SYNTHESIS OF 5-ALKOXY-4-ALKYLAMINO-1,2-BENZOQUINONES

A simple and efficient method is described for a general synthesis of 4-dialkylamino-5-methoxy-1,2-benzoquinones 3 which involves, in polar solvents, a regioselective (> 95 %) nucleophilic monosubstitution by a wide range of secondary aliphatic amines on an easily prepared 1,2-qu inone 1. Regioselectivity is not observed in the reaction of primary a mines with 1, but a further reaction with an alcohol in basic medium a llows valorization of the undesirable product.