Eburnamenine derivatives, pharmaceutical compositions and methods employing them and processes for their preparation

摘要

The invention relates to the preparation of cis and trans stereoisomers of racemic and optically active eburnamenine derivatives of the general formula (Ia) <IMAGE> (Ia) or (Ib), <IMAGE> (Ib) wherein R1 stands for a C1-4 alkyl group; and R stands for hydrogen, a C1-6 alkyl group, a C2-6 alkenyl group, an acyl or substituted acyl group, as well as their acid addition salts, of which the trans compounds are novel. The invention also relates to the compounds of the general formula (IIIa) <IMAGE> (IIIa) and (IIIb), <IMAGE> (IIIb) wherein R1 and R' represent a C1-4 alkyl group. The compounds of the general formulae (Ia) and (Ib) possess a vasodilatory effect which is substantially higher than that of pentoxifyllin, a known peripheral vasodilator.