A process for the preparation on N-methyl-aryloxy-propanamine derivatives of the formula I and salts thereof. The invention also relates to the preparation and use novel intermediate of the formula XII. The invention also relates to the process of further conversion of novel intermediate into N-methyl-aryloxy propanamine derivatives and salts thereof.Wherein Q and P independently represents substituted or unsubstituted aryl group such as phenyl, naphthyl, pyridine, furanyl, pyranyl thienyl, and the like optionally substituted aryl by a halogen, a straight chain or branched alkyl group containing 1 to 6 carbon atoms, —O-alkyl group containing straight chain or branched C1-C6 alkyl group, an alkoxy group containing a straight chain or branched alkyl group having 1 to 6 carbon atoms, which comprises demethylation of N,N-dimethyl analogues of compound of formula IA.