Patent ID: 7053218

Claim:
A process for regioselective demethylation of a compound of general formula 1 Wherein, R 1 =H/OMe X=aryloxy/aryl/Yohimban moiety of reserpine/their derivatives. to obtain a compound of general formula 2, Wherein, R 1 =H/OMe X=aryloxy/aryl/Yohimban moiety of reserpine/their derivatives. said process comprises steps: (a) mixing compound of formula 1 with an organic solvent; (b) adding Lewis acid to mixture of step (a) and stirring the reaction mixture at a temperature in the range of 0 to 80° C. for a time period in the range of 5 minutes to 3 hours; and (c) adding mineral acid into the reaction mixture of step (b), further stirring the mixture for a time period in the range of 2 to 10 minutes to obtain a demethylated compound of general formula 2.