PROCESS FOR PREPARING ALKOXYALKYLIDENEHYDRAZINOPYRIDAZINE DERIVATIVES

摘要

A process for preparing a compound of the formula (4): CHEM is described wherein R3 and R4 are both hydrogen or together are =CR1R2, where R1 is hydrogen or C1-3alkyl and R2 is C1-3alkyl, carboxy or phenyl, which comprises reducing a compound of the formula (5) : CHEM 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 R1R2CO or when X is O reacting with R1R2CO and converting the product so formed to an epoxide of the formula (9) : CHEM which is reacted with 3,4-dimethoxyphenethylamine, and thereafter optionally removing the CR1R2 group by hydrolysis.