Formation of 4-hydroxy-3-(α-hydroxybenzyl)-4-phenyl-2-pyrazolin-5-one from the interaction of 3,6-bis-(α-hydroxybenzyl)-s-tetrazine with potassium hydroxide in methanol

Abstract

4-Hydroxy-3-(α-hydroxybenzyl)-4-phenyl-2-pyrazolin-5-one has been obtained from the reaction of methanolic potassium hydroxide with 3,6-bis-(α-hydroxybenzyl)-s-tetrazine and its structure proved by an alternative synthetic route. The mechanism of the rearrangement has been shown to involve a hydride transfer to a further tetrazine molecule which undergoes reduction to the dihydro-derivative.