GB999393A - New ethers of the yohimbane series and process for their manufacture - Google Patents

Abstract

The invention comprises compounds of the general formula <FORM:0999393/C2/1> (wherein R1 and R3 each represent an unsubstituted or substituted aliphatic hydrocarbon group, R2 represents a C1- 4 alkoxy group, R4, R5 and R6 each represent a hydrogen or halogen atom or a C1- 4 alkyl, alkoxy or alkylmercapto group, or two of them in adjacent positions together represent an alkylenedioxy group of 1 or 2 carbon atoms, and R7 represents a hydrogen atom or a C1- 4 alkyl group) and their N-oxides, and salts of these compounds, but excluding methyl 18-epi-O-alkylreserpates and their salts in which the 18-O-alkyl group contains less than 4 carbon atoms, and the preparation of the foregoing compounds by subjecting a compound of the general formula <FORM:0999393/C2/2> (wherein R1 represents the acyl radical of an organic sulphonic acid), or an N-oxide thereof or a salt of these compounds, to alcoholysis with an aliphatic alcohol, and, if desired or necessary, converting a resulting tertiary amine into an N-oxide or vice versa and/or a resulting base into a salt thereof or vice versa, and/or esterifying a free hydroxy group, if present (in R1 or R3), by the action of a reactive, functionally converted carboxylic acid derivative. Sulphonic esters of the second general formula above are prepared by reacting the corresponding 18b -hydroxy compounds with organic sulphonic acid halides in the presence of a tertiary organic nitrogen base. Pharmaceutical and veterinary preparations comprise the compounds of the invention, which are sedatives, tranquillizers, antihypertensive and antifibrillatory agents and/or local anaesthetics, together with a carrier suitable for pharmaceutical or veterinary use. They may be in forms suitable for enteral or parenteral administration, e.g. tablets, dragees, capsules, solutions, suspensions or emulsions, or animal feedstuffs. Salts specified include those with ascorbic, salicylic and p-aminosalicylic acids, methionine, tryptophan, lysine and arginine. Specifications 999,392, 999,394 and 999,399 are referred to.