Patent ID: 6258956
Filing Date: 2001-07-10
Classification: C07B,C07C

Abstract:
A process for preparing a compound of the formula I ##STR17##wherein R.sup.1 is aryl, heteroaryl, substituted aryl or substituted heteroaryl and R.sup.2 is hydrogen, alkyl or aralkyl, or a salt thereof,comprising reacting a compound of the formula II ##STR18##wherein R.sup.1 is as described above and R2 is alkyl or aralkyl, with a compound of the formula III ##STR19##wherein R5 is hydrogen or alkoxy,under conditions of reduced pressure, such that the reaction solution boils at temperatures of between about 40.degree. and about 65.degree. C., in an inert solvent, which solvent under reduced pressure is capable of azeotropic removal of water, to form the compound of formula IV, ##STR20##reacting the compound of formula IV with hydrogen gas in the presence of a palladium catalyst to form the compound of formula V ##STR21##and reacting the compound of formula V to form the compound of formula I.