Halogenation of N-substituted p-quinone monoimines and p-quinone monooxime esters: X. Halogenation of N-aroyl-2,5(2,3)-dialkyl-1,4-benzoquinone monoimines and their reduction products

Introduction of a strong electron-withdrawing substituent to the nitrogen atom of 2,5(2,3)-dialkyl-1,4-benzoquinone imines makes their halogenation products, the corresponding cyclohexene derivatives, very unstable and favors halogenation of methyl groups in the quinoid ring. Bromination of 4-amino-N-aroyl-2,5-dialkyl-6-bromophenols gave 2,5-dialkyl-6-benzoyloxy-3,5-dibromocyclohex-2-ene-1,4-diones.