Acetic Anhydride → 7-(3-Acetamidophenyl)-1-phenyl-5-trifluoromethylbenzimidazole

Reaction equation

[NH2:1][C:2]1[CH:3]=[C:4]([C:8]2[C:13]3[N:14]([C:17]4[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=4)[CH:15]=[N:16][C:12]=3[CH:11]=[C:10]([C:23]([F:26])([F:25])[F:24])[CH:9]=2)[CH:5]=[CH:6][CH:7]=1.C(=O)([O-])[O-].[Na+].[Na+].[C:33](OC(=O)C)(=[O:35])[CH3:34]>>[C:33]([NH:1][C:2]1[CH:3]=[C:4]([C:8]2[C:13]3[N:14]([C:17]4[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=4)[CH:15]=[N:16][C:12]=3[CH:11]=[C:10]([C:23]([F:26])([F:25])[F:24])[CH:9]=2)[CH:5]=[CH:6][CH:7]=1)(=[O:35])[CH3:34]

Participants

Reactant 3

HCID 7918Acetic Anhydride

HCID 10340Sodium Carbonate

HCID 114623287-(3-Aminophenyl)-1-phenyl-5-trifluoromethylbenzimidazole

Product 1

HCID 114067807-(3-Acetamidophenyl)-1-phenyl-5-trifluoromethylbenzimidazoleYield 76%

Procedure

A solution of 7-(3-aminophenyl)-1-phenyl-5-trifluoromethylbenzimidazole (0.32 g, 0.9 mmol) in acetic anhydride (3 ml) was stirred at ambient temperature for one hour. Saturated, aqueous sodium carbonate was added and the resultant mixture was extracted with ethyl acetate. This organic extract was washed with water and brine, successively, dried over magnesium sulphate, concentrated under reduced pressure and purified by column chromatography on silica gel eluting with a mixture of dichloromethane and methanol (97:3, v/v) to afford the desired product (0.27 g, 76%) m/z, 396.1 (M+H)+.