2-Substituted and 2,6-disubstituted 1,4-benzoquinone 4-oxime methyl ethers

Abstract

The preparation and physical properties of seven compounds in the title series are described. The formation of glyoxal bis(aryl)nitrone derivatives as by-products of methylation of some 1,4-benzoquinone 4-oximes is rationalized. The syn and anti isomers of the title compounds can be equilibrated either thermally or under conditions of acid catalysis. The effects of substituents at C2 on the position of the syn-anti equilibrium are very similar to their effect in other derivatives of the corresponding 1,4-benzoquinone 4-oximes. N.m.r, parameters and other spectroscopic data are listed and discussed.