Microwave Assisted Three Component One‐pot Synthesis of Bis(aminoazolo[1,5‐ a ]pyrimidines) and Bis(aminoazino[1,2‐ a ]benzimidazoles) Bearing Thiazole Moiety

Novel bis[(thiazol‐2‐yl)acetonitrile] derivatives were prepared in good yields by the cyclocondensation of bis(bromoacetyl) derivatives with two equivalents of 2‐cyanothioacetamide in dioxane at reflux. The bis[(thiazol‐2‐yl)acetonitrile] derivatives were taken as synthetic precursors for the synthesis of novel bis(aminoazolo[1,5‐ a ]pyrimidines), bearing thiazole moiety. The target molecules were prepared by the three component one pot reaction of bis[(thiazol‐2‐yl)acetonitrile] derivatives, dimethylformamide‐dimethylacetal and several of 3‐aminopyrazoles in pyridine under microwave irradiation at 140 °C for 2 h. Using the same protocol, novel bis(aminotriazolo[1,5‐ a ]pyrimidines), bis(aminopyrimido[1,2‐ a ]benzimidazoles) and bis(aminopyrido[1,2‐ a ]benzimidazoles), incorporating thiazole moieties, were prepared by using the appropriate heterocyclic amine or 2‐(1 H ‐benzoimidazol‐2‐yl)acetonitrile instead of 3‐aminopyrazoles. The structure of the newly prepared thiazoles was confirmed via considering their elemental analyses and spectral data.