PROCESS FOR THE PREPARATION OF N-METHYL DERIVATIVES OF ERGOLINE

摘要

A process for preparing an N-methyl derivative of ergoline of formula: in which R1 denotes a carboxy or alkoxycarbonyl group in which the alkyl portion contains 1 to 4 carbon atoms, R2 denotes a hydrogen atom or a methoxy group and R3 denotes a hydrogen atom or R2 and R3 together form a direct bond, or in which R1 denotes a hydroxymethyl group, R2 denotes a hydrogen atom or a methoxy group and R3 denotes a hydrogen atom, which comprises methylating an ergoline derivative of formula: in which R1, R2 and R3 are defined as above, with methyl carbonate in the presence of a basic agent, in an apolar aprotic solvent in the present of a phase transfer catalyst.