Synthesis, characterization, antioxidant and quantum chemical calculations of some new thiophene, diazepine and pyrimidine derivatives containing sulfamoyl moiety

Abstract

Novel ketene N, S-acetal 4 was readily prepared by the reaction of 3-oxo-butanamide 1with isothiocyanate sulfonamide 2 in the presence of potassium hydroxide, followed by alkylation of the non-isolated salt with methyl iodide. Also, Treatment of non- isolated 3 with dilute HCl afforded the corresponding thiocarbamoyl derivative 5. The reaction of compound 4 with various bifunctional nucleophilic reagent such as thiourea, hydrazine, ethylenediamine and o-phenylenediamine to produce pyrimidine, pyrazole, diazepine and benzodiazepine derivatives 6, 7, 8 and 9, respectively. The non-isolated intermediate 3 was reacted with -halo carbonyl, such as ethyl chloroacetate, p-methoxy-phencyl bromide, chloroacetonitrile and chloro arylacetamide afforded the corresponding thiophene derivatives 10, 12, 14 and 17a,b. Finally, compound 3 reacted with chloroacetyl chloride to give thiozolidinone derivative 19. These compounds have been characterized using IR, 1H NMR and mass spectra. Some of the new synthesized compounds were evaluated as antioxidant agents by phosphomolybdenum method. The results indicated that the derivative 4 exhibited more potency than standard ascorbic acid. Quantum chemical calculations used for predict the stability and reactivity of some new synthesized compounds through energy gap between EHOMO and ELUMO. The quantum chemical calculation gives good approval according to experimental characterization of some new compounds as IR, 1H NMR and mass spectra.