Studies on dehydaro-d-erythro-and l-threo-ascorbic acid 2-arylhydrazone-3-oximes and mixed bishydrazones: conversion into substituted triazoles and pyrazolinediones

ABSTRACT

Reaction of p-nitrophenyltriazole of dehydro-D-erythro-ascorbic acid [I] with hydrazine hydrate in MeOH yielded the corresponding triazole hydrazide [II] which gave the triacetyl derivative [III]. Periodate oxidation of [II] gave the 3-formyltriazole derivative [IV] which formed a triacetyl derivative [VI]. The 3-formyl derivative [IV] was condensed with hydrazine hydrate and O-phenylenediamine to give compounds [VII] and [VIII], respectively. Treatment of [I] with ammonium hydroxide solution and MeOH gave the triazole carboxamide [IX] which produced two different acetyl derivatives [X] and [XI]. The p-nitrophenylhydrazone zone of dehydro-D-erythro-[XII] and dehydro-L- threo-ascorbic acid [XIII], reacted with phenylhydrazine to give the mixed bisarylhydrazones [XIV] and [XV], respectively, which formed the diacetyl derivatives [XVI] and [XVII]. Compound [XIV] underwent rearrangement to the corresponding pyrazole derivative [XVIII] which gave the acetyl product [XIX]. Periodate oxidation of [XVIII] gave the 3-formylpyrazole [XX] which yielded different condensation products [XXI]-[XXV]. Cupric chloride oxidation of [XV] gave the 3,6-anhydro derivative [XXVI] which characterized as its monoacetyl derivative [XXVII]