Method for the production of high-purity 4a, 5, 9, 10, 11, 12,-hexahydro-6H-benzofuro [3a, 3, 2-ef] [2] benzazepine, and the derivatives thereof

摘要

A process for the production of extremely pure galanthamine and galanthamine derivatives is provided. Racemic bromine narwedine is debrominated under palladium catalysis. The reaction mixture is then worked-up in the presence of oxygen or peroxides so that the palladium catalyst is converted into an insoluble form that can be easily separated. Further reaction is carried out by reduction of enantiomerically pure narwedine to form enantiomerically pure galanthamine, which is then alkylated or dealkylated, so that a corresponding substitution on the ring-nitrogen atom is achieved. By further purification, such as recrystallization, residual portions of palladium of below 5 ppm are achieved. The pure galanthamine can then be directly used as a pharmaceutical raw material.