GB811827A - Reserpic acid derivative - Google Patents

Abstract

The invention comprises dihydrorescinnamine, C35H44N2O9, and non-toxic salts thereof, together with processes for its preparation (a) by catalytic hydrogenation of rescinnamine, (b) by esterification of methyl reserpate with a dihydro-3,4,5-trimethoxycinnamic acid derivative, particularly the acid chloride. The hydrogenation is preferably carried out with noble metal catalysts at ordinary temperature or with Raney nickel at elevated temperature, optionally under pressure. Specified non-toxic salts are the hydrochloride, sulphate, hydrobromide, citrate, tartrate and oxalate. In examples: (1) rescinnamine is hydrogenated in acetic acid over platinum oxide at 5 atmospheres excess pressure and the dihydrorescinnamine crystallized from methanol or isopropanol; (2) and (4) as in (1), but using Raney nickel in methanol and ethanol respectively to yield dihydrorescinnamine; (3) methyl reserpate in pyridine is treated with 3,4,5-trimethoxyphenylpropionyl chloride and the product chromatographed on alumina to give dihydrorescinnamine. 3,4,5 - Trimethoxyphenylpropionyl chloride is prepared from trimethoxycinnamic acid by hydrogenation and then reaction with thionyl chloride.ALSO:Pharmaceutical compositions having high hypotensive action comprise dihydrorescinnamine or a non-toxic acid addition salt thereof in admixture with a pharmaceutical solid or parenterally acceptable diluent or carrier. Solutions in weakly acidulated water, e.g. containing acetic, formic or tartaric acid, are stable and the drug may be administered by injection or orally, the active dose being from 0.25-0.75 mg.