Patent ID: 7446203

Claim:
A process for the preparation of the compound of the general formula I or a salt thereof: wherein R represents, the same as or different from each other, a hydrogen atom or a lower alkoxy group, n represents an integer of 1 to 4 and Y represents H or F, which comprises hydrogenating the compound of the general formula II: wherein R, n and Y have the same meaning as defined above, with hydrogen using platinum oxide, palladium-carbon, raney nickel or ruthenium oxide catalyst in a solvent selected from the group consisting of alcohols, methanol, ethanol, acetonitrile, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, dioxane, aromatic hydrocarbons, benzene, toluene, xylene, halogenated hydrocarbons, dichloromethane, chloroform, carbontetrachloride, ketones, acetone, methyl ethyl ketone, ethyl isobutyl ketone, ethers, tert-butyl methyl ether, carboxylates, ethyl acetate, and mixtures thereof, in the presence of an acid in the quantities ranging from 0.1 to 10 moles of the acid per mole of the compound of formula II, under a hydrogen pressure of 1 to 10 bars and optionally converting the compound of the formula I to the salt.