Patent ID: 6531597
Filing Date: 2003-03-11
Classification: C07C,C07D

Abstract:
A process for the preparation of a compound of formula whereinR2a, R2b are each independently selected from the group consisting of hydrogen, halogen, lower alkoxy, cyano, â€”COOH, lower alkoxy carbonyl, lower alkyl and lower alkyl substituted by halogen; R3a, R3b are each independently selected from the group consisting of hydrogen, lower alkyl and lower cycloalkyl, or alternatively, R3a and R3b together are, â€”(CH2)nâ€” wherein n=2,3 or 5; comprising a) reacting a Grignard derivative of a compound of formula â€ƒwherein X is Cl, Br or I, with a compound of formula â€ƒforming a compound of formula b) carbonylating the compound of formula IX by reacting compound IX in a carbonylation mixture in the presence of a reagent consisting essentially of a sufficient quantity of a strong acid thereby forming the compound of formula I.