PROCESS FOR PREPARING ALKOXYALKYL-IDENEHYDRAZINOPYRIDAZINE DERIVATIVES

摘要

A process for preparing a compound of the formula (4): is described wherein R<3> and R<4> are both hydrogen or together are =CR<1>R<2>, where R<1> is hydrogen or C1-3alkyl and R<2> is C1-3alkyl, carboxy or phenyl, which comprises reducing a compound of the formula (5) : wherein Ph is phenyl, X is WN or O wherein W is 3,4-di(MeO)Ph(CH2)2-; Y and Z are both hydrogen or together are a protecting group and thereafter : i) removing the triphenylmethyl group and any other protecting groups; ii) when X is WN optionally reacting with R<1>R<2>CO or when X is O reacting with R<1>R<2>CO and converting the product so formed to an epoxide of the formula (9) : which is reacted with 3,4-dimethoxyphenethylamine, and thereafter optionally removing the CR<1>R<2> group by hydrolysis.