Potassium Carbonate → Benzimidazole

Participants

Reaction Steps

1.8 Grams of a 2-cyanobenzimidazole compound [compound (iii)] of the formula (II) in which X is Br and Z is OCF2CFHO was dissolved in 70 ml of acetonitrile. 1.5 Grams of potassium carbonate was added thereto. The resulting mixture was heated under reflux for 20 minutes. Thereafter, 1.2 g of dimethylsulfamoyl chloride was added thereto. Refluxing was continued for 1 hour with heating. The reaction solution was poured into ice water and extracted with ethyl acetate. The organic layer was washed with water, dried over anhydrous sodium sulfate and concentrated. Column chromatographying the resulting residue on silica gel with chloroform as an eluent and recrystallizing it from hexane/ethyl acetate gave 1.18 g of a benzimidazole derivative [present compound (3)]of the formula (I) in which X is Br, Z is OCF2CFHO, R is CN and Q is N(CH3)2.

Provenance & Evidence