Preparation of a 4-methoxyphenylhydrazine and some other arylhydrazines

Abstract

4-Methoxyphenylhydrazine was prepared in 70% yield from 4-anisidine by converting it into the diazonium salt and reducing the latter with stannous chloride at -25º. When the reaction was conducted at 0º the parent amine, 4 anisidine, was regenerated by reductive cleavage of the N-N bond of the hydrazine as it formed from the diazonium salt in the presence of excess stannous chloride.The required 4-methoxyphenylhydrazine was then recovered only in impure form in poor yield. The reactivities of a selection of substituted phenylhydrazines with stannous chloride were compared and the 4-methoxy derivative found to be by far the most reactive. The differences in reactivity were reflected in the different reaction conditions under which the arylhydrazines could be formed in good yield by reduction of the corresponding diazonium salts.