PROCESS FOR THE PREPARATION OF DONEPEZIL INTERMEDIATE
摘要
<p>This invention relates to a process for the preparation of N-benzyl-4- formylpiperidine (I), a key intermediate used in the synthesis Donepezil. The said process comprises the decomposition of sulfoxonium complex of formula (V) in the presence of base. The compound of formula (V) may be prepared by a method comprising reacting N-Benzyl-4-hydroxymethylpiperidine (II) with dimethylsulfide and N-chlorosuccinamide; or dimethylsulfide and N-bromosuccinamide; or dimethylsulfide and chlorine gas; or thioanisole and N-chlorosuccinamide; or thioanisole and N-bromosuccinamide in a suitable organic solvent.</p>
