Facile synthesis of new oxothiazolo[3,2-c] pyrimidine carbonitriles via mannich cyclisations

Thiazolopyrimidine scaffolds are known in the recent literature for their synthetic examples and their many important biological activities. But, one of the thiazolopyrimidine cores, thiazolo[3,2-c]pyrimidines, has very rare examples in the terms of synthesis and biological activity studies. In previous years, some syntheses with azole approach and cytotoxic activity studies on thiazolo[3,2-c]pyrimidines have been reported for the first time with the efforts of our research group. In order to extend the scope of thiazolo[3,2-c]pyrimidine chemistry and increase the number of structural examples, a facile and efficient synthesis of novel 3-oxothiazolo[3,2-c]pyridimine carbonitriles (102) were planned in the present dissertation study. In this regard, firstly, a new heterocyclic enamine precursor (64b) was prepared and characterized by IR and NMR analyses. In the rest of the study, after performing some optimizations on a model reaction, novel examples of 3-oxothiazolo[3,2-c]pyrimidine carbonitriles (102a-v) were prepared in excellent yields via Mannich cyclizations of the heterocyclic enamine, 2-(4-oxothiazolidin-2-ylidene)-8-carbonitrile (64b) with formaldehyde 9 and primary amines (8) in minute reaction times under MW conditions. Then, the structures of target compounds (102a-v) were elucidated by fully characterizing by IR, NMR and HRMS data in the last part of the study.