Intermediates for synthesis of vinblastine, process for preparation of the intermediates and process for synthesis of vinblastines

摘要

An intermediate for vinblastine synthesis represented by general formula A. general formula A. (in the formula, R₁, R₂, R₃ and R₄ are the group selected independently from the group consisting of H, lower alkyl group, lower alkoxy group, halogen, lower perfluoroalkyl group, lower alkylthio group, hydroxy group, amino group, mono- or di-alkyl or acylamino group, lower alkyl or arylsulfonyloxy group. R₅ is H, or a lower alkyl group or a substituted or non-substituted aryl group, R₆ is an alkyl group of carbon number 4 or less, R₇ is a substituted or non-substituted aryl group, R₈ is a substituted or non-substituted aryl group or lower alkyl group and R₉ is an acyl group or trialkylsilyl group.) A method for synthesis of the compound of general formula A utilizing radical ring forming reaction of thioanilides and using the compound of general formula B as the starting material, synthesizing thioanilide of general formula C by the reaction with compound 1 and the formation of a 11-membered ring by intramolecular alkylation of 2-nitrobenzenesulfonamide by which the reactions can proceed under mild conditions and high yield can be accomplished.