process for the production of yohimbanderivaten

摘要

The invention comprises 17-oxo-yohimbane derivatives having in the 18-position of ring E a substituted methylene group of the formula =CYH wherein Y is OH, OR, OOC.R, OOC.Aryl, SR or a group of the formula =CH.NHR2 or =CH.NR3R4, wherein R is an alkyl group of 1-6 carbon atoms, "Aryl" is a phenyl or naphthyl radical, R2 is an alkyl group of 1-6 carbon atoms or a phenyl or naphthyl group and R3 and R4 are alkyl groups of 1-6 carbon atoms or together with the nitrogen atom form a heterocyclic group, and pharmaceutically acceptable salts thereof. It comprises also the preparation of these compounds by (a) Claisen condensation of a yohimban - 17 - one with a C1-6 alkyl formate to give an 18-hydroxymethylene-yohimban-17-one (Y=OH); (b) if desired, reacting the product with an alkanol, alkyl mercaptan, amine or acylating agent to form a compound wherein Y is OR,SR, NHR2, NR3R4, OOC.R or OOC.Aryl and (c) if desired, forming an acid add.tion salt. Examples describe the preparation of yohimbane derivatives as defined above wherein Y is OH, benzoyloxy, isobutoxy, isobutylamino, anilino, butylthio, and pyrrolidino.