An Efficient Synthesis of (5-(3-Hydroxyquinoxalin-2-Yl)-1, 3, 4-Thiadiazol-2-Yl) Benzamides and (3-(3-Hydroxyquinoxalin-2-Yl)-5-Mercapto-4h-1, 2, 4-Triazol-4-Yl) (Aryl) Methanones

Ethyl-3-hydroxyquinoxaline-2-carboxylate is reacted with hydrazine hydrate to offered 3- hydroxyquinoxaline-2-carbohydrazide (1), which on condensation with different isothiocyanates gave (2- (3-hydroxyquinoxaline-2-carbonyl) hydrazine-1-carbonothioyl)benzamides (2). Compound 2 is treated with conc. H2SO4 and NaOH to offered (5-(3-hydroxyquinoxalin-2-yl)-1,3,4-thiadiazol-2-yl)benzamides (3) and (3-(3-hydroxyquinoxalin-2-yl)-5-mercapto-4H-1,2,4-triazol-4-yl)(aryl)methanones (4), respectively. The structures of all synthesized compounds were confirmed by spectral analyses.