| 摘要 |
The invention relates to a new process for preparing derivatives of the formula I <IMAGE> in which: - R1 denotes a hydrogen atom, an alkyl radical, an alkylene radical, an arylalkyl radical optionally substituted on the aromatic ring by a halogen atom, a hydroxyl radical or an alkyl or alkoxy radical, a 2-indolylmethyl radical, a 4-imidazolylmethyl radical or an alkoxycarbonylmethyl radical, and - each of R2 and R3, which are identical or different, denotes an alkyl radical, characterised in that vinblastinoic acid is condensed with N,N'-carbonyldiimidazole at room temperature in an anhydrous polar solvent under inert atmosphere and in that an aminophosphonate of the following formula: <IMAGE> in which R1, R2 and R3 have the same meaning as that shown in formula I is then reacted in the reaction medium and in that the medium is next hydrolysed with water and the expected compounds are extracted with the aid of a chlorinated hydrocarbon. |
