Patent ID: 6579984
Filing Date: 2003-06-17
Classification: C07C,C07D

Abstract:
A process for the preparation of a compound of the formula: In whichR is hydrogen or a group of the formula â€”SO2R1; R1 is C1-6-alkyl; R2 is hydrogen or C1-6-alkyl; R3 is C1-6-alkyl; and R4 is C1-6-alkyl, comprising in a first stage, reacting a compound of the formula: in which R3 and R4 have the above-mentioned meanings, in the presence of a Lewis acid with 4-fluorobenzonitrile to give a compound of the formula: in which R3 and R4 have the above-mentioned meaning, and, in a second stage, reacting the compound of the formula III with a compound of the formula: in which R and R2 have the above-mentioned meanings, to give the final product of the formula I.