3,3 '-(Arylmethylene)bis(2-hydroxynaphthalene-1,4-dione) as the main product of the Mannich reaction of 2-hydroxy-1,4-naphthoquinone with 4H-1,2,4-triazol-4-amine and various aldehydes

摘要

The Mannich reaction of lawsone with various aldehydes and 4H-1,2,4-triazol-4-amine gave unexpected 3,3'-(arylmethylene) bis(2-hydroxynaphthalene- 1,4-dione) derivatives. With 2,4-dihydroxybenzaldehyde under the same conditions, it led to the formation of 3-hydroxy-12(3-hydroxy-1,4-dioxo-1,4-dihydronaphthalen-2-yl)-6H-benzo[b] xanthene-6,11(12H)-dione instead of various triazolylaminonaphthoquinones.