An original one-pot synthesis of dialkyl-substituted anthraquinones

2,3-Bis(chloromethyl)-1,4-naphthoquinone reacts with primary nitroalkanes in a one-pot synthesis to give a series of anthraquinones bearing two n-alkyl substituents at C-2 and C-3 in good yields. The reaction is shown to proceed by two consecutive S(RN)1 processes followed by base-promoted nitrous acid elimination, electrocyclic ring-closure and dehydrogenation. In comparison with the classical Diels-Alder reaction, the advantage of this route is the simplicity of starting-material preparation.