Activated sterically strained C=N bond in N-substituted p-quinone mono- and diimines: XV. Synthesis, structure, and reactions with alcohols of N-carbamoyl-1,4-benzoquinone imines

The reaction of 4-aminophenols with N -nitrourea or with sodium cyanate in acetic acid gave the corresponding 4-ureidophenols which were oxidized to N -carbamoyl-1,4-benzoquinone imines, substituted N -(4-oxocyclohexa-2,5-dien-1-ylidene)ureas. N -(2,6-Dimethyl-4-oxocyclohexa-2,5-dien-1-ylidene)urea possessing activated sterically strained C=N bond reacted with alcohols to afford N -(1-alkoxy-2,6-dimethyl-4-oxocyclohexa-2,5-dienyl)ureas.