3,5-Diamino-4-arylazopyrazole derivatives la,b were treated with 1,1-dicyanoprop-1-ene to yield pyrazolo [5,1-b] pyrimidines lla,b. Compound II was treated with α-substituted cinnamonitriles gave fused pyrazole derivatives IV and V. Thieno compounds Vla, b were obtained via the reaction of II with sulfur. The latter compounds were treated with benzoyl and acetyl isothiocyanates to afford the thiourea derivatives VIl and VIII, respectively. Compound VI underwent dipolar cycloaddition reaction with N-phenylmaleimide and acrylonitrile to yield the corresponding fused pyrazole derivatives IX and X, respectively. Nitration and bromination of the thieno compound VI afforded the corresponding nitro and bromo derivatives.All structures were established on the basis of elemental analyses and spectral data.