Solvent-free condensation reactions to synthesize five-membered heterocyclescontaining the sulfamide fragment

P. VAZQUEZ; M.V. MIRÍFICO; M. F. ROZAS; M.V. MIRÍFICO; NELSON RODRÍGUEZ ARROYO; G. ROMANELLI

SYNTHESIS-STUTTGART

GEORG THIEME VERLAG KG

Lugar: Stuttgart; Año: 2016 vol. 2016 p. 1344 - 1352

0039-7881

We report a study of the solvent-free condensation reactionof 1,2-dicarbonyl compounds with sulfamide catalyzed by a Keggintypeacid (H3PMo12O40·nH2O, MPA) to obtain 3,4-disubstituted 1,2,5-thiadiazole 1,1-dioxide derivatives. Some reactions were also performedin solution or using nano-sized silica-supported MPA catalyst inorder to compare the results under different experimental conditions.Effects of the temperature used for the thermal pretreatment of thecatalyst, the reaction temperature, the molar ratios sulfamide/1,2-dicarbonylcompound and MPA/1,2-dicarbonyl compound, and alternativeexperimental procedures on the yield of the reaction product wereinvestigated. Under suitable experimental conditions eight compoundswere obtained in good yields. The catalyst was recycled and reused, butwith some loss of its catalytic activity. The presented synthetic methodis a simple, clean, and environmentally friendly alternative for synthesizingdifferent 1,2,5-thiadiazole 1,1-dioxide derivatives.