CAS NO:58-33-3 Promethazine hydrochloride Name Promethazine hydrochloride Synonyms 10-(2-Dimethylamino-1-propyl)phenothiazine hydrochloride Molecular Formula C17H20N2S.HCl Molecular Weight 320.88 CAS Registry Number 58-33-3 widelychemical EINECS 200-375-2 Uses: for allergic diseases and vomiting during pregnancy Melting point 230-232 oC Appearance: White or light yellow crystalline powder PH: 4.0-5.0 Loss on drying: not more than 0.5% Residue on ignition: not more than 0.1% Assay: not less than 99.0%