Patent ID: 7473778
Filing Date: 2009-01-06
Classification: A61P,C07D

Abstract:
1. A process for preparing the compound of formula I wherein (a) 2-nitrophenylacetic acid is reacted with 4-amino-N-phenylmethylpiperidine to form 2-nitro-N-[1-(phenylmethyl)-4-piperidinyl]-phenylacetamide of formula II (b) the nitro group of the 2-nitro-N-[1-(phenylmethyl)-4-piperidinyl]-phenylacetamide of formula II obtained is hydrogenated to form the amino group, thereby producing the compound of formula III (c) the intermediate product of formula III obtained is reacted by the addition of an ester and in the presence of a base to form a carbamate of general formula IV wherein R 1 denotes a phenyl, benzyl, allyl, 2,2,2-trichloroethyl or a straight-chain or branched C 1-6 -alkyl group, and (d) the compound of general formula IV obtained is dissolved in an aprotic organic solvent, the carbonyl group is converted into a methylene group by the addition of a reducing agent and cyclised to form 3-[1-(phenylmethyl)-4-piperidinyl]-2,3,4,5-tetrahydro-1,3-benzodiazepin-2(1H)-one of formula V