Facile Route to Novel Pyrazolo[3,4-d]pyrimidine, Imidazo[1,2-b] pyrazole, Pyrazolo[3,4-d][1,2,3]triazine, Pyrazolo[1,5-c][1,3,5]triazine and Pyrazolo[1,5-c][1,3,5]thiadiazine Derivatives

A regioselective synthesis of novel pyrazolo[3,4-d]pyrimidines, imidazo[1,2-b]pyrazoles, pyrazolo[3,4-d][1,2,3]triazine, pyrazolo[1,5-c][1,3,5]triazine and pyrazolo[1,5-c][1,3,5]thiadiazine incorporating a thiazole moiety was described via the reactions of the versatile, readily accessible 5-amino-3-(phenylamino)-N-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxamide (1) with each of DMF-DMA, phenylisothiocyanate, chloroacetyl chloride, phenacyl bromide, benzoylisothiocyanate and formalin, respectively. All structures of the newly synthesized compounds were elucidated by elemental analysis and spectral data.