Studies on quinones

Abstract

The reaction of 1,2-diaminoanthraquinones with thionyl chloride has given anthra[1, 2-c]-1, 2, 5-thiadiazole-6, 11-diones a new group of heterocyclic anthraquinone derivatives. In the reaction of anthra [1,2-c]-1,2,5-thiadiazole-6,11-dione(I) with primary and secondary amines, the amine residue enters position 4 and forms the corresponding 4-amino derivatives VI with a yield of up to 85%. The same compounds are obtained by the reaction of 4-haloanthra[1,2-c]-1,2,5-thiadiazole-6,11-diones (IIa, b). In 5-chloroanthra[1,2-c]-1,2,5-thiadiazole-6,11-dione (IIc), where it would appear, the halogen should be particularly mobile, the chlorine atom does not undergo exchange and, as in I, the replacement of the hydrogen in position 4 takes place. Some aspects of the influence of the thiadiazole ring on the anthraquinone nucleus are discussed.