Patent ID: 7378439

Claim:
A process for preparation of compound of structural formula (I) and its acid addition salts, particularly hydrochloride salt, which comprises the steps of: a) Condensing a compound of formula II wherein X is a leaving group, with alkali metal salt of an imide in a solvent to form compound of formula III b) Treating compound of formula III with nitromethane in presence of RCOOH, R 1 NH 2 and HC(OR 2 ) 3 in a polar solvent to form a compound of formula IV, and wherein R is C 1-4 alkyl preferably methyl, R 1 is C 1-4 alkyl preferably butyl, R 2 is C 1-4 alkyl preferably methyl, c) Treating compound of formula IV with FeCl3 and R 3 COCl, in solvent to form compound of formula V, wherein R 3 is C 1-4 alkyl preferably butyl, d) Treating compound of formula V with a hydrogen donor in presence of reduction catalyst in ethyl acetate, to form a compound of formula VI, e) Treating compound of formula VI with hydrazine hydrate or alkali metal hydroxide followed by aqueous halo acid to form a compound of formula VII, f) Treating compound VII with propionaldehyde under reducing conditions in presence of a reduction catalyst in solvent to form a compound of formula (I), g) Conversion of compound of formula I to its hydrochloride salt, h) Purification of hydrochloride salt of compound of formula I.