METHOD OF OBTAINING AMLODIPINE BESYLATE

摘要

The invention relates to a simple, cost-effective and easily-industrially-scalable method of obtaining a pharmaceutical-grade product in a high yield, which is based on reacting a phthalimide/amlodipine derivative with a deprotective agent in the presence of an inert solvent, such as a mixture of toluene and isopropanol, in order to form amlodipine with the addition of benzenesulphonic acid. The crude amlodipine benzenesulphonate obtained can be recrystallised in order to obtain a solid crystalline product of pharmaceutical grade in a high recrystallisation yield of above 95 %.