Abstract: A series of isolated/fused of pyrazole, isoxazolo, pyrimidine, pyrimidine thione, spiro thiazolodine and spiro β-lactam derivatives incorporating to 4-acetyl-5-amino-3-methyl-1-phenyl-2-pyrazoline have been synthesized by different methods of chemical reactions. The structure assignments of these compounds, based on chemical and spectroscopic evidence were deduced from their IR, 1H NMR, elemental analysis and mass spectrometry.