Fluorinated heterocyclic compounds. A photochemical synthesis of 3-amino-5-perfluoroaryl-1,2,4-oxadiazoles
作者:Silvestre Buscemi、Andrea Pace、Rosa Calabrese、Nicolò Vivona、Pierangelo Metrangolo
DOI:10.1016/s0040-4020(01)00524-5
日期:2001.7
methodology for the synthesis of 3-amino- (or 3-N-substituted amino) 5-pentafluorophenyl-1,2,4-oxadiazoles is reported. Irradiation of 3-pentafluorobenzoylamino-4-methyl-1,2,5-oxadiazole (Furazan) at 254 nm in methanol and in the presence of ammonia, primary or secondary aliphatic amines produces 3-amino-, 3-(N-alkylamino)-, 3-(N,N-dialkylamino)-5-pentafluorophenyl-1,2,4-oxadiazoles. The photoreaction
报道了合成3-氨基-(或3- N-取代的氨基)5-五氟苯基-1,2,4-恶二唑的光化学方法。在甲醇中于254 nm辐射3-五氟苯甲酰基氨基-4-甲基-1,2,5-恶二唑(呋喃山),在氨的存在下,伯或仲脂族胺生成3-氨基-,3-(N-烷基氨基) -,3-(N,N-二烷基氨基)-5-五氟苯基-1,2,4-恶二唑。光反应遵循呋喃山环的断裂模式,其中乙腈被挤出,并形成氮亲核试剂将捕获的对应片段。取决于试剂的性质,还通过氮亲核试剂和/或溶剂置换了在第一形成的恶二唑的C(5)-五氟苯基部分上的氟阴离子。通过相同的光化学方法,还描述了3-甲氧基-5-五氟苯基-1,2,4-恶二唑的合成。