p-Toluenesulfonic acid → 3-(1H-1,3-benzodiazol-2-yl)propan-1-amine

Participants

Reaction Steps

162 g (1.5 mols) of o-phenylene diamine, 85 g (1 mol) of pyrrolidone and 8 g of p-toluene sulphonic acid are melted, while stirring, in a nitrogen atmosphere and the water which is gradually eliminated is distilled off over a period of 5 hours at a sump temperature of 150° to 250°C. The reaction mixture is then subjected to fractional distillation under reduced pressure. 150 g (85.5 % of the theoretical) of 2-(3'-aminopropyl)-benzimidazole are obtained at a pressure of 0.1 Torr and a boiling temperature of 190° to 196°C in the form of a brownish-yellow crystalline mass melting at 118°C.

Provenance & Evidence