RЕACTION OF O-ARYL(METHYL)SULFONATES OF 1,4-QUINONE MONOOXIMES WITH HYDRAZINES

Abstract

Aroylhydrazones contain the active pharmacophore group >C=N–NH–CO–. These compounds show antimicrobial, antibacterial, and even anticancer activity. In addition, aroylhydrazones are synthons in the synthesis of various heterocyclic compounds. The purpose of this work is to define the features of the reaction of aryl(benzoyl)hydrazines with O-sulfonates of 1,4-quinone monooxime and to synthesize the benzoquinone hydrazones based on them. In the result of reaction of 1,4-quinone monoxime O-sulfonates with phenylhydrazine the p-tolyl(methyl)sulfates of the corresponding aminophenols were obtained. Subsequent treatment of these sulfates with water and acidification led to sulfate destruction and formation of a mixture of the corresponding aminophenol and p-tolyl(methyl)sulfate acid. We did not obtain 1,4-benzoquinone hydrazones. Thus, in the reaction of 1,4-quinone monoxime O-sulfonates with phenylhydrazine, the first stage is the N–O bond break with reduction of quinoid ring, and this redox process is due to the high basicity of aryl hydrazines. The aroylhydrazones of 1,4-benzoquinone were obtained only in the reaction of aroylhydrazines with 1,4-quinone monoxime O-sulfonates, containing two alkyl substituents in the both orthopositions to the carbonyl group of the quinoid ring. The first step of this reaction is also the =N–O– bond breaking of the starting sulfonates and formation of corresponding quinone imines. 2,6-Disubstituted quinone monoimines have less redox potential, and aroylhydrazines are less basic than arylhydrazines, therefore, the formation of corresponding aroylhydrazones of 1,4-benzoquinone is possible. The variation of the substituent attached to the oxygen atom of the starting 1,4-quinone monooxime O-sulfonates (MeSO2 or Ts) does not affect the reaction route.