A new series of of novel pyrazole derivatives i.e, 2-arylsulfanyl-1-(5-phenyl-3-thiazol-2-yl-4,5-dihydro-pyrazol-1-yl)-ethanone have been synthesized in good to excellent yields by employing 2-acetylthiazole and 3-phenyl-1-thiazol-2-yl-propenone, 2-(5-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-thiazole and 2-chloro-1-(5-phenyl-3-thiazol-2-yl-4,5-dihydro-pyrazol-1-yl)-ethanone as reactive intermediates.