Acetic Acid → Tizanidine hydrochloride

Participants

Reaction Conditions

Reaction Steps

12.0 g of the tizanidine base (99.15% HPLC) are added to 26 ml of acetic acid. The resulting suspension is dissolved under stirring and heating at ca. 70 to 80° C. 55 ml of acetone and 1 g of active coal are added to this solution and after stirring for 15 minutes the solution is filtered. The hot filtrate is acidified by addition of 10 ml of isopropanolic hydrogen chloride. Shortly thereafter quick crystallization of tizanidine hydrochloride occurs, which is completed by cooling to 0 to 5° C. After aspiration 13.0 g of tizanidine hydrochloride (i.e. 95.0% th.) are obtained, purity 99.95% HPLC, colour GY6.

Provenance & Evidence