Patent ID: 7074935

Claim:
A process for preparing alfentanil, the process comprising: (a) reacting a piperidone compound having the formula with chloroform to form a 4-dichloroepoxy-piperidine intermediate compound, said intermediate compound being reacted with aniline to form a 4-amino-4-carboxyamino-piperidine compound having the formula (b) alkylating the 4-amino-4-carboxyamino-piperidine compound to form an alkylated 4-amino-4-carboxyamino-piperidine compound having the formula (c) hydrolyzing the ester group of the alkylated 4-amino-4-carboxyamino-piperidine compound to form a piperidine hydrolysis product having the formula (d) treating said piperidine hydrolysis product with a hydride to produce a 4-hydroxymethyl-piperidine having the structure (e) reacting said 4-hydroxymethyl-piperidine with a haloalkyl-tetrazole so as to form an N-substituted tetrazole-piperidine product having the structure (f) etherifying said N-substituted tetrazole-piperidine product to form an alkoxymethyl-N-substituted tetrazole-piperidine product having the structure (g) acylating the alkoxymethyl-N-substituted tetrazole-piperidine product to form an acylated alkoxymethyl-N-substituted tetrazole-piperidine product, alfentanil, having the structure wherein n is an integer from 0 to about 10 and R is C 1-6 alkyl.