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

Abstract

AbstractNovel 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‐(1H‐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.