[Reactions of isopropyl-alkylamine with 2,3-dichloro-1,4-naphthoquinone and 2,3-dichloro-1,4-naphthoquinone/acetaldehyde].

Isopropyl-alkylamines 2 react with 2,3-dichloro-1,4-naphthoquinone (1) to give red 2-chloro-3-isopropyl-alkylamino-1,4-naphthoquinones 3 and with 2,3-dichloro-1,4-naphthoquinone/acetaldehyde to give blue 2-chloro-3-isopropylalkylamino-vinyl-1,4-naphthoquinones 7. It is evident that the formation of 7 is preferred sterically to the formation of 3. The reaction between 2, 1 and acetaldehyde give also red aminoquinones 3 and blue green 2-chloro-3-(4-isopropylalkylamino-buta-1,3-dienyl)-1,4-naphthoquinone like 11.