76670-28-5Relevant articles and documents
Formation and Thermal Reaction of O-(N-Acetylbenzimidoyl)benzamidoxime: Comparison with the Formation of 3,5-Disubstituted 1,2,4-Oxadiazoles from O-Acetylarylamidoximes and O-Aroylacetamidoximes
Ooi, Ngan Sim,Wilson, David A.
, p. 1792 - 1799 (2007/10/02)
Salts of O-(benzimidoyl)benzamidoxime have been obtained by the action of N-chloro- or N-bromo-succinimide, or the halogens, on benzamidoxime.Acetylation of the free base gave the title compound, which underwent a thermal cyclisation, with loss of acetamide, to give 3,5-diphenyl-1,2,4-oxadiazole.The mechanism of the reaction, in diphenyl ether, closely paralleled the thermal cyclisation of O-acetylarylamidoximes and O-aroylacetamidoximes, and is thought to involve a polar cyclisation step followed by rate-determining proton transfer. 13C N.m.r. spectra for 32 oxime, amidoxime, O-acetylamidoxime, 5-methyl-1,2,4-oxadiazol-3-yl, and 3-methyl-1,2,4-oxadiazol-5-yl groups on the phenyl ring are calculated.