Patent ID: 7547789

Claim:
A process for the preparation of an N-(4-piperidinyl)-N-ethyl-phenylacetamide of formula (I): wherein R 1 is S(O) 2 (C 1-4 alkyl), and R 2 is hydrogen, halogen, C 1-4 alkyl, C 1-4 alkoxy, cyano or S(O) 2 (C 1-4 alkyl); the process comprising the steps of: a. hydrogenating a mixture of ethylamine and a compound of formula (II) (1-tert-butoxycarbonyl-4-piperidone): in a solvent comprising ethanol, in the presence of a suitable palladium or platinum catalyst, at a pressure in the range 1-5 bar and at a temperature in the range 10-80° C., to form a compound of formula (III) (1-tert-butoxycarbonyl-4-(N-ethylamino)piperidine): b. reacting a compound of formula (IV): with carbonyldiimidazole in an ether or an aromatic solvent, at a temperature in the range 10-80° C.; and reacting the product so formed with the compound of formula (III) at a temperature in the range 10-80° C. in a suitable solvent, to form a compound of formula (V): and, c. forming a compound of formula (I) by treating a compound of formula (V) with HCl in a suitable solvent, at a temperature in the range 10-80° C.