2,3-Dihydro-1,4-benzoxazine-6,7-quinones and related compounds

Abstract

Treatment of suitably diaminated 1,4-benzoquinones (I) or monoaminated 2-hydroxy-1,4-benzoquinones (II) with sulphuric acid gives the title compounds. These exist predominantly in the o-hydroxy-p-quinone imine form rather than the p-amino-o-quinone form in chloroform solution, whereas in ethanol the tautomers are present in approximately equal amounts.