Methyl chloroformate → 4-chloro-3-isobutyryloxy-10H-phenothiazine

Participants

Reaction Conditions

Reaction Steps

To a solution of iso-butyric acid (1.6 ml) in THF (10 ml) at 0° C. was added Et3N (2.7 ml) and methylchloroformate (1.5 ml). To this resulting suspension was added slowly at 0° C. a solution of 4-chloro-3-hydroxy-10H-phenothiazine in THF (10 ml). The reaction mixture was stirred at 5° C. for 12 hours, after which H2O was added and the resulting aqueous phase extracted with ethyl acetate. The organic layer was then dried and evaporated. The resulting residue was purified by chromatography on silica gel to give 2.25 g of 4-chloro-3-isobutyryloxy-10H-phenothiazine (m.p. 155° C.).

Provenance & Evidence