This study is concerned with the synthesis of new 1,2,4-triazoles, 1,3,4-thiadiazoles, and 1,3,4-thiadiazines derivatives. Derivatives 3a-i were obtained by condensation of 4-amino-3-(4-pyridine)-5-mercapto-1,2,4-triazole 1 with the appropriate aldehyde. Compounds 4a-i were synthesized in a one pot reaction involving compounds 3a-i, formaldehyde, and morpholine. Condensation of compound 1 with the appropriate acids or 4-substituted phenacyl bromide gave compounds 6a-d and 8a-f respectively. The chemical structures of the newly synthesized derivatives were elucidated using different spectral and elemental methods of analysis. All compounds were evaluated for their anti-inflammatory activity and the most potent derivatives were tested for their analgesic activity using indomethacin as a reference drug. In addition, ulcerogenicity and $LD_{50}$ for the most active compounds were evaluated. Moreover, the antibacterial activities of the newly synthesized derivatives were investigated.