1-(2-(4,5-Dihydro-3-(4-methyl-2-phenylthiazol-5-yl)-5-phenylpyrazol-1-yl)-4-substituted thiazol-5-yl)-2-phenyldiazene were synthesized from hydrazonoyl halides and 3-(4-methyl-2-phenyl-1,3-thiazol-5-yl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbothioamide in ethanolic triethylamine. Also, pyrazolo[5,1-a]pyrimidines, 2,3,6-trisubstituted pyridines, and pyrazolo[3,4-d]pyridazines were obtained from sodium salt of 3-hydroxy-1-(4-methyl-2-phenylthiazol-5-yl)prop-2-en-1-one and different heterocyclic amines. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. The newly synthesized compounds were tested towards different microorganisms. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.