A NOVEL SYNTHESIS OF PROCAINAMIDE HYDROCHLORIDE

A new route for procainamide synthesis was investigated for industrial production by direct condensation of p-aminobenzoic acid with diethylaminoethylamine in the absence of solvent and any activating or dehydrating agent. The procainamide thus obtained had a high purity and a boiling point of 240℃/2mm. The yield of the distilled base was 65% of the theory.The crude or distilled procainamide formed a hydrate containing one molecule of water, mp 51.5～52℃, from which most impurities and coloring matters could be washed away, thus greatly facilitated the purification of the hydrochloride prepared later.The hydrochloride was performed in water solution. After concentrating under dimi nished pressure at 120～140℃, the melt was poured into absolute alcohol for crystallization and decoloration. The product thus obtained agreed with the requirements of pharmacopoea and was suitable for intravenous use. The mp after recrystallizing twice from absolute alcohol was 168～170℃.