Promethazine Hydrochloride → Thiazinamium Metilsulfate

Participants

Reaction Steps

dl-Promethazine hydrochloride (30 g.) was converted to the free base and was dissolved in absolute acetone and dimethyl sulfate (10 g.) was added (this is less than are equivalent of dimethyl sulfate due to its hazardous nature). After standing overnight, the solution was heated on a steam bath and cooled. The precipitated solid was filtered, washed with tetrahydrofuran and ether to provide dl-trimethyl[1-methyl-2-(phenothiazine-10-yl)ethyl]ammonium methyl sulfate, 27.6 g., m.p. 170°-173° C.

Provenance & Evidence