1,4-Naphthoquinone derivatives having a nitro group in the quinoid part of the molecule are poorly understood. The nitration of 1,4-naphthoquinone [1] and 2,3-dichloro- 1,4-naphthoquinone [2] in fairly stringent conditions afforded the corresponding 5-nitro-1,4-naphthoquinones. The nitration of 2-hydroxy-1,4-naphthoquinone and its derivatives with conc. nitric acid or with nitrating mixture results in the corresponding 2-hydroxy-3-nitro- 1,4-naphthoquinones [3]. When ...
