Acetic Acid → 4-Chloro-6,7,8-trifluorocarbostyril

Participants

Reaction Conditions

Reaction Steps

A suspension of 4-chloro-2-ethoxy-6,7,8-trifluoroquinoline (70.4 g) in 35% strength aqueous hydrochloric acid solution (170 cc), acetic acid (420 cc) and water (250 cc) is heated with stirring to a temperature in the region of 100° C. for 2 hours and a half. After cooling to approximately 20° C., the reaction mixture is poured into water (1100 cc) at approximately 5° C. and stirred for 15 minutes at this temperature and the insoluble matter is then drained and washed with water (3×220 cc). 4-Chloro-6,7,8-trifluorocarbostyril (61 g) is obtained in the form of a cream-colored solid, m.p. 213° C., which is used without further purification for the subsequent steps.

Provenance & Evidence