反应详情

Oxylyl chloride (0.437 g) is added to a methylene chloride (8 ml) solution of 6-carboxy-1-(2,4-dichlorobenzyl)-2-methylbenzimidazole (0.490 g) and N,N-dimethylformamide (1 drop) under ice-chilled conditions, and the solution is stirred for 1.5 hours at room temperature. Then, 28% aqueous ammonia (4 ml) is added and the solution is stirred for 12 hours at room temperature. Water and methylene chloride are added to the reaction solution for extraction. After the organic layer is concentrated, precipitated crystals are collected, dried and 6-carbamoyl-1-(2,4-dichlorobenzyl)-2-methylbenzimidazole (0.240 g) is obtained. 1H-NMR (DMSO-d6, δ): 2.48 (3H, s), 5.54 (2H, s), 6.41 (1H, d, J=8.4 Hz), 7.21-8.02 (3H, m), 7.31 (1H, dd, J=2.2 and 8.4 Hz), 7.60 (1H, d, J=8.4 Hz), 7.75 (1H, m), 7.93 (1H, s).

1. temperaturechilled conditions
2. stirringthe solution is stirred for 12 hours at room temperature
3. concentrationAfter the organic layer is concentrated
4. customprecipitated crystals
5. customare collected
6. customdried