Cyanogen Bromide → 2-Amino-5-(4-fluorophenylsulfonyloxy)benzimidazole

Participants

Reaction Steps

14.1 g of 1,2-diamino-4-(4-fluorophenylsulfonyloxy)benzene (see Example 1) and 5.8 g of cyanogen bromide in 150 ml of methanol are heated to reflux for 6 h, then the mixture is cooled and concentrated. The residue is dissolved in water, and ammonia is added with cooling. The precipitated 2-aminobenzimidazole derivative is filtered off with suction, washed with water, dried and recrystallized from ethyl acetate and diisopropyl ether, with the addition of active charcoal; melting point 192° C.

Provenance & Evidence