ON THE FORMATION AND REACTIVITY OF N(2),N(2')-TETRASUBSTITUTED 2,4-DIAMINO-5-(2-AMINO-4-THIAZOLYL)THIAZOLES

By the reaction of weak bases with N(2)-disubstituted 2-amino-4-thiazo liniminium chlorides 3, easily available by the reaction of thioureas 1 with alpha-chloroacetonitrile 2, N(2),N(2')-persubstituted 2,4-diami no-5-(2-amino-4-thiazolyl)thiazoles 8 are formed. These new bis-thiazo les react, as exemplified with the dimorpholino derivative 8a, with di fferent electrophilic reagent, such as phenyl isothiocyanate 9, 4-nitr o-phenyldiazonium salt 11, or 4-dialkylaminobenzaldehydes 13 at their 5H-substituted thiazole moieties to give the corresponding thioanilide s 10, azo compounds 12, and methine dyes 14, respectively. With sodium nitrite and the Vilsmeier reagent the thiazole 8a is transformed, via unstable intermediates, into the tricyclic morpholinothiazolo[4,5-c]t hiazolo[4,5-e]pyridazine 16 and dimorpholinothiazolo[4,5-b]thiazolo[4, 5-d]pyridine 19, respectively.