Benzimidazole → Ethyl 2-(1H-benzimidazol-1yl)-4-(trifluoromethyl)5-oxazolecarboxylate

Participants

Reaction Steps

A reaction vessel was charged with 5 g (21 mmol) ethyl 2-chloro-4-trifluoromethyl-5-oxazolecarboxylate and 4.96 g (42 mmol) benzimidazole. This mixture without solvent was heated at a temperature of about 100°-110° C. for 30 hours. The mixture was cooled to room temperature. This mixture was slurried in ethyl ether, washed with 5% hydrochloric acid, and then washed with large amounts of water, at which time a white precipitate began to form. A yellow filtrate was separated from 2.1 g of the precipitate (m.p. 133°-135° C.). The filtrate was concentrated under reduced pressure to provide 2.80 g of an off-white solid material (m.p. 132°-134° C.). This solid material and the white precipitate were combined and recrystallized from ethanol-water solution to give 4.03 g of an off-white solid product (m.p. 132°-134° C.) identified in Table I.

Provenance & Evidence