78365-69-2Relevant academic research and scientific papers
New Unusually Photochemical Reactions of 3-Aminosydnones
Gotthardt, Hans,Reiter, Friedemann
, p. 1737 - 1745 (2007/10/02)
The light-induced reactions of the 3-amino-4-(phenylthio)sydnones 1a - d surprisingly produce beside diphenyl disulfide the sydnone isomers 11a - d with 2-aza-1,3-diazoniacyclopentadiene-1,4-diolate structure in 2,3 - 27percent yields.The photoreactions of the sydnones 1a, c in the presence of dimethyl acetylenedicarboxylate proceed with formation of the photoisomers 11a or 11c (17percent), the benzothiophene derivative 14 (9 - 7percent), the (phenylthio)fumaric ester 15 (5percent) as well as the pyrazole derivatives 13a (18percent) or 13c (8percent), respectively.The latter are results of a thermal cycloaddition reaction of the photochemically generated nitrile imine intermediate of type 9 to dimethyl acetylenedicarboxylate.Beside 14 (30 - 43percent), the same pyrazole derivatives 13a, c are obtained on irradiation of the sydnone isomers 11a or 11c in the presence of dimethyl acetylenedicarboxylate, respectively.The analogous photoreaction of the system 1d/dimethyl acetylenedicarboxylate produces 11d (0.6percent) and 13d (1.8percent) in low yields.
