Ethanol → ethyl (2RS)-2-(2-cyano-10-phenothiazinyl)propionate

Participants

Reaction Steps

A solution of 2-phenothiazinecarbonitrile (224.5 g) in dimethylformamide (1 liter) is introduced, with stirring and in the course of 2 hours 30 minutes, into a suspension of sodium hydride (24 g) in dimethylformamide (1 liter) at a temperature in the region of 25° C., and the mixture is left stirred for a further 1 hour 15 minutes until the evolution of gas has ceased. The fine suspension obtained is introduced, with stirring and at a temperature in the region of 25° C., in the course of 4 hours 30 minutes, into a solution of ethyl 2-chloropropionate (255 cc) in dimethylformamide (1 liter), and stirring is continued for 16 hours. Ethanol (100 cc) is then poured into the reaction mixture, and thereafter the whole is poured into a mixture of ice (2 kg) in distilled water (4 liters): a gum precipitates and then crystallizes. The solid formed is drained, washed successively with distilled water (6×500 cc) and petroleum ether (2× 500 cc) and dried in the air. Ethyl (2RS)-2-(2-cyano-10-phenothiazinyl)propionate (296.5 g) is thereby obtained in the form of yellowish brown crystals, m.p. 117°-8° C., which are used as they are in the next stage.

Provenance & Evidence