Rearrangement of dehydro-L-ascorbic acid 2-(p-chlorophenylhydrazone)‎-3-semicarbazone and thiosemicarbazone to pyrazole derivatives

الملخص EN

Boiling of dehydro-L-ascorbic acid 2-(p-chlorophenylhydrazone)-3-semicar-bazone with concentrated ammonia, afforded a pyrazole derivative, that gave tet-raacetyl- and perbenzoyl derivatives.

?eriodate oxidation and some condensation products from the pyrazole aldehyde were prepared.

The pyrazole aldehyde was reduced to the corresponding alcohol.

Similar treatment of the 3-thiosemicar-bazone with concentrated ammonia, gave the pyrazole that afforded a triacetyl derivative.