Patent ID: 11505549

Abstract:
A novel process for preparation of Deutetrabenazine ((RR, SS)-1,3,4,6,7-11b-Hexahydro-9,10-di(methoxy-d6)-3-(2-methylpropyl)-2H-benzo [a] quinolizin-2-one) of formula I comprises of methylation of N-(2-(3,4-dihydroxy-phenyl)-ethyl)-formamide compound of formula III with deuteriated methanol (CD3OD or CD3OH) to obtain d6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide compound of formula IV; cyclization of d6-N-(2-(3,4-dimethoxy-phenyl)-ethyl)-formamide in presences of dehydrating agent to obtain d6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V; reacting d6-6,7-Dimethoxy-3,4-dihydroisoquinoline compound of formula V with 2-acetyl-N,N,N,4-tetramethyl-1-pentanaminium iodide compound of formula VI.