Synthesis of Substituted Dithiazolo[4,5-b:5′,4′-e] Pyridine-2,6-Diamines Based on the Interaction of 2,4-Diaminothiazole With Aldehydes

The reaction of generated in situ 2,4-diaminothiazole with various aldehydes was investigated. For the first time, it was shown that the considered process leads to the formation of dithiazolo[4,5-b:5′,4′-e]pyridine system. Relied on the performed research, the general method for the preparation of substituted dithiazolo[4,5-b:5′,4′-e]pyridine-2,6-diamines was developed. The advantages of the elaborated synthetic procedure are easily available starting compounds, atom economy, and simple isolation of target products without chromatographic purification. The application of the presented approach to related 2,4-diaminoselenazole allowed us to design a previously unknown bis([1,3]selenazolo)[4,5-b:5′,4′-e]pyridine system. The structures of the two obtained dithiazolo[4,5-b:5′,4′-e]pyridine-2,6-diamines were confirmed by X-ray analysis.