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 poured into a suspension of sodium hydride (24 g) in dimethylformamide (1 liter) at a temperature of about 25° C., whilst stirring and in 2 hours 30 minutes, then the mixture is stirred for a further 1 hour 15 minutes until evolution of gas has ended. The fine suspension obtained is poured, with stirring and at a temperature of about 25° C., in 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 then the whole is poured onto a mixture of ice (2 kg) in distilled water (4 liters): a gum precipitates and then crystallizes. The solid formed is centrifuged, washed successively with distilled water (6×500 cc) and petroleum ether (2×500 cc) and dried in air. Ethyl (2RS)-2-(2-cyano-10-phenothiazinyl)propionate (296.5 g) is thus obtained in the form of khaki-colored crystals which melt at 117°-8° C., used as such in the following stage.

Provenance & Evidence