The preparation method of 3-benzimidazolene derivative
A technology of benzimidazole and cyanomethylbenzimidazole, which is applied in the field of preparation of 3-benzimidazole chromene derivatives, can solve the problems of large amount of alkali, long reaction time, and low yield, and achieve convenient post-processing , low production cost and high yield
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Embodiment 1
[0028] Embodiment 1: the preparation method of 3-benzimidazole chromene derivative
[0029] Step 1) In a 25mL round bottom flask, add 2-cyanomethylbenzimidazole (1.0mmol), 2,3-dichlorobenzaldehyde (1.0mmol), 5,5-dimethyl-1,3-cyclo Hexandione (1.0 mmol), pyridine (0.1 mmol) and 2 mL of absolute ethanol were heated under reflux for 2 hours; during heating, the solvent was boiled.
[0030] Step 2) After the reaction is completed, cool to room temperature, a large amount of product precipitates out, suction filter, and wash the crude product with ethanol to obtain the pure product 2-amino-3-(1H-benzo[d]imidazole)-4-(2,3- Dichlorophenyl)-7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-one, the structural formula is as follows:
[0031]
[0032] Yield: 79%; Pale yellow solid; H NMR spectrum (DMSO-d 6 , 400MHz) (δ, ppm): 11.48(s, 1H), 7.84(d, J=8.4Hz, 1H), 7.80(s, 2H), 7.40-7.24(m, 4H), 7.06-7.00(m, 2H), 5.32(s, 1H), 2.62(d, J=17.6Hz, 1H), 2.47(d, J=18.0Hz, 1H), 2.32(d, J=16.0Hz, 1H)...
Embodiment 2
[0033] Embodiment 2: the preparation method of 3-benzimidazole chromene derivative
[0034] Step 1) Add 2-cyanomethylbenzimidazole (1.0mmol), 3-nitrobenzaldehyde (1.0mmol), 5,5-dimethyl-1,3-cyclohexanedione into a 25mL round bottom flask (1.0mmol), pyridine (0.1mmol) and absolute ethanol 2mL, react under reflux conditions for 1 hour;
[0035] Step 2) After the reaction is completed, cool to room temperature, a large amount of product precipitates, filter with suction, and wash the crude product with ethanol to obtain the pure product 2-amino-3-(1H-benzo[d]imidazole)-7,7-dimethyl -4-(3-nitrophenyl)-7,8-dihydro-4H-chromen-5(6H)-one, the structural formula is as follows:
[0036]
[0037] Yield: 85%; yellow solid; H NMR spectrum (DMSO-d 6 , 400MHz) (δ, ppm): 11.29(s, 1H), 8.36(s, 1H), 8.00-7.95(m, 3H), 7.83(d, J=7.6Hz, 1H), 7.53(t, J= 8.0Hz, 1H), 7.42(d, J=7.2Hz, 1H), 7.30(d, J=7.2Hz, 1H), 7.05-7.00(m, 2H), 5.19(s, 1H), 2.62(d, J=17.6Hz, 1H), 2.51(d, J=16.4Hz, 1H), 2.35(d,...
Embodiment 3
[0038] Embodiment 3: the preparation method of 3-benzimidazole chromene derivative
[0039] Step 1) In a 25mL round bottom flask, add 2-cyanomethylbenzimidazole (0.8mmol), 4-methoxybenzaldehyde (0.8mmol), 5,5-dimethyl-1,3-cyclohexanedi Ketone (0.8mmol), pyridine (0.08mmol) and absolute ethanol 2mL were reacted under reflux for 3 hours;
[0040] Step 2) After the reaction is finished, cool to room temperature, a large amount of product precipitates out, filter with suction, and wash the crude product with ethanol to obtain the pure product 2-amino-3-(1H-benzo[d]imidazole)-4-(4-methoxy phenyl)-7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-one, the structural formula is as follows:
[0041]
[0042] Yield: 56%; Pale yellow solid; H NMR spectrum (DMSO-d 6, 400MHz) (δ, ppm): 11.76(s, 1H), 7.80(s, 2H), 7.41(d, J=7.2Hz, 1H), 7.33-7.31(m, 3H), 7.05-7.00(m, 2H), 6.75(d, J=8.4Hz, 2H), 4.93(s, 1H), 3.63(s, 3H), 2.58(d, J=17.6Hz, 1H), 2.46(d, J=17.6Hz, 1H), 2.32(d, J=16.0Hz, 1H), 2.10(...
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