Novel reactions of N-sulfonylamines with 3-dimethylamino-2H-azirines. Competitive formation of 1,2,5-thiadiazoles, 1,2,3-oxathiazoles and acrylamidines. X-Ray molecular structure of N-(4-dimethylamino-5-methyl-2-oxo-5-phenyl-5H-1,2λ<sup>6</sup>,3-oxathiazol-2-ylidene)benzamide
作者:Ingo Tornus、Ernst Schaumann、Gunadi Adiwidjaja
DOI:10.1039/p19960001629
日期:——
Reaction of 3-dimethylamino-2,2-diphenyl-2H-azirine 3a with N-sulfonylalkylamines 2a,b provides 1,2,5-thiadiazoles 5a,b, whereas use of N-carbonylsulfonylamines 2c,e as reaction partners primarily results in 1,2,3-oxathiazoles 6a,b which isomerise to the corresponding thiadiazoles 5c,d on treatment with silica gel at room temperature. In contrast, use of 2-alkyl-3-dimethylamino-2-phenyl-2H-azir 3b,c in the reaction with the N-sulfonylamide 2c and the N-sulfonylcarbamates 2e,f leads to mixtures of thiadiazoles 5 and oxathiazoles 6 along with isomeric acrylamidines 7.