Photochemical nucleophilic substitution of methoxy-benzoquinones and -naphthoquinones with methylamine. Examples of substitution reactions following different thermal and photochemical pathways with high regiospecificity

Abstract

Thermally and photochemically induced substitution reactions between 2-methoxy-1,4-naphthoquinone and methylamine follow different pathways with high regiospecificity: thermal reaction results in replacement of the 2-methoxy group by the amine, whereas photosubstitution involves replacement of hydrogen at the 3-position; 2,6-dimethoxy-1,4-benzoquinone shows a similar behaviour.