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., an the mixture is left stirring for a further 1 hour 15 minutes until gaseous evolution has ceased. The fine suspension obtained is introduced with stirring in the course of 4 hours 30 minutes and at a temperature in the region of 25° C. into a solution of ethyl (2RS)-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 the whole is thereafter poured onto 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 khaki crystals, m.p. 117°-118° C., which are used without further treatment in the next step.

Provenance & Evidence