Triazines and related products. Part VI. Synthesis and properties of 4-amino-2(2H)-imino-s-triazino[1,2-c][1,2,3]-benzotriazines

Abstract

2,4-Diamino-6-aryl-s-triazines (III) have been prepared for examination as potential tumour-inhibitory agents. 2,4-Diamino-6-(2-aminophenyl)-s-triazines (IV) react with formic acid and triethyl orthoformate to form the formylaminophenyl- and ethoxymethyleneaminophenyl-s-triazines respectively, but in formamide 4-aminoquinazolines are produced. Diazotisation of the amines (IV) afforded in certain instances stable diazonium salts (X) which cyclised in base to derivatives of s-triazino[1,2-c][1,2,3]benzotriazine (XI). Replacement of the diazogroup in the s-triazinobenzotriazines (XI) by hydrogen, and by amino-, chloro-, hydroxy- and azonaphthol substituents demonstrates the similarity between the chemical properties of 1,2,3-benzotriazines and diazonium compounds. Reduction of the s-triazinobenzotriazines with stannous chloride in ethanol yielded s-triazino-[1,2-b]indazoles (XIV), which were also formed by cyclo-deamination of the hydrazines (XV) and by thermolysis of the azides (XVII). The s-triazinobenzotriazenes decompose homolytically in boiling nitrobenzene to afford a mixture of isomeric nitrobiphenyls: the mass spectra of the isomers are discussed.