Synthesis of Some Thiophene, Imidazole and Pyridine Derivatives Exhibiting Good Anti-Inflammatory and Analgesic Activities

A series of thiophene derivatives 1a-d & 2a-c were synthesized by condensation of 5-nitro-2-thiophene carboxaldehyde with mono and diamines respectively. Various imidazole derivatives 3a-c were obtained by condensing 4-(2- ethylamino)-1H-imidazole with 4-acetylpyridine, 2-acetylpyridine and 4-acetylbenzonitrile respectively. Pyridine derivatives 4a-e were synthesized by condensing 2-hydrazino-pyridine with various carbonyl compounds; 5a-c by condensing 2, 6-pyridine dicarbonyl dichloride with various aryl sulfonylhydrazides; 6, 7 by condensing 2, 6-dialdehyde pyridine with 2-hydrazinopyridine and anthranilonitrile respectively and compound 8 by condensing 2, 5-thiophene dialdehyde with hydrazinopyridine. All the compounds were characterized by IR, 1HNMR, Mass spectra and elemental analysis. Compounds 1a-d; 2a-c; 3a-c; 4a-e; 5a-c, 6, 7 and 8 were screened for anti-inflammatory and analgesic activities. Compounds 1b and 2c exhibited good anti-inflammatory (26.5% and 33.4% at 50mg/kg p.o. respectively) and 3a, 3c good analgesic (100% and 75% at 100 mg/kg p.o. respectively) activities. Keywords: Thiophene, imidazole, pyridine, anti-inflammatory, analgesic