Industrially scalable synthesis of anti-alzheimer drug donepezil

This paper describes a simple, efficient and industrially scalable total synthesis of donepezil hydrochloride. The article also reported the X-ray studies of the 2-(1-benzylpiperidin-4-ylmethyliden)-5,6-dimethoxyindan-1-one, an intermediate in the synthesis of donepezil. The crystal structure analysis of 2-(1-benzylpiperidin-4-ylmethyliden)-5,6-dimethoxyindan-1-one shows that it crystallizes in monoclinic class under the space group P121/c1 with cell parameters, a = 17.2992(7) Å, b = 10.1999(4) Å, c = 11.9539(5) Å, β = 103.450(2)°, V = 2051.42(15) ų and Z = 4.