1-p-chlorobenzoyl-2-methyl-5-methoxy or dimethylamino-3

Prepn. of 5-methoxy- and 5-dimethylamino-1-p-chloro benzoyl 2-methyl 3-indolylacetic acids (I) R = methoxy- or dimethylamino. A soln. of 1-p-chlorobenzoyl 5-methoxy 3-indolyl acetic acid in dichloroethane is added to a mixture of dry aluminium chloride in dichloroethane. A cold soln. of methyl chloride in dichloroethane is added and the reaction allowed to continue until evolution of HCl has ceased. The reaction mixture is poured onto ice, the organic phase separated and washed with water. The solvent is removed under reduced pressure thus yielding 1-p-chlorobenzoyl 2-methyl 5-methoxy 3-indolyl acetic acid which is recrystallised from t-butanol.