Oxidative demethylation of 2,3-dicyano-1,4-dimethoxynaphthalene and nitrations of some 1,4-naphthoquinones and phthalic anhydride by nitronium salts

Abstract

The nitration of 1,4-naphthoquinone derivatives and phthalic anhydride by nitronium tetrafluoroborate in tetramethylene sulphone is reported. The reaction of 2,3-dicyano-1,4-dimethoxynaphthalene with nitronium hexafluorophosphate in acetonitrile gave 2,3-dicyano-1,4-naphthoquinone and N-methylacetamide. On the basis of the above observation the mechanism of oxidative demethylation of methyl naphthyl ethers by nitronium salts is discussed.