Preparation of pure cis-Tramadol hydrochloride

摘要

Cis-Tramadol hydrochloride is prepared by forming a Mannich hydrochloride, liberating the Mannich base, reacting the Mannich base with a Grignard reagent to form a base hydrate of cis-Tramadol which is used to form pure cis-Tramadol hydrochloride. Also claimed is the base hydrate of cis-Tramadol per se and its use as a medicament.