Process for the preparation of new methylamine derivatives

The methylamine derivatives of general formula: and their non-toxic addition salts, in which R represents n-propyl, isopropyl, isobutyl or allyl, R1 represents hydrogen, methyl or propargyl and R2 represents methyl or propargyl, are obtained by heating an amine, which is unsubstituted or R1-substituted on the nitrogen, with a methyl or propargyl halide in the presence of an alkaline agent to produce a basic methylamine derivative which is reacted with an acid to produce a non-toxic addition salt. The methylamine derivatives in question are useful in human or veterinary medicine as antiparkinsonian agents or correctors of extrapyramidal disorders due to neuroleptics. They are less inhibiting of monoamine oxidase than the corresponding derivatives which are unsubstituted on the nitrogen and have, for this reason, fewer side effects.