence of podophyllotoXin as control, because it is a known colchicine site binder that blocks tubulin curved-to-straight conforma- tional change upon assembly and hence, inhibits tubulin assembly. As
ported the synthesis of 9-(4-vinylphenyl) noscapine which was found to
expected, podophyllotoXin inhibits tubulin assembly at sub-
have promising activity with IC50 of 6 μM [18,19].
stoichiometric concentrations (Fig. 7, top). We found that at the lowest drug concentration tested (1 µM) there is a clear effect on tubulin
Fig. 5. Structure-activity relationship of noscapine-derived hits and inactive compounds.
Fig. 6. Testing of identified hit compounds 6a and 6′ in a concen- tration–response experiment against HepG2, HeLa and PC3 cell line after 72 h incubation.
nucleation directly affecting assembly. At 10 µM, we reached the highest inhibition rate of the drug (i.e. inhibition is similar to that found at higher podophyllotoXin concentrations).
Compound 6′ (Fig. 7, bottom) induced clear inhibition of the tubulin assembly at medium concentrations (10unM), implying that the effect found in cells is directly linked to this compound. As denoted from the polymerization assays, 6′ effect on tubulin assembly is lower than that of podophyllotoXin but still highly significant. However, compound 6a inhibition of tubulin assembly is very weak and only induces a minor effect on tubulin nucleation at stoichiometric concentrations (Fig. 7, middle), which also correlates with the lower cytotoXicity observed. This could be either due to the lower solubility of the compound, which prevents it from reaching the higher concentrations required to fully inhibit the tubulin assembly, or because of the presence of a minor active impurity.
3. Conclusion
In summary, the synthesis of 57 novel noscapine derivatives by using the Huisgen reaction is described. The so generated library was tested in a phenotypic screen against four cancer cell lines monitoring cell pro- liferation. As a result, two primary active compounds were identified, showing anti-proliferative activities in the low µM range against all four
Fig. 7. Polymerization curves of 25 µM tubulin (black line) in the presence of 0.5% DMSO (control of the solvent used with compound, gray line), 27.5 µM noscapine (orange line) and increasing concentrations (1, 2, 5, 10, 15, 20, 25 and 30 µM, blue lines from lighter to darkest colors) of podophyllotoXin (top), compound 6a (middle) and compound 6′ (bottom). Tubulin (black line).
cell lines. The hereby-identified compounds have higher anti- proliferative activities when compared to the lead molecule noscapine. Both compounds engage tubulin as the primary molecular target.
4. Experimental section
4.1. General
Medicinal grade Noscapine was donated by Faran Shimi Pharma- ceutical Co. Other chemicals and solvents were provided from Merck, Sigma-Aldrich, and Kimia EXir chemical companies without any further purification. Reactions progress was monitored on silica gel 60 F254 plates (Merck) and the spots were visualized under UV light. Silica gel 60
(particle size 0.063–0.200 μm, 70–230 mesh) was used for column
chromatography. Melting points were measured on an Electrothermal 9200 instrument and are uncorrected. Azides were synthesized accord- ing to the literature procedures [21].
FT-IR spectra were recorded on a Bruker Tensor 27 spectrometer. 1H NMR and 13C NMR spectra were obtained on Bruker 300 and 600 MHz
instruments. NMR spectra were run in CDCl3 as solvent and TMS was used as internal standard and chemical shifts are expressed in parts per million (ppm). Signal multiplicities are reported as: s singlet; d doublet; t triplet; dd doublets of doublets; m multiplet. Coupling constants (J) are reported in Hertz (Hz).
Compound 4′:
85% yield, yellow crystal, 1H NMR (600 MHz, CDCl3): δ = 6.90 (d, 1H, J = 8.2 Hz, HAr), 6.28 (s, 1H, HAr), 5.93 (d, 1H, J = 1.2 Hz, O-CH2-
O), 5.92 (d, 1H, J = 1.2 Hz, O-CH2-O), 5.52 (d, 1H, J = 4.0 Hz, CH-O),
4.79 (d, 1H, J = 4.0 Hz, CH-N), 4.05 (s, 3H, OMe), 4.04 (s, 3H, OMe),
3.87 (dd, 1H, J = 17.4, 2.2 Hz, CH2), 3.83 (s, 3H, OMe), 3.42 (dd, 1H, J
= 17.4, 2.2 Hz, CH2), 2.68 (td, 1H, J = 10.9, 3.0 Hz, CH2-N), 2.54–2.57
N-nornoscapine, (3S)-6,7-dimethoXy-3-((R)-4-methoXy-5,6,7,8-tet-
(m, 1H, CH2-N), 2.29 (dt, 1H, J = 15.4, 3.3 Hz, CH2), 2.08 (t, 1H, J = 2.3
rahydro-[1,3]dioXolo [4,5-g]isoquinolin-5-yl)isobenzofuran-1(3H)-one 2: noscapine (50 mmol, 20.6 g) was suspended in acetonitrile (300 mL) and H2O2 (300 mL) was added to the miXture. The reaction miXture was stirred at room temperature until the formation of a clear solution (about 4–6 h). EXcess of H2O2 was deactivated by MnO2 and the miXture was filtered on celite pad and acetonitrile was evaporated. The residue was acidified by 6 N HCl and extracted with CHCl3. The organic layer was washed with brine and dried over anhydrous sodium sulfate and concentrated in a vacuum to afford the N-oXide hydrochloride as a yellow solid (23.25 g). The crude product was dissolved in 2000 mL MeOH and stirred at 10◦ C. FeSO4⋅7H2O (75 mmol, 20.8 g) was added and stirring was continued overnight. MeOH was removed in a vacuum and residue was dissolved in acidic EDTA (2 eq) and extracted with CHCl3 (3 × 50 mL). The organic layers were combined and washed with
10% NaOH and brine, dried over anhydrous Na2SO4 and evaporated to yield a crude nornoscapine free base. The product was purified by vacuum liquid chromatography (VLC) using n-hexane/ EtOAc as eluent to give compound 2 (10 g, 50% yield) as a yellow solid.
1H NMR (600 MHz, CDCl3): δ = 6.91(d, 1H, J = 8.2 Hz, HAr), 6.30 (s,
1H, HAr), 5.95 (d, 1H, J = 8.2 Hz, HAr), 5.93 (d, 1H, J = 1.2 Hz, O-CH2-
O), 5.92 (d, 1H, J = 1.2 Hz, O-CH2-O), 5.89 (d, 1H, J = 3.8 Hz, CH-O),
4.83 (d, 1H, J = 3.8 Hz, CH-N), 4.06 (s, 3H, OMe), 4.02 (s, 3H, OMe),
3.81 (s, 3H, OMe), 2.61–2.64 (m, 1H, CH2-N), 2.43–2.48 (m, 1H, CH2-
N), 2.28–2.32 (m, 1H, CH2), 2.12–2.16 (m, 1H, CH2), 1.99 (bs, 1H, NH).
13C NMR (150 MHz, CDCl3): δ 198.5, 152.2, 148.4, 147.9, 141.1,
140.5, 134.2, 131.9, 119.6, 118.5, 117.6, 116.9, 103.1, 100.8, 80.6,
62.3, 59.5, 56.7, 52.8, 39.5, 29.6.
Reduced N-nornoscapine; (5R)-5-((1S)-4,5-dimethoXy-1,3-dihydro- 2-benzofuran-1-yl)-4-methoXy-5,6,7,8-tetrahydro[1,3]dioXolo[4,5-g] isoquinoline (3).
The reduction of N-nornoscapine lactone was carried out according to the previous report with some modifications [10]. N-nornoscapine (1.88 mmol, 0.75 g) and NaBH4 (5.8 mmol, 0.22 g) were dissolved in THF (18 mL). BF3.Et2O (18 mL) was added in this solution at 5 ◦C. After 1 h, the reaction was continued at room temperature and stirred
overnight. To quench the reaction, HCl (10 mL, 10% aq) was added dropwise in an ice bath. After 1 h, the reaction was extracted with CHCl3 (3 × 30 mL) and the organic layer was isolated and dried over anhydrous
Na2SO4. This compound was used for the next step without any further purification; Yield: 80%, cream powder, m.p. 95–98 ◦C; IR (KBr) (ν / cm—1) : 3500, 2940, 1610, 1485, 1377, 1261, 1220, 1080, 1030; 1H
NMR (300 MHz, CDCl3), (δ, ppm): 6.61 (d, 1H, J = 8.2 Hz, HAr), 6.35 (s,
1H, HAr), 5.95 (s, 2H, O-CH2O), 5.85 (d, 1H, J = 8.2 Hz, HAr), 5.77–5.81
(m, 1H, O-CH), 5.39 (dd,1H, J = 12.4, 2.8 Hz, O-CH2), 5.20 (d, 1H, J =
12.4 Hz, O-CH2), 4.64 (d, 1H, J = 4.00 Hz, N-CH), 4.01 (s, 3H, OMe),
3.87 (s, 3H, OMe), 3.82 (s, 3H, OMe), 2.53–2.72 (m,3H, N-CH2,CH2),
2.21–2.40 (m, 2H, CH2, NH).
Propargylated N-nornoscapine (4′):
N-nornoscapine (7.98 g, 20 mmol) was dissolved in 20 mL CH3CN and 8.30 g potassium carbonate (60 mmol, 3 eq) was added to the so- lution. In addition, 2.9 mL propargyl bromide (26 mmol, 1.3 eq) was dissolved in 5 mL CH3CN and added to the miXture. The reaction miXture was refluXed for 2 h and cooled to room temperature. The sol- vent was evaporated and the residue was dissolved in ethyl acetate and washed with brine. The organic layer was dried over sodium sulfate and concentrated to obtain the crude product. Further purification was made by flash column chromatography with n-hexane/ CH2Cl2 as eluent to give compound 4′ (7.9 g, 90% yield).
Hz, CHAcetylene), 1.76–1.81 (m, 1H, CH2). 13CNMR (150 MHz, CDCl3): δ
167.9, 152.2, 148.4, 147.5, 140.4, 140.3, 134.4, 132.5, 120.3, 118.1,
117.7, 117.3, 102.3, 100.9, 82.0, 80.1, 72.3, 62.3, 59.6, 57.2, 47.5, 46.7,
29.1.
Compound 5′:
Yield: 80%, yellow powder, m.p.: 175–177 ◦C, IR (KBr, cm—1): 3290, 2945, 2840, 1760, 1609, 1497, 1447, 1387, 1267, 1215, 1042, 907, 803,
730, 645, 1HNMR (600 MHz, CDCl3) δ (ppm): 1.91–2.02 (m, 1H),
2.42–2.49 (m, 2H), 2.57–2.67 (m, 2H), 2.74–2.83 (m, 1H), 2.93–3.01
(m, 1H), 3.87 (s, 3H), 3.99 (s, 3H), 4.08 (s, 3H), 4.27 (d, J 4.7 Hz, 1H),
5.39 (d, J 4.7 Hz, 1H), 6.02 (s, 2H), 6.26 (d, J 8.2 Hz, 1H), 6.96 (d, J
8.2 Hz, 1H), 13CNMR (150 MHz, CDCl3) δ (ppm): 27.3, 46.2, 46.6,
56.8, 57.5, 59.7, 62.3, 72.5, 79.9, 81.6, 95.51, 101.2, 117.6, 118.2,
119.3, 120.0, 131.1, 134.6, 139.8, 140.4, 146.6, 147.7, 152.4, 167.8, HRMS: [M + H]+ calcd = 516.0574, found = 516.0640.
Compound 6′:
85% yield, yellow crystal, IR (KBr, cm—1): 3435, 3259, 2913, 2102,
1622, 1485, 1378, 1268, 1211, 1037. 1H NMR (300 MHz, CDCl3), (δ, ppm): 6.63 (d, 1H, J = 8.2 Hz, HAr), 6.32 (s, 1H, HAr), 5.94 (s, 2H, O-
CH2O), 5.90 (d, 1H, J = 8.2 Hz, HAr), 5.34–5.42 (m, 1H, O-CH), 5.26 (dd,
1H, J = 12.0, 2.8 Hz, O-CH2), 5.11 (d, 1H, J = 12.0 Hz, O-CH2), 4.59 (d,
1H, J = 3.9 Hz, N-CH), 4.00 (s, 3H, OMe), 3.86 (dd, 1H, J = 16.9, 2.4 Hz,
CAcetylene-CH2), 3.87 (s, 3H, OMe), 3.61 (dd, 1H, J = 16.9, 2.4 Hz,
CAcetylene-CH2), 2.73–2.90 (m, 1H, N-CH2), 2.55–2.74 (m, 1H, N-CH2),
2.29–2.45 (m, 1H, CH2), 2.15 (m, 1H, CHAcetylene), 1.98–2.12 (m, 1H, CH2).
Compound 7′:
85% yield, white solid, m. p. : 59–62 ◦C; IR(KBr, cm—1): 3292, 3050,
2907, 2800, 1613, 1490, 1445, 1037; 1H NMR (300 MHz, CDCl3), (δ, ppm): 6.68 (d, 1H, J = 8.1 Hz, HAr), 6.08 (d, 1H, J = 8.1 Hz, HAr), 6.02 (s,
2H, O-CH2 -O), 5.32 (br s, 1H, CH-O), 5.19 (d, 1H, J = 12.5 Hz, CH2 -O),
5.09 (d, 1H, J = 12.5 Hz, CH2 -O), 4.56 (d, 1H, J = 3.9 Hz, CH-N), 3.93
(s, 3H, OMe), 3.86 (s, 6H, 2OMe), 3.77 (d, 1H, J = 16.9 Hz, CH2 -CAce- tylene), 3.54 (d, 1H, J = 16.9 Hz, CH2 -C Acetylene), 2.96–2.86 (m, 1H, CH2), 2.78–2.63 (m, 2H, CH2), 2.17 (s, 1H, CH Acetylene), 2.08–1.94 (m, 1H, CH2).
4.1.1. General procedure for the formation of triazole derivatives 4a-m, 5a-f, 6a-r, 7a-j
Propargylated intermediate (4′, 5′, 6′ or 7′) (0.15 mmol) was dis- solved in 1 mL of methanol: dichloromethane: water (1: 1: 1). Then 10 mol% of CuSO4⋅5H2O (0.015 mmol, 0.0037 g) and 20 mol% of sodium ascorbate (0.03 mmol, 0.006 g) were added to the flask. The reaction miXture was stirred at room temperature for 10 min until complete consumption of the porpagylated intermediate which was confirmed by TLC (toluene: ethyl acetate, 2:1). Ammonia solution (25%) was added and the crude product was extracted with CH2Cl2 (3 10 mL). Finally, 1,2,3-triazole derivatives were purified by preparative thin-layer chro- matography (toluene: ethyl acetate, 3:1).
The experimental procedures for the synthesis of compounds 6b, 6c, 6d, 6j, 6l, 6m, 6n, 6p, 6r and 7c, 7d, 7e, 7h, 7i, have been recently reported. [4]
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(4-nitrophenyl)-1H-
1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]iso- quinolin-5-yl)isobenzofuran-1(3H)-one 4a:
Yield: 96%, pale-yellow solid, mp 150–151 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 8.48 (s, 1H, HTriazole), 8.40 (d, 2H, J = 9.0 Hz, HAr), 8.16 (d,
2H, J = 9.0 Hz, HAr), 6.92 (d, 1H, J = 8.2 Hz, HAr), 6.31 (s, 1H, HAr), 5.99
(d, 1H, J = 8.2 Hz, HAr), 5.94 (s, 1H, O-CH2-O), 5.92 (s, 1H, O-CH2-O),
5.76 (d, 1H, J = 3.9 Hz, CH-O), 4.51 (d, 1H, J = 3.9 Hz, CH-N), 4.15 (d,
1H, J = 14.1 Hz, CH2), 4.06 (s, 3H, OMe), 4.05 (s, 3H, OMe), 3.82 (s, 3H,
OMe), 3.81 (d, 1H, J = 14.3 Hz, CH2), 2.46–2.51 (m, 1H, CH2N),
2.35–2.39 (m, 1H, CH2N), 2.10–2.14 (m, 1H, CH2), 1.82–1.86 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 169.2, 152.5, 148.7, 148.3,
147.8, 146.9, 141.5, 140.5, 140.4, 134.1, 131.5, 125.5, 122.1, 120.3,
120.1, 118.2, 117.9, 115.6, 102.6, 100.8, 80.7, 62.2, 59.5, 58.7, 56.6,
52.8, 46.5, 25.7, HRMS (ESI): [M H]+ calculated for C30H28N5O9,
602.1887; found, 602.1938.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(4-flourophenyl)-1H-
1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]iso-
1H, J = 2.8 Hz, CH-N), 4.16 (d, 1H, J = 14.0 Hz, CH2), 4.04 (s, 6H, 2
OMe), 3.86 (d, 1H, J = 14.0 Hz, CH2), 3.82 (s, 3H, OMe), 2.45–2.47 (m,
1H, CH2N), 2.38–2.39 (m, 1H, CH2N), 2.27–2.29 (m, 1H, CH2),
1.81–1.83 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.8, 152.2,
149.3, 148.1, 146.9, 140.6, 140.5, 137.3, 134.1, 131.8, 130.9, 129.6,
128.3, 121.7, 120.2, 120.1, 118.1, 117.9, 102.6, 100.8, 80.9, 62.3, 59.5,
58.8, 56.7, 52.8, 46.4, 26.3, HRMS (ESI): [M + H]+ calculated for
C30H29N4O7, 557.2036; found, 557.2094.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(pyridin-3-yl)-1H-
1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]iso- quinolin-5-yl)isobenzofuran-1(3H)-one 4f:
Yield: 92%, pale-yellow solid, mp 150–151 ◦C. 1H NMR (600 MHz,
quinolin-5-yl)isobenzofuran-1(3H)-one 4b:
Yield: 92%, pale-yellow solid, mp 100–102 ◦C.
1H NMR (600 MHz,
CDCl3): δ = 9.18 (d, 1H, J = 2.4 Hz, Hortho), 8.65 (dd, 1H, J = 4.8, 1.3 Hz,
Hortho), 8.35 (s, 1H, HTriazole), 8.21 (ddd, 1H, J = 8.2, 2.4, 1.3 Hz, Hpara),
CDCl3): δ = 8.24 (s, 1H, HTriazole), 7.84–7.86 (m, 2H, HAr), 7.19 (t, 2H, J
= 8.5 Hz, HAr), 6.91 (d, 1H, J = 8.2 Hz, HAr), 6.30 (s, 1H, HAr), 5.99 (d,
1H, J = 8.2 Hz, HAr), 5.93 (s, 1H, O-CH2-O), 5.92 (s, 1H, O-CH2-O), 5.72
(d, 1H, J = 3.9 Hz, CH-O), 4.55 (d, 1H, J = 3.9 Hz, CH-N), 4.14 (d, 1H, J
= 14.1 Hz, CH2), 4.04 (s, 3H, OMe), 4.03 (s, 3H, OMe), 3.83 (d, 1H, J =
14.1 Hz, CH2), 3.81 (s, 3H, OMe), 2.44–2.49 (m, 1H, CH2N), 2.35–2.39
(m, 1H, CH2N), 2.19–2.23 (m, 1H, CH2), 1.79–1.84 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.9, 163.0, 161.3, 152.3, 148.5, 147.7,
147.2, 140.5, 134.1, 133.6, 133.6, 131.7, 122.1, 122.1, 121.9, 120.1,
118.1, 117.9, 116.6, 116.4, 116.1, 102.6, 100.8, 80.8, 62.2, 59.5, 58.7,
56.4, 52.8, 46.4, 26.0, HRMS (ESI): [M + H]+ calculated for
C30H28FN4O7, 575.1942; found, 575.2003.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(4-methylbenzyl)-1H-
1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]iso- quinolin-5-yl)isobenzofuran-1(3H)-one 4c:
Yield: 95%, pale-yellow solid, mp 80–82 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 7.62 (s, 1H, HTriazole), 7.16 (d, 2H, J = 8.0 Hz, HAr), 7.13 (d,
2H, J = 8.0 Hz, HAr), 6.88 (d, 1H, J = 8.2 Hz, HAr), 6.27 (s, 1H, HAr), 5.98
(d, 1H, 8.2 Hz, HAr), 5.91 (s, 1H, O-CH2-O), 5.90 (s, 1H, O-CH2-O), 5.62
(d, 1H, J = 4.1 Hz, CH-O), 5.42 (ABq, 2H, J = 14.7 Hz, CH2), 4.55 (d, 1H,
J = 4.1 Hz, CH-N), 4.04 (d, 1H, J = 13.8 Hz, CH2), 3.99 (s, 3H, OMe),
3.95 (s, 3H, OMe), 3.82 (d, 1H, J = 13.8 Hz, CH2), 3.81 (s, 3H, OMe),
2.36–2.41 (m, 2H, CH2N), 2.31–2.33 (m, 2H, 2 CH2), 2.33 (s, 3H, Me),
1.73–1.78 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.5, 152.2,
148.4, 147.6, 146.2, 140.6, 140.4, 138.2, 134.0, 132.1, 131.9, 129.6,
128.0, 123.3, 120.0, 118.0, 117.8, 116.6, 102.5, 100.7, 81.1, 62.2, 59.4,
58.8, 56.6, 52.7, 46.1, 26.7, 21.1. HRMS (ESI): [M + H]+ calculated for
C32H33N4O7, 585.2349; found, 585.2418.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(p-tolyl)-1H-1,2,3-tri- azol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-
yl)isobenzofuran-1(3H)-one 4d:
Yield: 90%, off white solid, mp 100–103 ◦C. 1H NMR (600 MHz, CDCl3): δ = 8.20 (s, 1H, HTriazole), 7.71 (d, 1H, J = 8.3 Hz, HAr), 7.29 (d,
1H, J = 8.1 Hz, HAr), 6.91 (d, 1H, J = 8.3 Hz, HAr), 6.29 (s, 1H, HAr), 5.99
(d, 1H, J = 8.1 Hz, HAr), 5.93 (s, 1H, O-CH2-O), 5.91 (s, 1H, O-CH2-O),
5.71 (d, 1H, J = 3.9 Hz, CH-O), 4.59 (d, 1H, J = 3.9 Hz, CH-N), 4.15 (d,
1H, J = 13.9 Hz, CH2), 4.04 (s, 3H, OMe), 4.03 (s, 3H, OMe), 3.86 (d, 1H,
J = 13.9 Hz, CH2), 3.81 (s, 3H, OMe), 2.42–2.47 (m, 1H, CH2N),
2.36–2.40 (m, 1H, CH2N), 2.39 (s, 3H, CH3), 2.27–2.31 (m, 1H, CH2),
1.79–1.83 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.8, 152.3,
148.5, 147.7, 146.8, 140.6, 140.5, 138.3, 135.0, 134.1, 131.9, 130.1,
121.6, 120.1, 118.1, 117.9, 116.4, 102.5, 100.8, 81.0, 62.3, 59.5, 58.8,
56.7, 52.9, 46.4, 26.4, 21.1, HRMS (ESI): [M + H]+ calculated for
C31H31N4O7, 571.2193; found, 571.2254.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-phenyl-1H-1,2,3-tri- azol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-
yl)isobenzofuran-1(3H)-one 4e:
Yield: 85%, pale-yellow solid, mp 90–91 ◦C. 1H NMR (600 MHz, CDCl3): δ = 8.28 (s, 1H, HTriazole), 7.85 (d, 2H, J = 7.9 Hz, HAr), 7.50 (t,
2H, J = 7.8 Hz, HAr), 7.38 (t, 1H, J = 7.5 Hz, HAr), 6.91 (d, 1H, J = 8.2
Hz, HAr), 6.30 (s, 1H, HAr), 6.01 (d, 1H, J = 8.2 Hz, HAr), 5.93 (s, 1H, O-
CH2-O), 5.92 (s, 1H, O-CH2-O), 5.72 (d, 1H, J = 2.8 Hz, CH-O), 4.58 (d,
7.47 (ddd, 1H, J = 8.2, 4.8, 0.5 Hz, Hmeta), 6.91 (d, 1H, J = 8.2 Hz, HAr),
6.3 (s, 1H, HAr), 6.01 (d, 1H, J = 8.2 Hz, HAr), 5.93 (d, 1H, J = 1.4 Hz, O-
CH2-O), 5.92 (d, 1H, J = 1.4 Hz, O-CH2-O), 5.73 (br s, 1H, CH-O), 4.56
(br s, 1H, CH-N), 4.18 (d, 1H, J = 14.0 Hz, CH2), 4.05 (s, 6H, 2 OMe),
3.86 (d, 1H, J = 14.0 Hz, CH2), 3.82 (s, 3H, OMe), 2.45–2.48 (m, 1H,
CH2N), 2.37–2.39 (m, 1H, CH2N), 2.22–2.25 (m, 1H, CH2), 1.82–1.84 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.9, 152.4, 149.5,
148.6, 147.7, 147.6, 141.7, 140.5, 140.4, 134.1, 133.8, 131.7, 127.6,
124.1, 121.9, 120.1, 118.1, 117.9, 116.0, 102.5, 100.8, 80.8, 62.2, 59.5,
58.8, 56.6, 52.8, 46.4, 26.1, HRMS (ESI): [M + H]+ calculated for
C29H28N5O7, 558.1989; found, 558.2046.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(benzyl)-1H-1,2,3-tri-
azol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5- yl)isobenzofuran-1(3H)-one 4g:
Yield: 97%, pale-yellow solid, mp 99–100 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 7.65 (s, 1H, HTriazole), 7.30–7.34 (m, 3H, HAr), 7.25 (d, 2H, J
= 6.9 Hz, HAr), 6.88 (d, 1H, J = 8.2 Hz, HAr), 6.27 (s, 1H, HAr), 5.98 (d,
1H, J = 8.2 Hz, HAr), 5.92 (S, 1H, O-CH2-O), 5.90 (s, 1H, O-CH2-O), 5.62
(d, 1H, J = 4.1 Hz, CH-O), 5.47 (ABq, 2H, J = 14.82 Hz, CH2), 4.54 (d,
1H, J = 4.1 Hz, CH-N), 4.05 (d, 1H, J = 13.7 Hz, CH2), 4.00 (s, 3H, OMe),
3.94 (s, 3H, OMe), 3.82 (d, 1H, J = 13.7 Hz, CH2), 3.81 (s, 3H, OMe),
2.36–2.40 (m, 1H, CH2N), 2.31–2.33 (m, 2H, CH2N, CH2), 1.75–1.77 (m,
1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.5, 152.2, 148.4, 147.6,
146.3, 140.6, 140.4, 134.9, 134.0, 132.1, 128.9, 128.4, 127.9, 123.4,
120.1, 118.0, 117.9, 116.6, 102.5, 100.8, 81.1, 62.2, 59.5, 58.8, 56.7,
54.0, 52.8, 46.2, 26.7, HRMS (ESI): [M + H]+ calculated for
C31H31N4O7, 571.2193; found, 571.2255.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(2-hydroXy-2-methyl-
propyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo [4,5-g]isoquinolin-5-yl)isobenzofuran-1(3H)-one 4h:
Yield: 95%, pale-yellow solid, mp 90–91 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 7.80 (s, 1H, HTriazole), 6.90 (d, 1H, J = 8.2 Hz, HAr), 6.29 (s,
1H, HAr), 6.01–6.02 (m, 1H, HAr), 5.93 (s, 1H, O-CH2-O), 5.91 (s, 1H, O-
CH2-O), 5.67 (d, 1H, J = 3.9 Hz, CH-O), 4.54 (d, 1H, J = 3.9 Hz, CH-N),
4.36 (d, 1H, J = 13.8 Hz, CH2), 4.26 (d, 1H, J = 13.8 Hz, CH2), 4.05 (d,
1H, J = 13.9 Hz, CH2), 4.03 (s, 3H, OMe), 4.01 (s, 3H, OMe), 3.81 (s, 3H,
OMe), 3.76 (d, 1H, J = 13.9 Hz, CH2), 2.44–2.49 (m, 1H, CH2N),
2.37–2.40 (m, 1H, CH2N), 2.27 (m, 1H, CH2), 1.82–1.85 (m, 1H, CH2),
1.24 (s, 3H, CH3), 1.19 (s, 3H, CH3). 13C NMR (150 MHz, CDCl3): δ
168.9, 152.3, 148.5, 147.6, 145.9, 140.5, 134.1, 131.7, 124.6, 120.0,
118.1, 117.9, 116.3, 102.6, 100.8, 80.9, 70.3, 62.2, 60.8, 59.5, 58.2,
56.6, 52.6, 46.6, 27.1, 26.4, 26.0, HRMS (ESI): [M + H]+ calculated for
C28H33N4O8, 553.2298; found, 553.2386.
(3S)-3-((R)-6-((1-(4-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)-4-
methoXy-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-yl)-6,7- dimethoXyisobenzofuran-1(3H)-one 4i:
Yield: 97%, pale-yellow solid, mp 79–81 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 7.69 (s, 1H, HTriazole), 7.27–7.29 (m, 2H, HAr), 7.01–7.04 (m,
2H, HAr), 6.90 (d, 1H, J = 7.0 Hz, HAr), 6.28 (s, 1H, HAr), 5.98 (br s, 1H,
HAr), 5.92 (s, 1H, O-CH2-O), 5.91(s, 1H, O-CH2-O), 5.65 (br s, 1H, CH-
O), 5.45 (s, 2H, CH2), 4.55 (br s, 1H, CH-N), 4.07 (d, 3H, J = 13.7 Hz,
CH2), 4.00 (s, 3H, OMe), 3.97 (s, 3H, OMe), 3.84 (d, 1H, J = 13.7 Hz,
CH2), 3.82 (s, 3H, OMe), 2.36–2.40 (br s, 1H, CH2N), 2.32 (br s, 2H, CH2N, CH2), 1.78 (br s, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ
168.6, 163.5, 161.9, 152.3, 148.5, 147.6, 146.5, 140.5, 140.4, 134.0,
130.8, 130.0, 129.9, 123.5, 120.0, 118.0, 117.9, 116.4, 116.0, 115.8,
102.5, 100.8, 81.1, 62.2, 59.5, 58.9, 56.7, 43.3, 52.8, 46.2, 26.6, HRMS
(ESI): [M H]+ calculated for C32H29FN4O7, 589.2099; found, 589.2170.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(4-methoXyphenyl)-1H-
1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]iso- quinolin-5-yl)isobenzofuran-1(3H)-one 4j:
Yield: 94%, pale-yellow solid, mp 85–88 ◦C. 1H NMR (600 MHz,
CDCl3): δ = 8.17 (s, 1H, HTriazole), 7.74 (d, 2H, J = 8.9 Hz, HAr), 6.99 (d,
2H, J = 8.9 Hz, HAr), 6.91 (d, 1H, J = 8.2 Hz, HAr), 6.30 (s, 1H, HAr), 6.01
(d, 1H, J = 8.2 Hz, HAr), 5.93 (s, 1H, O-CH2-O), 5.91 (s, 1H, O-CH2-O),
5.71 (d, 1H, J = 3.8 Hz, CH-O), 4.57 (d, 1H, J = 3.7 Hz, CH-N), 4.14 (d,
1H, J = 13.9 Hz, CH2), 4.04 (s, 3H, OMe), 4.03 (s, 3H, OMe), 3.85 (d, 1H,
J = 13.9 Hz, CH2), 3.84 (s, 3H, OMe), 3.81 (s, 3H, OMe), 2.43–2.47 (m,
1H, CH2N), 2.37–2.40 (m, 1H, CH2N), 2.27–2.29 (m, 1H, CH2),
1.80–1.83 (m, 1H, CH2). 13C NMR (150 MHz, CDCl3): δ 168.8, 159.4,
152.3, 148.5, 147.7, 146.7, 140.6, 140.5, 134.1, 131.8, 130.8, 121.8,
120.1, 118.1, 117.9, 116.3, 114.6, 102.5, 100.8, 80.9, 62.2, 59.5, 58.7,
CH-O, minor isomer), 4.57 (d, 1H, J = 4.02 Hz, CH-N, major isomer), 4.49–4.57 (m, 2H, CH2-CHOH, miXture of two isomers), 4.46 (d, 1H, J =
4.02 Hz, CH-N, minor isomer), 4.16–4.21 (m, 2H, CH2-CHOH, miXture of two isomers), 4.03–4.05 (m, 2H, CH2, miXture of two isomers), 4.03 (s, 3H, OMe, major isomer), 4.02 (s, 3H, OMe, minor isomer), 4.01 (s, 3H, OMe, major isomer), 3.88 (s, 3H, OMe, minor isomer), 3.83 (d, 1H, J
= 13.9 Hz, CH2, minor isomer), 3.82 (s, 3H, OMe, major isomer), 3.79 (s, 3H, OMe, minor isomer), 3.74 (d, 1H, J = 13.9 Hz, major isomer), 2.47–2.51 (m, 1H, CH2N, major isomer), 2.39–2.42 (m, 2H, CH2N,
miXture of two isomers), 2.34–2.36 (m, 2H, CH2N, CH2, miXture of two isomers), 2.09–2.14 (m, 1H, CH2, minor isomer), 1.73–1.89 (m, 4H, 2 CH2, 2 OH, miXture of two isomers). 13C NMR (150 MHz, CDCl3), (δ,
ppm) (miXture of two isomers): 169.5, 168.9, 152.3, 152.2, 148.5,
147.7, 147.5, 146.3, 146.1, 140.6, 140.5, 140.4, 136.5, 136.4, 134.1,
134.0, 132.1, 131.5, 128.9, 128.8, 128.6, 128.5, 127.0, 126.8, 123.7,
122.9, 120.1, 119.9, 118.2, 118.1, 117.9, 116.5, 116.1, 102.6, 102.5,
100.8, 100.7, 81.3, 80.8, 66.8, 66.7, 65.0, 64.5, 62.2, 62.1, 59.5, 59.3,
59.1, 57.8, 56.6, 56.6, 52.9, 52.4, 46.6, 46.3, 26.7, 25.6, HRMS (ESI):
[M H]+ calculated for C32H33N4O8, 601.2298; found, 601.2352. (S)-3-((R)-9-bromo-6-((1-(4-bromophenyl)-1H-1,2,3-triazol-4-yl)
methyl)-4-methoXy-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-
56.6, 55.5, 52.8, 46.3, 26.3, HRMS (ESI): [M + H]+ calculated for
C31H31N4O8, 587.2142; found, 587.2211.
5-yl)-6,7-dimethoXyisobenzofuran-1(3H)-one 5a: Yield: 90%, yellow powder, m.p.: 176–178 ◦C,
1HNMR (600 MHz,
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(2-hydroXy-3-phenoX- ypropyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo [4,5-g]isoquinolin-5-yl)isobenzofuran-1(3H)-one 4k:
Yield: 95%, pale-yellow solid, mp 78–82 ◦C. MiXture of two isomers
(53:47), 1H NMR (600 MHz, CDCl3): δ = 7.86 (s, 1H, HTriazole, minor
isomer), 7.81 (s, 1H, HTriazole, major isomer), 7.24–7.28 (m, 4H, HAr, miXture of two isomer), 6.94–6.96 (m, 2H, HAr, miXture of two isomers),
6.90 (d, 4H, J = 8.2 Hz, HAr, miXture of two isomers), 6.30 (s, 1H, HAr, minor isomer), 6.29 (s, 1H, HAr, major isomer), 5.99 (d, 2H, J = 8.1 Hz, HAr, miXture of two isomers), 5.93 (s, 2H, O-CH2-O, miXture of two isomers), 5.91 (s, 2H, O-CH2-O, miXture of two isomers), 5.68 (d, 1H, J
= 4.2 Hz, CH-O, minor isomer), 5.67 (d, 1H, J = 4.1 Hz, major isomer),
CDCl3) δ (ppm): 8.30 (s, 1H), 7.79 (d, J = 8.8 Hz, 2H), 7.64 (d, J = 8.8
Hz, 2H), 6.95 (d, J = 8.2 Hz, 1H), 6.10 (d, J = 8.2 Hz, 1H), 6.03 (s, 2H),
5.70 (d, J = 4.1 Hz, 1H), 4.48 (d, J = 4.1 Hz, 1H), 4.06 (s, 3H), 4.05 (d, J
= 14.0 Hz, 1H), 4,02 (s, 3H), 3.84 (s, 3H), 3.80 (s, J = 14.0 Hz, 1H),
2.51–2.60 (m, 1H), 2.44–2.50 (m, 1H), 2.13–2.19 (m, 1H), 1.91–1.98
(m, 1H), 13CNMR (150 MHz, CDCl3) δ (ppm): 168.8, 152.5, 148.0,
147.2, 146.9, 140.3, 139.9, 136.3, 134.3, 132.8, 130.3, 121.9, 121.8,
121.7, 119.9, 118.3, 118.1, 117.7, 101.2, 96.0, 80.2, 62.3, 59.7, 58.5,
56.7, 52.1, 45.8, 24.5, HRMS: [M H]+ calcd 712.0163, found
714.3456.
(S)-3-((R)-9-bromo-4-methoXy-6-((1-(pyridin-3-yl)-1H-1,2,3-triazol- 4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-yl)-
4.78 (dd, 1H, J = 13.4, 1.6 Hz, CH2N, minor isomer), 4.63 (dd, 1H, J =
13.9, 3.0 Hz, CH2N, major isomer), 4.54–4.57 (m, 3H, 3 CH2N, miXture
6,7-dimethoXyisobenzofuran-1(3H)-one 5b:
Yield: 90%, yellow powder, m.p.: 107–109 ◦C,
1H NMR (600 MHz,
of two isomers), 4.39–4.49 (m, 3H, CH2N, 2 CHOH, miXture of two isomers), 3.96–4.05 (m, 6H, 6 CH2, miXture of two isomers), 4.04 (s, 3H, OMe, minor isomer), 4.03 (s, 3H, OMe, major isomer), 4.03 (s, 3H, OMe, major isomer), 4.01 (s, 3H, OMe, minor isomer), 3.82 (s, 3H, OMe, major isomer), 3.81 (s, 3H, OMe, minor isomer), 3.76 (d, 2H, J = 14.9 Hz,
miXture of two isomers), 2.36–2.48 (m, 4H, CH2N, miXture of two iso- mers), 2.21–2.29 (m, 2H, CH2, miXture of two isomers), 1.80–1.85 (m, 3H, CH2, 2OH, miXture of two isomers). 13C NMR (150 MHz, CDCl3), (δ,
ppm) (miXture of two isomers): 169.1, 169.0, 158.3, 158.2, 152.3,
148.5, 147.6, 147.5, 146.3, 140.5, 140.5, 140.4, 134.1, 134.0, 131.8,
131.7, 129.5, 129.4, 124.4, 124.2, 121.3, 120.1, 120.0, 118.2, 118.1,
117.9, 117.8, 116.2, 116.1, 114.5, 114.3, 102.6, 102.5, 100.7, 81.2,
81.0, 69.1, 69.0, 68.8, 68.7, 62.2, 62.1, 59.5, 59.4, 58.6, 58.1, 56.6,
53.5, 53.2, 52.8, 52.6, 46.6, 26.4, 26.1, HRMS (ESI): [M + H]+ calcu-
lated for C33H35N4O9, 631.2404; found, 631.2474.
(3S)-6,7-DimethoXy-3-((R)-4-methoXy-6-((1-(2-hydroXy-2-phenyl- ethyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo [4,5-g]isoquinolin-5-yl)isobenzofuran-1(3H)-one 4l:
Yield: 95%, pale-yellow solid, mp 72–74 ◦C. MiXture of two isomers
(52:48), 1H NMR (600 MHz, CDCl3): δ = 7.82 (s, 1H, HTriazole, major
isomer), 7.81 (s, 1H, HTriazole, minor isomer), 7.29–7.33 (m, 6H, HAr, miXture of two isomers), 7.20 (d, 2H, J = 7.0 Hz, HAr, minor isomer),
7.19 (d, 2H, J = 7.0 Hz, HAr, major isomer), 6.91 (d, 1H, J = 8.2 Hz, HAr, major isomer), 6.88 (d, 1H, J = 8.2 Hz, HAr, minor isomer), 6.29 (s, 1H, HAr, major isomer), 6.28 (s, 1H, HAr, minor isomer), 6.03 (d, 1H, J = 8.2 Hz, HAr, minor isomer), 5.97 (d, 1H, J = 8.2 Hz, HAr, major isomer), 5.93 (s, 2H, O-CH2-O, miXture of two isomers), 5.91 (s, 2H, O-CH2-O, miXture of two isomers), 5.82 (dd, 1H, J = 9.1, 3.7 Hz, CH-OH, minor isomers), 5.68–5.70 (m, 2H, CH-OH, CH-O, major isomer), 5.65 (d, 1H, J = 4.0 Hz,
CDCl3) δ (ppm): 9.20 (d, J = 2.5 Hz, 1H), 8.67 (dd, J = 4.8, 1.3 Hz, 1H),
8.36 (s, 1H), 8.20–8.27 (m, 1H), 7.44–7.52 (m, 1H), 6.95 (d, J = 8.2 Hz,
1H), 6.10 (d, J = 8.2 Hz, 1H), 6.03 (s, 2H), 5.70 (d, J = 4.0 Hz, 1H), 4.49
(d, J = 4.0 Hz, 1H), 4.08 (d, J = 13.0 Hz, 1H), 4.07 (s, 3H), 4.03 (s, 3H),
3.83 (s, 3H), 3.82 (d, J 13.0 Hz, 1H), 2.52–2.58 (m, 1H), 2.44–2.50 (m,
1H), 2.14–2.20 (m, 1H), 2.94–1.98 (m, 1H), 13C NMR (150 MHz, CDCl3)
δ (ppm): 168.8, 152.5, 149.5, 148.0, 147.4, 146.9, 140.0, 134.3, 133.8,
130.9, 130.3, 128.8, 127.6, 124.2, 121.9, 119.9, 118.3, 118.1, 117.7,
101.2, 96.0, 80.3, 62.3, 59.7, 58.6, 56.7, 52.1, 45.9, 24.6, HRMS: [M
H]+ calcd 636.1010, found 637.9719.
(S)-3-((R)-9-bromo-6-((1-(4-fluorobenzyl)-1H-1,2,3-triazol-4-yl)
methyl)-4-methoXy-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin- 5-yl)-6,7-dimethoXyisobenzofuran-1(3H)-one 5c:
Yield: 90%, yellow powder, m.p.: 86–88 ◦C, 1H NMR (600 MHz,
CDCl3) δ (ppm): 7.66 (s, 1H), 7.28 (dd, J = 8.6, 5.2 Hz, 2H), 7.01–7.11
(m, 2H), 6.93 (d, J = 8.2 Hz, 1H), 6.10 (d, J = 8.2 Hz, 1H), 6.01 (s, 2H),
5.60 (d, J = 4.3 Hz, 1H), 5.48 (d, J = 14.0 Hz, 1H), 5.45 (d, J = 14.0 Hz,
1H), 4.47 (d, J = 4.3 Hz, 1H), 3.99 (s, 3H), 3.97 (s, 3H), 3.96 (d, J = 13.0
Hz, 1H), 3.82 (s, 3H), 3.77 (s, J 13.0 Hz, 1H), 2.50–2.56 (m, 1H),
2.39–2.45 (m, 1H), 2.24–2.30 (m, 1H), 1.83–1.90 (m, 1H), 13C NMR
(150 MHz, CDCl3) δ (ppm): 168.4, 152.4, 147.8, 146.7, 146.4, 140.5,
139.9, 134.3, 130.8, 130.0, 129.9, 123.4, 119.8, 118.4, 118.2, 117.7,
116.0, 115.9, 101.1, 95.9, 80.5, 62.2, 59.6, 58.7, 56.7, 53.3, 52.0, 45.5,
24.9, HRMS: [M H]+ calcd 667.1120, found 667.1217.
(S)-3-((R)-9-bromo-4-methoXy-6-((1-(p-tolyl)-1H-1,2,3-triazol-4-yl) methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-yl)-6,7-
dimethoXyisobenzofuran-1(3H)-one 5d:
Yield: 85%, yellow powder, m.p.: 113–116 ◦C, 1H NMR (600 MHz, CDCl3) δ (ppm): 8.21 (s, 1H), 7.72 (d, J = 8.2 Hz, 2H), 7.29 (d, J = 8.2
Hz, 2H), 6.95 (d, J = 8.2 Hz, 1H), 6.14 (d, J = 8.2 Hz, 1H), 6.02 (s, 2H),
5.67 (d, J = 4.3 Hz, 1H), 4.52 (d, J = 4.3 Hz, 1H), 4.05 (s, 3H), 4.06 (d, J
isomers)), 5.10–5.22 (m, 2H, O-CH2 (miXture of two isomers)), 5.04 (d, 2H, J = 14.9 Hz, O-CH2 (miXture of two isomers)), 4.43–4.59 (m, 2H,
= 14.0 Hz, 1H), 4,00 (s, 3H), 3.84 (d, J = 14.0 Hz, 1H), 3.83 (s, 3H),
NTriazole-CH2
(miXture
of two isomers)), 4.35–4.43 (m, 2H, N-CH
2.52–2.61 (m, 1H), 2.42–2.50 (m, 1H), 2.40 (s, 3H), 2.20–2.27 (m, 1H),
1.89–1.95 (m, 1H), 13C NMR (150 MHz, CDCl3) δ (ppm): 168.6, 152.5,
147.9, 146.8, 146.5, 140.5, 140.0, 138.4, 135.0, 134.3, 130.3, 130.1,
121.6, 120.1, 119.8, 118.4, 118.2, 117.7, 101.1, 95.9, 80.4, 62.3, 59.6,
58.6, 56.7, 52.0, 45.7, 24.8, 21.1, HRMS: [M H]+ calcd 649.1214,
found 649.1348.
(S)-3-((R)-9-bromo-6-((1-(4-fluorophenyl)-1H-1,2,3-triazol-4-yl) methyl)-4-methoXy-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-
5-yl)-6,7-dimethoXyisobenzofuran-1(3H)-one 5e:
Yield: 85%, yellow powder, m.p.: 182–184 ◦C, 1H NMR (600 MHz, CDCl3) δ (ppm): 8.26 (s, 1H), 7.87 (dd, J = 8.3, 2.2 Hz, 2H), 7.64 (t, J =
8.3 Hz, 2H), 6.95 (d, J = 8.2 Hz, 1H), 6.11 (d, J = 8.2 Hz, 1H), 6.03 (s,
2H), 5.70 (d, J = 4.0 Hz, 1H), 4.48 (d, J = 4.0 Hz, 1H), 4.06 (s, 3H), 4.05
(d, J = 12.0 Hz, 1H), 4.02 (s, 3H), 3.83 (s, 3H), 3.80 (d, J = 12.0 Hz, 1H),
2.52–2.58 (m, 1H), 2.44–2.50 (m, 1H), 2.12–2.20 (m, 1H), 1.91–1.98
(m, 1H), 13C NMR (150 MHz, CDCl3) δ (ppm): 168.8, 152.5, 148.0,
147.0, 146.8, 140.4, 140.0, 134.3, 133.6, 130.9, 128.8, 122.2, 122.1,
122.0, 119.8, 118.3, 118.2, 117.7, 101.2, 96.0, 80.41, 62.3, 59.6, 58.5,
56.7, 52.1, 45.8, 24.5, HRMS: [M H]+ calcd 653.0963, found
653.1042.
(S)-3-((R)-9-bromo-4-methoXy-6-((1-phenyl-1H-1,2,3-triazol-4-yl) methyl)-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinolin-5-yl)-6,7-
dimethoXyisobenzofuran-1(3H)-one 5f:
Yield: 85%, yellow powder, m.p.: 97–99 ◦C, 1H NMR (600 MHz, CDCl3) δ (ppm): 8.27 (s, 1H), 7.86 (d, J = 7.6 Hz, 2H), 7.47–7.54 (m,
2H), 7.39 (t, J = 7.4 Hz, 1H), 6.95 (d, J = 8.3 Hz, 1H), 6.14 (d, J = 8.3
Hz, 1H), 6.02 (s, 2H), 5.68 (d, J = 4.1 Hz, 1H), 4.51 (d, J = 4.1 Hz, 1H),
4.06 (d, J = 13.0 Hz, 1H), 4.05 (s, 3H), 4.00 (s, 3H), 3.84 (s, J = 13.0 Hz,
1H), 3.83 (s, 3H), 2.52–2.57 (m, 1H), 2.48–2.51 (m, 1H), 2.21–2.27 (m,
1H), 1.91–1.99 (m, 1H), 13C NMR (150 MHz, CDCl3) δ (ppm): 168.7,
152.5, 148.0, 146.8, 146.7, 140.5, 140.0, 137.3, 134.3, 130.3, 129.7,
128.4, 121.7, 120.2, 119.8, 118.3, 118.1, 117.7, 101.1, 95.9, 80.4, 62.3,
59.6, 58.5, 56.7, 52.1, 45.7, 24.7, HRMS: [M H]+ calcd 635.1058,
found 636.8440.
6-((1-(2,6-Dichlorophenyl)-1H-1,2,3-triazol-4-yl)methyl)-5-(4,5-
dimethoXy-1,3-dihydroisobenzofuran-1-yl)-4-methoXy-5,6,7,8-tetrahy- dro-[1,3]dioXolo[4,5-g]isoquinoline 6a:
Yield: 85%, yellow powder, m.p : 84–86 ◦C. 1H NMR (600 MHz,
CDCl3), (δ, ppm): 7.59 (s, 1H, HTriazole), 7.39–7.48 (m, 3H, HAr), 6.64 (d,
2H, J = 8.2 Hz, HAr), 6.30 (s, 1H, HAr), 6.18 (d, 2H, J = 8.2 Hz, HAr), 5.87
(d, 1H, J = 1.4 Hz, O-CH2O), 5.86 (d, 1H, J = 1.4 Hz, O-CH2O), 5.43(t,
1H, J = 3.4 Hz, O-CH), 5.24 (dd, 1H, J = 12.0, 2.6 Hz, CH2O), 5.07 (d,
1H, J = 12.0 Hz, CH2O), 4.45 (d, 1H, J = 4.1 Hz, N-CH), 4.23 (d, 1H, J =
14.5 Hz, N-CH2-CTriazole), 4.07 (d, 1H, J = 14.5 Hz, N-CH2-CTriazole), 3.86 (s, 3H, OMe), 3.79 (s, 3H, OMe), 3.78 (s, 3H, OMe), 2.85–2.89 (m, 1H, N- CH2), 2.53–2.59 (m, 2H, N-CH2, CH2), 2.18–2.23 (m, 1H, CH2).13C NMR (150 MHz, CDCl3), (δ, ppm): 169.4, 152.4, 148.6, 147.8, 147.7, 140.5,
140.4, 136.3, 134.1, 133.7, 132.2, 131.7, 131.4, 122.1, 121.8, 120.16,
119.2, 118.4, 117.9, 116.1, 102.6, 100.8, 80.9, 62.3, 59.5, 58.8, 56.6,
52.9, 46.5, 26.0, HRMS: [M H]+ calculated for C30H28Cl2N4O6,
611.13859; found, 611.14441.
2-(4-((5-(4,5-DimethoXy-1,3-dihydroisobenzofuran-1-yl)-4- methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl)methyl)-
1H-1,2,3-triazol-1-yl)-1-phenylethanol 6e:
Yield: 90%, yellow powder, m.p. 83–85 ◦C, 1H NMR (300 MHz, CDCl3), (δ, ppm): (miXture of two isomers (52:48)), 7.46 (s, 1H, HTriazole (major isomers)), 7.45 (s, 1H, HTriazole (minor isomers)), 7.33–7.39 (m, 6H, HAr (miXture of two isomers)), 7.16–7.25 (m, 4H, HAr (miXture of two isomers)), 6.65 (d, 2H, J = 8.2 Hz, HAr (miXture of two isomers)),
6.31 (s, 2H, HAr, (miXture of two isomers)), 6.19 (d, 2H, J = 8.2 Hz, HAr (major isomers)), 6.16 (d, 2H, J = 8.2 Hz, HAr (major isomers)), 5.89 (s, 4H, O-CH2O (miXture of two isomers)), 5.60–5.68 (m, 2H, NTriazole-CH2 (miXture of two isomers)), 5.37–5.45 (m, 2H, O-CH (miXture of two
(miXture of two isomers)), 3.76–4.21 (m, 26H, N-CH2, OMe, HO-CH, OH (miXture of two isomers)), 2.71–2.87 (m,2H, N-CH2 (miXture of two isomers)), 2.44–2.60 (m,4H, N-CH2, CH2 (miXture of two isomers)), 2.14–2.27 (m, 2H, CH2 (miXture of two isomers)), 13C NMR (150 MHz,
CDCl3), (δ, ppm) (miXture of two isomers): 151.01, 150.99, 147.93, 147.91, 146.86, 142.62, 142.49, 140.75, 140.68, 136.30, 136.23,
134.16, 134.09, 134.06, 134.02, 132.78, 132.72, 131.42, 131.16,
129.08, 129.06, 128.85, 128.79, 127.04, 126.96, 125.84, 123.37,
122.95, 118.33, 117.48, 111.65, 102.48, 102.44, 100.54, 86.77, 86.46,
71.53, 71.50, 66.94, 66.77, 65.37, 65.21, 60.86, 60.54, 59.93, 59.90,
59.18, 59.15, 56.22, 56.20, 52.17, 51.80, 46.34, 46.20, 31.59, 27.02,
26.91, 26.55, 25.27, 22.66, 14.14, HRMS: [M + H]+ calculated for
C32H34N4O7, 587.24275; found: 587.24750.
1-(4-((5-(4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)-4-
methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl)methyl)- 1H-1,2,3-triazol-1-yl)propan-2-ol 6f:
Yield: 70%, yellow powder, m.p. 62–65 ◦C, 1H NMR (600 MHz,
CDCl3), (δ, ppm):
(miXture of two isomers (56:44)), 7.49 (s, 1H, HTriazole (major iso- mers)), 7.47 (s, 1H, HTriazole (minor isomers)), 6.67 (d, 2H, J = 8.1 Hz, HAr (miXture of two isomers)), 6.31 (s, 2H, HAr, (miXture of two iso- mers)), 6.14 (d, 1H, J = 8.1 Hz, HAr (major isomers)), 6.13 (d, 1H, J =
8.1 Hz, HAr (minor isomers)), 5.90 (s, 4H, O-CH2O (miXture of two isomers)), 5.44 (br.s, 2H, O-CH (miXture of two isomers)), 5.21 (d, 2H, J
= 12.1 Hz, O-CH2 (miXture of two isomers)), 5.07 (d, 2H, J = 12.1 Hz, O-
CH2 (miXture of two isomers)), 4.35–4.51 (m, 4H, CH2 (miXture of two isomers)), 4.10–4.30 (m, 4H, N-CH, CH-OH (miXture of two isomers)), 3.78–4.04 (m, 22H, CH2, OMe (miXture of two isomers)), 3.21 (br.s, 2H, OH), 2.66–2.83 (m, 2H, N-CH2 (miXture of two isomers)), 2.42–2.62 (m, 4H, N-CH2, CH2 (miXture of two isomers)), 2.10–2.30 (m, 2H, CH2 (miXture of two isomers)), 1.39–1.63 (m, 4H, CH2 (miXture of two iso- mers)), 0.97–1.12 (m, 6H, CH3 (miXture of two isomers)), 13C NMR (150 MHz, CDCl3), (δ, ppm) (miXture of two isomers): 175.38, 151.34,
151.10, 148.01, 147.99, 146.37, 146.23, 142.51, 142.47, 140.70,
134.09, 133.98, 132.82, 131.22, 123.73, 117.92, 117.87, 117.62,
117.57, 112.70, 111.74, 102.51, 102.23, 100.88, 100.58, 86.55, 86.51,
71.58, 71.56, 66.79, 66.59, 60.67, 60.62, 60.00, 59.99, 59.22, 58.45,
57.13, 57.00, 56.42, 56.38, 56.21, 51.82, 51.79, 46.22, 46.16, 29.70,
26.60, 26.54, 22.65, 21.85, 20.44, 20.27, 20.15, 14.13, HRMS calcd for
C27H32N4O7 [M H]+ 539.25057, found 539.24750.
1-(4-((5-(4,5-DimethoXy-1,3-dihydroisobenzofuran-1-yl)-4-
methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl)methyl)- 1H-1,2,3-triazol-1-yl)-3-isopropoXypropan-2-ol 6g:
Yield: 70%, yellow powder, m.p. 70–72 ◦C, 1H NMR (600 MHz,
CDCl3), (δ, ppm): (miXture of two isomers), 7.53 (s, 2H, HTriazole (miXture of two isomers)), 6.34 (d, 2H, J = 8.3 Hz, HAr (miXture of two isomers)), 6.28 (s, 2H, HAr, (miXture of two isomers)), 6.13–6.15 (m, 2H, HAr (miXture of two isomers)), 5.86 (s, 4H, O-CH2O (miXture of two isomers)), 5.42 (br.s, 2H, O-CH (miXture of two isomers)), 5.17 (d, 2H, J
= 12.3 Hz, O-CH2 (miXture of two isomers)), 5.04 (d, 2H, J = 12.3 Hz, O- CH2 (miXture of two isomers)), 4.29–4.48 (m, 5H, N-CH, NTriazole-CH2 (miXture of two isomers)), 4.07–4.13 (m, 3H, CH-OH, N-CH2 (miXture of two isomers)), 3.78–4.00 (m, 22H, N-CH2, OMe, OH (miXture of two isomers)), 3.24–3.62 (m, 6H, CH2O, (CH3)2-CH (miXture of two iso- mers)), 2.65–2.83 (m, 2H, N-CH2 (miXture of two isomers)), 2.37–2.60 (m,4H, N-CH2, CH2 (miXture of two isomers)), 2.10–2.26 (m, 2H, CH2 (miXture of two isomers)), 1.15 (d, 12H, J 5.6 Hz, (CH3)2-CH (miXture of two isomers)), 13C NMR (150 MHz, CDCl3), (δ, ppm): 151.05, 147.94,
146.47, 142.57, 140.73, 134.10, 132.88, 131.38, 123.83, 118.19,
117.91, 117.52, 112.70, 111.69, 102.44, 100.55, 86.68, 72.41, 71.59,
69.53, 68.92, 60.95, 59.97, 59.20, 56.21, 52.90, 52.07, 46.15, 26.84,
21.98, HRMS: [M H]+ calcd for C30H38N4O8: 583.26896, found
583.27350.
1-(4-((5-(4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)-4- methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl)methyl)- 1H-1,2,3-triazol-1-yl)-3-phenoXypropan-2-ol 6h:
Yield: 95%, pale-yellow solid, mp 75–80 ◦C. MiXture of two isomers (51:49), 1H NMR (600 MHz, CDCl3): δ = 7.54 (s, 1H, HTriazole, minor
isomer), 7.26 (s, 1H, HTriazole, major isomer), 6.84–6.98 (m, 4H, HAr, miXture of two isomer), 6.61–6.65 (m, 2H, HAr, miXture of two isomers),
6.28 (s, 2H, J = 8.2 Hz, HAr, miXture of two isomers), 6.14 (s, 1H, HAr, minor isomer), 5.86 (s, 1H, HAr, major isomer), 5.42 (d, 2H, J = 8.1 Hz, HAr, miXture of two isomers), 5.13 (s, 2H, O-CH2-O, miXture of two isomers), 5.11 (s, 2H, O-CH2-O, miXture of two isomers), 5.01 (d, 1H, J
= 4.2 Hz, CH-O, minor isomer), 4.99 (d, 1H, J = 4.1 Hz, major isomer),
4.61 (dd, 1H, J = 13.4, 1.6 Hz, CH2N, minor isomer), 4.58 (dd, 1H, J =
13.9, 3.0 Hz, CH2N, major isomer), 4.54–4.57 (m, 3H, 3 CH2N, miXture of two isomers), 4.39–4.49 (m, 3H, CH2N, 2 CHOH, miXture of two isomers), 3.96–4.05 (m, 6H, 6 CH2, miXture of two isomers), 4.04 (s, 3H, OMe, minor isomer), 4.03 (s, 3H, OMe, major isomer), 4.03 (s, 3H, OMe, major isomer), 4.01 (s, 3H, OMe, minor isomer), 3.82 (s, 3H, OMe, major isomer), 3.81 (s, 3H, OMe, minor isomer), 3.76 (d, 2H, J = 14.9 Hz, miXture of two isomers), 2.36–2.48 (m, 4H, CH2N, miXture of two iso- mers), 2.21–2.29 (m, 2H, CH2, miXture of two isomers), 1.80–1.85 (m,
3H, CH2, 2 OH, miXture of two isomers). 13C NMR (150 MHz, CDCl3), (δ,
ppm) (miXture of two isomers): 175.41, 158.14, 158.11, 151.08, 151.07,
147.98, 146.75, 146.49, 142.51, 142.42, 140.70, 134.08, 134.02,
132.93, 132.84, 131.34, 131.26, 129.60, 129.53, 124.01, 123.87,
121.45, 121.19, 118.06, 117.96, 117.58, 117.57, 114.54, 114.47,
111.73, 102.46, 100.87, 100.57, 86.69, 86.62, 71.56, 69.05, 68.82,
68.70, 60.94, 60.80, 60.02, 59.99, 59.22, 59.19, 56.41, 56.21, 52.92,
52.87, 52.10, 51.89, 46.29, 46.23, 34.66, 31.59, 26.87, 26.73, 22.66,
21.87, 14.14, HRMS (ESI): [M 1] + calculated for C32 H33 N4 O8,
601.2298; found, 601.2352.
1-(allyloXy)-3-(4-((5-(4,5-dimethoXy-1,3-dihydroisobenzofuran-1-
yl)-4-methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl) methyl)-1H-1,2,3-triazol-1-yl)propan-1-ol 6i:
131.36, 129.67, 127.98, 122.22, 118.39, 117.44, 111.64, 102.44,
100.51, 86.65, 71.53, 60.76, 59.88, 59.13, 56.22, 53.81, 51.96, 46.07,
26.76, 21.17, HRMS calcd for C32H34N4O6 [M H]+ 570.24783, found
571.25293.
5-(4,5-DimethoXy-1,3-dihydroisobenzofuran-1-yl)-6-((1-(4-fluo-
robenzyl)-1H-1,2,3-triazol-4-yl)methyl)-4-methoXy-5,6,7,8-tetrahydro- [1,3]dioXolo[4,5-g]isoquinoline 6o:
Yield: 85%, yellow powder, m.p. 84–86 ◦C, 1H NMR (300 MHz,
CDCl3), (δ, ppm): 7.38 (s, 1H, HTriazole), 7.19–7.29 (m, 2H, HAr),
7.02–7.17 (m, 2H, HAr), 6.67 (d, 1H, J = 8.1 Hz, HAr), 6.32 (s, 1H, HAr),
6.16 (d, 1H, J = 8.1 Hz, HAr), 5.90 (s, 1H, O-CH2O), 5.91 (s, 1H, O-
CH2O), 5.48 (s, 2H, NTriazole-CH2), 5.39–5.45 (m, 1H, O-CH), 5.18 (d,
1H, J = 12.1 Hz, CH2O), 5.08 (d, 1H, J = 12.1 Hz, CH2O), 4.40 (d, 1H, J
= 4.3 Hz, N-CH), 4.10 (d, 1H, J = 14.5 Hz, N-CH2-CTriazole), 4.02 (d, 1H,
= 14.5 Hz, N-CH2-CTriazole), 3,87 (s, 3H, OMe), 3.85 (s, 3H, OMe), 3.83
(s, 3H, OMe), 2,71–2.87 (m,1H, N-CH2), 2.42–2.54 (m, 2H, N-CH2,
CH2), 2.12–2.30 (m, 1H, CH2), 13C NMR (150 MHz, CDCl3), (δ, ppm): 159.57, 151.06, 147.98, 142.69, 140.84, 138.49, 134.97, 134.25,
134.09, 132.84, 131.22, 130.77, 130.15, 121.98, 120.27, 117.57,
114.67, 111.70, 102.49, 100.56, 86.73, 71.56, 60.81, 59.95, 59.23,
56.22, 55.63, 52.06, 46.31, 26.82, 21.10, HRMS calcd for C31H31FN4O6
[M H]+ 573.22276, found 573.23197.
1-butoXy-3-(4-((5-(4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)-
4-methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]isoquinolin-6(5H)-yl) methyl)-1H-1,2,3-triazol-1-yl)propan-2-ol 6q:
Yield: 70%, yellow powder, m.p. 70–72 ◦C, 1H NMR (300 MHz,
CDCl3), (δ, ppm): (miXture of two isomers), 7.54 (s, 2H, HTriazole (miXture of two isomers)), 6.65 (d, 2H, J = 8.3 Hz, HAr (miXture of two isomers)), 6.30 (s, 2H, HAr, (miXture of two isomers)), 6.13 (d, 2H, J =
8.3 Hz, HAr (miXture of two isomers)), 5.89 (s, 4H, O-CH2O (miXture of two isomers)), 5.42 (br.s, 2H, O-CH (miXture of two isomers)), 5.23 (d, 2H, J = 12.3 Hz, O-CH2 (miXture of two isomers)), 5.07 (d, 2H, J = 12.3
Hz, O-CH2 (miXture of two isomers)), 4.21–4.68 (m, 5H, N-CH, NTriazole- CH2 (miXture of two isomers)), 4.04–4.17 (m, 3H, CH-OH, N-CH2
Yield: 75%, orange oil, m.p. 86–88 ◦C, 1H NMR (300 MHz, CDCl3), (δ,
(miXture of two isomers)), 3.78–4.00 (m, 22H, N-CH2, OMe, OH
ppm): (miXture of two isomers),7.57 (s, 2H, HTriazole (miXture of two isomer)), 6.67 (d, 2H, J = 8.4 Hz, HAr (miXture of two isomer)), 6.31 (s, 2H, HAr, (miXture of two isomer)), 6.14 (d, 2H, J = 8.4 Hz, HAr (miXture of two isomer)), 5.82–5.93 (m, 6H, O-CH2O, HC = C (miXture of two isomer)), 5.44 (br.s, 2H, O-CH (miXture of two isomer)), 5.17–5.39 (m, 8H, O-CH2, C = CH2, CH-OH, (miXture of two isomer)), 5.05–5.09 (d, 2H, J = 12.1 Hz, O-CH2 (miXture of two isomer)), 3.83–4.42 (m, 24H, N- CH, N-CH2, OMe (miXture of two isomer)), 3.27–3.58 (m, 4H, CH2 (miXture of two isomer)), 2.66–2.87 (m, 2H, N-CH2, (miXture of two
isomer)), 2.43–2.66 (m, 4H, N-CH2, CH2 (miXture of two isomer)), 2.12–2.30 (m, 2H, CH2 (miXture of two isomer)), 13C NMR (150 MHz, CDCl3), (δ, ppm): 151.06, 147.92, 142.54, 142.51, 140.73, 134.31,
132.93, 131.43, 123.73, 123.69, 118.32, 117.69, 117.53, 111.67,
102.45, 100.56, 86.71, 72.41, 71.59, 70.98, 70.86, 69.44, 69.24, 60.92,
60.86, 59.99, 59.24, 56.21, 52.87, 52.81, 52.23, 52.17, 46.33, 26.95, HRMS calcd for C30H36N4O8 [M H]+ 581.25331, found 581.25800.
5-(4,5-DimethoXy-1,3-dihydroisobenzofuran-1-yl)-4-methoXy-6-((1- (4-methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetrahydro-
(miXture of two isomers)), 3.24–3.62 (m, 6H, CH2O, (CH3)2-CH (miXture of two isomers)), 2.65–2.83 (m, 2H, N-CH2 (miXture of two isomers)), 2.37–2.60 (m,4H, N-CH2, CH2 (miXture of two isomers)), 2.10–2.26 (m, 2H, CH2 (miXture of two isomers)), 1.15 (d, 12H, J 5.6 Hz, (CH3)2-CH (miXture of two isomers)), 13C NMR (150 MHz, CDCl3), (δ, ppm):
151.12, 147.94, 146.41, 142.49, 140.63, 134.17, 133.97, 132.81,
131.24, 123.99, 118.16, 117.60, 111.71, 102.59, 100.57, 86.47, 71.54,
70.31, 60.45, 60.29, 59.97, 59.25, 56.21, 51.90, 46.33, 27.14, 26.56,
26.54, HRMS calcd for C30H38N4O8, [M H]+, 583.26896, found
583.27350.
(R)-9-bromo-5-((S)-4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)-
6-((1-(4-fluorobenzyl)-1H-1,2,3-triazol-4-yl)methyl)-4-methoXy- 5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g]isoquinoline 7a.
Yield: 90%, Light yellow solid, m. p. : 65–67 ◦C, 1H NMR (300 MHz,
CDCl3), (δ, ppm): 7.39 (s, 1H, Htriazole), 7.26 – 7.20 (m, 2H, HAr),
7.09–7.06 (m, 2H, HAr), 6.69 (d, 1H, J = 8.1 Hz, HAr), 6.33 (d, 1H, J =
8.1 Hz, HAr), 5.99 (s, 1H, O-CH2-O), 5.96 (s, 1H, O-CH2-O), 5.48 (d, 1H,
J = 15.0 Hz, CH2-Ntriazole), 5.45(d, 1H, J = 15.0 Hz, CH2-Ntriazole), 5.37
[1,3]dioXolo[4,5-g]isoquinoline 6k.
Yield: 85%, yellow powder, m.p. 58–60 ◦C,
1H NMR (600 MHz,
(br s, 1H, CH-O), 5.08 (d, 1H, J = 12.0 Hz, CH2-O), 5.03(d, 1H, J = 12.0
Hz, CH2-O) 4.32 (d, 1H, J = 4.1 Hz, CH-N), 3.91 (d, 1H, J = 14.1 Hz,
CDCl3), (δ, ppm): 7.32 (s, 1H, HTriazole), 7.10–7.15 (m, 4H, HAr), 6.61 (d,
1H, J = 8.2 Hz, HAr), 6.27 (s, 1H, HAr), 6.12 (d, 1H, J = 8.2 Hz, HAr), 5.86
(d, 1H, J = 1.5 Hz, O-CH2O), 5.85 (d, 1H, J = 1.5 Hz, O-CH2O), 5.43 (d, 1H, J = 14.8 Hz, NTriazole-CH2), 5.39 (d, 1H, J = 14.8 Hz, NTriazole-CH2),
5.36–5.38 (m, 1H, O-CH), 5.14 (dd, 1H, J = 12.0, 2.6 Hz, CH2O), 5.06 (d,
1H, J = 12.0 Hz, CH2O), 4.36 (d, 1H, J = 4.2 Hz, N-CH), 4.04 (d, 1H, J =
CH2), 3.89 (d, 1H, J = 14.1 Hz, CH2), 3.84 (s, 3H, OMe), 3.82 (s, 3H,
OMe), 3.76 (s, 3H, OMe), 2.96–2.83 (m, 1H, CH2), 2.75–2.59 (m, 2H, CH2), 2.33 – 2.18 (m, 1H, CH2), HRMS calcd for C31H30BrFN4O6, [M H]+, 652.83228, found 653.8996.
(R)-9-bromo-5-((S)-4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)- 4-methoXy-6-((1-(p-tolyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8-tetra-
14.5 Hz, N-CH2-CTriazole), 3.90 (d, 1H, J = 14.5 Hz, N-CH2-CTriazole), 3.82 (s, 3H, OMe), 3.80 (s, 3H, OMe), 3.77 (s, 3H, OMe), 2.72–2.77 (m, 1H, N-
hydro-[1,3]dioXolo[4,5-g]isoquinoline 7b.
Yield: 90%, yellow powder, m.p. : 178–181 ◦C;
1H NMR (300 MHz,
CH2), 2.43–2.51 (m, 2H, N-CH2, CH2), 2.32 (s, 3H, CH3), 2.12–2.17 (m, 1H, CH2), 13C NMR (150 MHz, CDCl3), (δ, ppm): 150.97, 147.87,
146.81, 142.63, 140.73, 138.41, 134.22, 132.01, 132.74, 131.93,
CDCl3), (δ, ppm): 7.83 (s, 1H, Htriazole), 7.58 (d, 2H, J = 8.3 Hz, HAr),
7.30 (d, 2H, J = 8.3 Hz, HAr), 6.75 (d, 1H, J = 8.2 Hz, HAr), 6.43 (d, 1H, J
= 8.2 Hz, HAr), 5.98 (s, 1H, O-CH2-O), 5.97 (s, 1H, O-CH2-O), 5.44 (br s,
1H, CH-O), 5.21 (dd, 1H, J = 12.2, 1.9 Hz, CH2-O), 5.10 (d, 1H, J = 12.2
Hz, CH2-O), 4.40 (d, 1H, J = 4.6 Hz, CH-N), 4.07 (d, 1H, J = 14.4 Hz,
CH2), 3.94 (d, 1H, J = 14.4 Hz, CH2), 3.85 (s, 3H, OMe), 3.84 (s, 3H,
OMe), 3.83 (s, 3H, OMe), 3.06 – 2.92 (m, 1H, CH2), 2.81 – 2.62 (m, 2H,
CH2), 2.42 (s, 3H, CH3), 2.37–2.27 (m, 1H, CH2); 13C NMR (150 MHz,
CDCl3), (δ, ppm): 164.01, 150.97, 147.87, 146.81, 142.63, 140.73,
138.41, 134.22, 134.01, 132.74, 131.36, 129.67, 127.98, 122.22,
118.39, 117.44, 111.64, 102.44, 100.51, 86.65, 71.53, 60.76, 59.88,
59.13, 56.22, 53.81, 51.96, 46.07, 26.76, 21.17; HRMS calcd for C31H32 O6 N4 Br+ [M H]+ 635.15052, found 635.14807.
(RS)-1-(4-(((R)-9-bromo-5-((S)-4,5-dimethoXy-1,3-dihy- droisobenzofuran-1-yl)-4-methoXy-7,8-dihydro-[1,3]dioXolo[4,5-g]iso- quinolin-6(5H)-yl)methyl)-1H-1,2,3-triazol-1-yl)-3-phenoXypropan-2-
ol 7f.
Yield: 94% (51:49), Light yellow solid, m.p.: 60–63 ◦C, 1H NMR (300 MHz, CDCl3), (δ, ppm): (miXture of two diastreomers), 7.59 (s, 2H, Htriazole, (miXture of two diastreomers)), 7.32 (d, 4H, J = 7.2 Hz, HAr, (miXture of two diastreomers)), 6.99 (t, 2H, J = 7.0 Hz, HAr, (miXture of two diastreomers)), 6.93– 6.89 (m, 4H, HAr, (miXture of two dia- streomers)), 6.71 (d, 2H, J = 8.2 Hz, HAr, (miXture of two dia-
OH, CH-N, CH2, CH2-O, (miXture of two diastreomers)), 3.85 (s, 6H, OMe, (miXture of two diastreomers)), 3.84 (s, 6H, OMe, (miXture of two diastreomers)), 3.83 (s, 6H, OMe, (miXture of two diastreomers)), 3.51–3.34 (m, 4H, CH2-O, (miXture of two diastreomers)), 3.03–2.86 (m, 4H, CH2, OH, (miXture of two diastreomers)), 2.71–2.59 (m, 4H, CH2,
(miXture of two diastreomers)), 2.28–2.19 (m, 2H, CH2, (miXture of two diastreomers)), 13C NMR (150 MHz, CDCl3), (δ, ppm): 175.30, 151.05,
147.94, 146.47, 142.57, 140.73, 134.10, 132.88, 131.38, 123.83,
118.19, 117.60, 111.69, 100.55, 86.68, 72.41, 71.59, 69.53, 68.92,
60.95, 59.97, 59.20, 56.21, 52.90, 52.07, 46.15, 26.84, 21.98, HRMS calcd for C30H35 O8 N4Br+ [M H]+ 659.53400, found 660.52360.
Compound 8:
N-nornoscapine (1.3 g, 3 mmol) was dissolved in 15-mL ACN and K2CO3 (0.83 g, 6 mmol). Then the alkyl halide was added (4.5 mmol) to the flask. The reaction miXture was refluXed for 24 h, then extracted with ethyl acetate (3 × 30 mL) and the organic layer was isolated and dried over anhydrous Na2SO4. This product was purified by column chromatography on silica gel (eluent: n-hexane: dichloromethane) to give N-alkyl N-nornoscapine compounds.
N-alkyl nornoscapine compound (4 mmol) was dissolved in 10-mL
streomers)), 6.31 (d, 2H, J = 8.2 Hz, HAr, (miXture of two
dried THF in 0 ◦C. LiAlH4 (0.304 g, 8 mmol) was added to the solu-
diastreomers)), 5.98 (s, 4H, O- CH2-O, (miXture of two diastreomers)),
5.41 (br s, 2H, CH-O, (miXture of two diastreomers)), 5.13 (d, 2H, J =
12.2 Hz, CH2-O, (miXture of two diastreomers)), 5.04 (d, 2H, J = 12.2 Hz, CH2-O, (miXture of two diastreomers)), 4.72 – 4.37 (m, 6H, CH2- Ntriazole, CH-OH, (miXture of two diastreomers)), 4.35 (d, 2H, J = 3.6 Hz, CH-N, (miXture of two diastreomers)), 4.04 – 3.76 (m, 26H, CH2-tri- azole, CH2-CHOH, 3OMe, (miXture of two diastreomers)), 2.99 – 2.74 (m, 2H, CH2, (miXture of two diastreomers)), 2.74 – 2.54 (m, 4H, CH2, (miXture of two diastreomers)), 2.36 – 2.10 (m, 2H, CH2, (miXture of two diastreomers)), 13C NMR (150 MHz, CDCl3), (δ, ppm): 158.07, 158.05,
151.18, 146.10, 142.65, 140.27, 134.30, 134.12, 132.59, 132.53,
129.72, 129.64, 124.01, 123.96, 121.55, 117.36, 114.46, 111.88,
100.90, 95.92, 86.18, 86.16, 77.24, 77.02, 71.58, 71.56, 69.68, 68.91,
68.72, 68.63, 60.77, 60.66, 60.01, 59.26, 59.24, 56.26, 52.85, 52.78,
51.22, 51.09, 45.36, 25.28, 25.22, HRMS calcd for C33H35 O8 N4 Br+ [M
H]+ 694.16383.
(R)-9-bromo-5-((S)-4,5-dimethoXy-1,3-dihydroisobenzofuran-1-yl)-
4-methoXy-6-((1-(4-nitrophenyl)-1H-1,2,3-triazol-4-yl)methyl)-5,6,7,8- tetrahydro-[1,3]dioXolo[4,5-g]isoquinoline 7g.
Yield: 95%, Light yellow solid, m.p.: 155–177 ◦C, 1H NMR (300 MHz,
CDCl3), (δ, ppm): 8.43 (d, 2H, J = 9.0 Hz, HAr), 7.99 (s, 1H, Htriazole),
7.96 (d, 2H, J = 9.0 Hz, HAr), 6.76 (d, 1H, J = 8.2 Hz, HAr), 6.34 (d, 1H, J
= 8.2 Hz, HAr), 6.02 (s, 1H, O- CH2-O), 6.01 (s, 1H, O- CH2-O), 5.52–5.48
(m, 1H, CH-O), 5.25 (dd, 1H, J = 12.4, 2.2 Hz, CH2-O), 5.14 (d, 1H, J =
12.4 Hz, CH2-O), 4.41 (d, 1H, J = 4.2 Hz, CH-N), 4.13 (d, 1H, J = 14.9
Hz, CH2), 3.95 (d, 1H, J = 14.9 Hz, CH2), 3.90 (s, 3H, OMe), 3.88 (s, 3H,
OMe), 3.86 (s, 3H, OMe), 2.96 – 2.81 (m, 1H, CH2), 2.74–2.65 (m, 2H,
CH2), 2.39 – 2.25 (m, 1H, CH2), 13C NMR (150 MHz, CDCl3), (δ, ppm): 151.16, 147.10, 142.75, 140.44, 138.53, 134.90, 134.31, 132.47,
130.14, 129.38, 128.20, 121.01, 120.43, 120.27, 120.10, 117.45,
111.82, 100.89, 95.94, 86.18, 86.07, 71.50, 60.09, 59.84, 59.36, 59.11,
56.37, 56.11, 21.26, 20.95, HRMS calcd for C30H28 O8 N5Br+ [M H]+
666.11213, found 666.11743.
(RS)-1-(allyloXy)-3-(4-(((R)-9-bromo-5-((S)-4,5-dimethoXy-1,3- dihydroisobenzofuran-1-yl)-4-methoXy-7,8-dihydro-[1,3]dioXolo[4,5-
g]isoquinolin-6(5H)-yl)methyl)-1H-1,2,3-triazol-1-yl)propan-2-ol 7j.
Yield: 94% (51:49), Light yellow oil, 1H NMR (300 MHz, CDCl3), (δ, ppm): (miXture of two diastreomers), 7.59 (s, 2H, Htriazole, (miXture of two diastreomers)), 6.73 (d, 2H, J = 8.2 Hz, HAr, (miXture of two dia- streomers)), 6.33 (d, 2H, J = 8.2 Hz, HAr, (miXture of two dia- streomers)), 6.00 (s, 2H, O- CH2-O, (miXture of two diastreomers)), 5.98 (s, 2H, O- CH2-O, (miXture of two diastreomers)), 5.96 – 5.81 (m, 2H,
=CH, (miXture of two diastreomers)), 5.41 (br s, 2H, O-CH, (miXture of
two diastreomers)), 5.40–5.05 (m, 8H, =CH2cis, =CH2trans, CH2-O, (miXture of two diastreomers)), 4.57 – 3.90 (m, 16H, Ntriazole-CH2, CH-
tion portionwise in 15 min. After complete addition, the reaction tem- perature was raised to 40 C and stirred for 2 h. The reaction was quenched with ice water and partitioned by aqueous ammonium chlo- ride (2 25 mL) and ethyl acetate (2 30 mL). The organic layers were combined, washed with brine and dried with sodium sulfate. The solvent was evaporated under reduced pressure. The crude diol was purified by column chromatography on silica gel (n-hexane: EtOAc).
The diol (1.6 g, 4 mmol) was dissolved in a solution of imidazole (68 mg, 1 mmol) in DMF (10 mL). tert-Butyl dimethyl silyl chloride (0.63 g,
4.8 mmol) was added to the reaction miXture and stirred at ambient temperature overnight. The reaction miXture was poured in ice water and extracted with dichloromethane (3 25 mL). The combined organic layers were washed with brine and water and then dried over sodium sulfate. The solvent was removed under reduced pressure using rotary evaporator. The oily residue was purified by column chromatography on
silica gel (n-hexane: dichloromethane) to give compound 8.
Yield: 90%, Off-white solid, mp: 98–100 ◦C,1H NMR (600 MHz, CDCl3), (δ, ppm): (d, J = 8.6 Hz, 1H, HAr), 6.89 (d, J = 8.6 Hz, 1H, HAr),
6.31 (s, 1H, HAr), 5.83 (s, 1H, O–CH2–O), 5.82 (s, 1H, OCH2O), 4.82 (d,
J = 11.6 Hz, 1H, CH2OH), 4.62 (d, J = 8.5 Hz, 1H, CH–O), 4.45 (d, J =
11.6 Hz, 1H, CH2OH), 4.01 (s, 3H, O–CH3), 3.95 (d, J = 8.5 Hz, 1H,
CH–N), 3.79 (s, 6H, 2O–CH3), 2.98–3.17 (m, 1H, CH2 –N), 2.65–2.68 (m,
1H, CH2 –N), 2.41–2.57 (m, 1H, CH2), 2.28–2.32 (m, 1H, CH2), 1.92 (s,
3H, N–CH3), 13C NMR (150 MHz,CDCl3) δ 151.5, 148.2, 146.2, 141.8,
136.5, 134.5, 134.0 130.4, 122.1, 118.5, 112.3, 103.0, 100.9, 73.6,
65.2, 61.6, 59.4, 55.9, 54.5, 49.5, 43.9, 26.9, HRMS (ESI): m/z [M + H]+
calcd for C22H28NO7: 418.1860; found: 418.1937.
1H NMR (600 MHz,CDCl3) δ = 6.70 (d, J = 8.6 Hz, 1H, HAr), 6.60 (d,
J = 8.6 Hz, 1H, HAr), 6.11 (s, 1H, HAr), 5.66 (d, J = 1.5 Hz, 1H,
O–CH2–O), 5.65 (d, J = 1.5 Hz, 1H, O–CH2–O), 5.00 (d, J = 5.0 Hz, 1H,
CH–O), 4.71 (d, J = 10.5 Hz, 1H, CH2OH), 4.58 (d, J = 10.5 Hz, 1H, CH2
OH), 4.11 (d, J = 5.0 Hz, 1H, CH–N), 3.68 (s, 3H, O–CH3), 3.67 (s, 3H,
O–CH3), 3.51 (s, 3H, O–CH3), 2.90–2.95 (m, 1H, CH2 –N), 2.37 (s, 3H,
N–CH3), 2.23–2.35 (m, 3H, CH2 –N, 2CH2), 0.78 (s, 9H, t-Bu), 0.00 (s,
6H, 2CH3), 13C NMR (150 MHz, CDCl3), (δ, ppm): 151.3, 147.6, 146.9,
140.9, 134.5, 133.4,132.5,131.8, 123.3, 118.6, 110.9, 101.9, 100.3,
73.2, 63.5, 61.4, 58.5, 56.2, 55.7, 50.3, 44.9, 28.7, 26.0, 25.7, 18.3,
5.2, HRMS (ESI): m/z [M H] + calcd for C28H41NO7 Si: 531.2652;
found: 532.4829.
(S)-(2-(((tert-butyldimethylsilyl)oXy)methyl)-3,4-dimethoXyphenyl) ((R)-4-methoXy-6-(4-methoXybenzyl)-5,6,7,8-tetrahydro-[1,3]dioXolo [4,5-g]isoquinolin-5-yl)methanol 8b:
1H NMR (600 MHz, CDCl3): δ = 7.05 (d, 1H, J = 8.1 Hz, HAr), 6.95 (d,
1H, J = 8.1 Hz, HAr), 6.78 (m, 4H, HAr),6.35 (s, 1H, HAr), 5.89 (s, 1H, O-
CH2-O), 5.86 (s, 1H, O-CH2-O), 5.16 (d, 1H, J = 6.9 Hz, CH-O), 4.86 (d,
1H, J 10.8 Hz, CH2), 4.76 (d, 1H, J 10.8 Hz, CH2), 4.38 (d, 1H, J
6.9 Hz, CH-N), 3.87 (s, 3H, OMe), 3.84 (s, 3H, OMe), 3.80 (s, 3H, OMe),
3.79 (s, 3H, OMe), 3.74 (d, 1H, J = 13.1 Hz, CH2), 3.55 (d, 1H, J = 13.1
Hz, CH2), 3.06–3.18 (m, 1H, CH2), 2.34–2.68 (m, 3H, CH2), 0.91 (s, 9H, CH3), 0.12 (s, 6H, CH3), 13C NMR (150 MHz, CDCl3): δ 158.56,
151.37, 147.82, 146.86, 141.40, 135.70, 133.87, 132.67, 131.34,
131.04, 130.03, 129.40, 123.36, 119.45, 113.78, 113.42, 111.31,
102.57, 100.44, 73.26, 71.46, 61.53, 61.50, 59.68, 58.98, 56.28, 55.77,
55.27, 55.21, 45.61, 26.72, 26.00, 18.33, 5.20, 5.22.
(3S)-(2-(((tert-butyldimethylsilyl)oXy)methyl)-3,4-dimethoX- yphenyl)((R)-6-(cyclopropylmethyl)-4-methoXy-5,6,7,8-tetrahydro- [1,3]dioXolo[4,5-g]isoquinolin-5-yl)methanol 8c:
1H NMR (600 MHz, CDCl3): δ = 6.87 (br s, 1H, HAr), 6.73 (d, 1H, J =
8.6 Hz, HAr), 6.27 (s, 1H, HAr), 5.79 (s, 2H, O-CH2-O), 5.06 (br s, 1H, CH-
O), 4.79 (d, 1H, J 10.6 Hz, CH2), 4.72 (br s, 1H, CH2), 4.41 (br s, 1H,
CH-N), 3.80 (s, 3H, OMe), 3.78 (s, 3H, OMe), 3.62 (s, 3H, OMe), 3.29 (br
s, 1H, CH2N), 2.49 (br s, 5H, CH2), 0.88 (s, 9H, CMe3), 0.80–0.88 (m, 1H,
CH), 0.44 (br s, 2H, CH2), 0.09 (s, 6H, CH3) 0.05–0.1 (m 2H, CH2). 13C
NMR (150 MHz, CDCl3), (δ, ppm): 151.7, 148.3, 146.4, 141.1, 137.0,
134.8, 133.4, 132.6, 123.2, 118.6, 11.3, 102.0, 100.3, 72.8, 66.0, 61.6,
61.4, 58.6, 56.2, 55.7, 47.1, 26.0, 25.8, 18.3, 9.6, 3.64, —5.2, HRMS
(ESI): [M H] calculated for C31H45NO7Si, 572.3043; found, 572.3054.
(S)-((R)-6-(4-bromobenzyl)-4-methoXy-5,6,7,8-tetrahydro-[1,3] dioXolo[4,5-g]isoquinolin-5-yl)(2-(((tert-butyldimethylsilyl)oXy) methyl)-3,4-dimethoXyphenyl)methanol 8d:
1H NMR (600 MHz, CDCl3): δ = 7.27 (m, 3H, HAr), 7.13 (s, 1H, HAr),
6.96 (d, 1H, J = 8.5 Hz, HAr), 6.78 (d, 1H, J = 8.5 Hz, HAr), 6.36 (s, 1H,
HAr), 5.88 (s, 1H, O-CH2-O), 5.87 (s, 1H, O-CH2-O), 5.18 (brs, 1H, CH-
O), 4.87 (d, 1H, J = 10.8 Hz, CH2), 4.77 (d, 1H, J = 10.8 Hz, CH2),
4.36 (brs, 1H, CH-N), 3.71–3.95 (m, 11H, CH2, 3 CH3), 3.12–3.24 (m,
1H, CH2), 2.45–2.74 (m, 3H, CH2), 0.90 (s, 9H, CH3), 0.12 (s, 6H, CH3),
13C NMR (150 MHz, CDCl3), (δ, ppm): 151.45, 151.39, 147.97, 146.87,
146.81, 141.37, 133.85, 132.61, 131.01, 130.52, 130.46, 128.92,
128.07, 123.39, 123.25, 111.38, 111.34, 102.74, 102.54, 100.45, 73.40,
60.44, 59.35, 59.13, 58.96, 56.29, 55.78, 45.66, 26.72, 26.11, 25.98,
18.33, 8.37, 5.23.
(S)-((R)-6-benzyl-4-methoXy-5,6,7,8-tetrahydro-[1,3]dioXolo[4,5-g] isoquinolin-5-yl)(2-(((tert-butyldimethylsilyl)oXy)methyl)-3,4-dime- thoXyphenyl)methanol 8e:
1H NMR (600 MHz, CDCl3): δ = 7.21–7.29 (m, 3H, HAr), 7.10–7.16
(m, 2H, HAr), 7.00 (d, 1H, J = 8.5 Hz, HAr), 6.80 (d, 1H, J = 8.5 Hz, HAr),
6.37 (s, 1H, HAr), 5.88 (s, 1H, O-CH2-O), 5.87 (s, 1H, O-CH2-O), 5.19 (d,
1H, J = 6.9 Hz, CH-O), 4.89 (d, 1H, J = 10.8 Hz, CH2), 4.79 (d, 1H, J =
10.8 Hz, CH2), 4.44 (d, 1H, J = 6.9 Hz, CH-N), 3.88 (s, 6H, OMe), 3.84
(d, 1H, J = 13.1 Hz, CH2), 3.82 (s, 3H, OMe), 3.84 (d, 1H, J = 13.1 Hz,
CH2), 3.11–3.20 (m, 1H, CH2), 2.43–2.69 (m, 3H, CH2), 0.93 (s, 9H,
CH3), 0.14 (s, 6H, CH3), 13C NMR (150 MHz, CDCl3), (δ, ppm): 151.41, 147.88, 146.91, 141.41, 139.28, 135.68, 133.91, 132.65, 131.01,
128.91, 128.08, 126.89, 123.43, 119.44, 111.38, 102,59, 100.47, 73.38,
63.58, 61.83, 61.50, 60.47, 59.00, 56.31, 55.80, 45.73, 26.75, 26.02,
18.35, 8.37, —5.18, —5.20.
4.2. Proliferation assay
For the determination of potential effects of compounds listed in Table 1 on the proliferation capacity of MDA-MB-231 cells, 6 × 103 cells per well were seeded on 96-well plates in 100 µl Dulbecco’s Modified Eagle Medium (DMEM) without phenol red containing 10% heat-
inactivated fetal calf serum (FCS, Biochrom, Berlin, Germany), 100 U/ ml penicillin (PAN-Biotech, Aidenbach, Germany) and 100 µg/ml streptomycin (PAN-Biotech). The cells were cultivated under constant humidity at 37 ◦C in an atmosphere of 95% air and 5% CO2. 24 h after seeding, the cells were treated with indicated concentrations of the respective compound. DoXorubicin (300 nM) was used as a positive control. Untreated MDA-MB-231 cells were fiXed with a methanol-
ethanol (2:1) solution. After 72 h of incubation, the cells were washed with PBS, fiXated and stained with crystal violet (20% methanol, Sigma- Aldrich, Taufkirchen, Germany) for 15 min with gentle shaking. Sub- sequently, the crystal violet solution was removed, and the cells were washed with tap water before they were air-dried overnight. An acetic acid solution (20%, Sigma-Aldrich, Taufkirchen, Germany) was used to leach DNA-bound crystal violet from cells, and absorption was measured at 590 nm using a plate reader (Tecan Infinite F200 Pro, Tecan, Ma¨nnedorf, Switzerland). The potential effects on the relative prolifer- ation rate of MDA-MB-231 were determined, the obtained data from untreated control cells (fiXed after 24 h) were subtracted from values obtained from compound-treated cells.
According to the one-concentration screen guidelines of the national cancer institute (NCI 60 screening methodology), all compounds were tested at a concentration of 10 µM first. Only compounds reaching a defined threshold (1/3 higher activity of the reference substance noscapine at 10 µM) were further analyzed using a concentration of 1 µM. Then, again only compounds reaching the same defined threshold (1/3 higher activity of the reference substance noscapine at 1 µM) were used for IC50 determination. IC50 values of hit compounds were addi- tionally determined in other cancer cell types. Therefore, 1 105 HepG2
cells, 2.5 104 HeLa cells and 3.5 104 PC3 cells were treated with
respective concentrations and subsequently analyzed for proliferation.
Moreover, the Z score of this assay was calculated according to the following equation:
3(σp + σn)
|μp — μn|
The σp is the standard deviation of the mean of positive control and σn is the standard deviation of the mean of the negative control. The μp is the mean value of positive power and μn is the mean value of negative control.
4.3. Statistical analysis
The graphs were prepared using GraphPad Prism version 5.0 (San Diego, USA). IC50 values were obtained by applying a five-parameter logistic equation. All data were obtained by the performance of at least three independent experiments. The actual number of experiments
(n) is stated in the respective Figure legend. Data are represented as the mean value ± standard error of the mean.
4.4. A drug like property predication
The ligand structures were minimized using Lig Prep module implemented in Schrodinger 2015–2, using Maestro 10.2 platform. The drug-likeness properties of the most active compounds were predicted by using Qikprop 4.4 (Schro¨dinger, LLC).
4.5. Tubulin polymerization assay
Lyophilized tubulin was suspended in GAB buffer (10 mM NaPi, 30% glycerol, 1 mM EGTA, 0.1 mM GTP, pH 6.7) in the cold for 20 min. Then, the sample was centrifuged in Optima XPMax Ultracentrifuge at 50 000 rpm, 4 ◦C and 10 min to remove aggregates, tubulin concentration was measured and the protein was supplemented with 6 mM MgCl2 and 1
mM GTP. Subsequently, the 96 well plates were prepared by adding 100 uL of GAB buffer containing 25 uM tubulin followed by adding the compounds podophyllotoXin, 6p and 6A in a range of 1 uM to 30 uM. Controls including 0.5% DMSO and 27.5 uM noscapine were also added to the plates. The absorbance at a wavelength of 350 nm was measured in the Multiskan.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
We are also grateful to the Iran National Science Foundation (INSF, grant number 98026465) for financial support of this project and Shahid Beheshti University Research Council for providing facilities of to conduct this study. We thank Ganadería Fernando Díaz for the calf brains supply. This work was supported by CSIC PIE 201920E111 (MAO).
Appendix A. Supplementary material
Supplementary data to this article can be found online at https://doi. org/10.1016/j.bioorg.2021.105135.
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