2-(1H-benzimidazol-2-yl)isoindole-1,3-dione → N-(benzimidazol-2-yl)-2-(n-butoxycarbonyl)-benzamide

Participants

Reaction Steps

N-(Benzimidazol-2-yl)phthalimide (4 g.) in 200 ml. of n-butyl alcohol is heated at 115° C. for 35 minutes. On cooling, colorless needles form. These are removed by suction filtration, washed with butyl alcohol and finally with diethyl ether. After drying for three hours at 125° C. under vacuum, a yield of 2.5 g. of N-(benzimidazol-2-yl)-2-(n-butoxycarbonyl)-benzamide, m.p. 187° C., is obtained. Additional heating to higher temperatures causes a reclosure to the phthalimide and remelting which corresponds to the phthalimide, m.p. 267°-268° C.

Provenance & Evidence