1,3-Cycloaddition of Benzonitrile Oxides to Diazepines. I. 1-Ethoxycarbonyl-5-methyl-1,2-diazepine
作者:Paolo Beltrame、Enzo Cadoni、Maria M. Carnasciali、Gioanna Gelli、Adolfo Lai、Angelo Mugnoli、Marcella Pani
DOI:10.3987/com-92-6073
日期:——
Stable aryl nitrile oxides (1a-e) and 1-ethoxycarbonyl-5-methyl-1,2-diazepine (2) undergo 1,3-cycloaddition reactions to give isomeric 1,2,4-oxadiazole (3), 4,5-dihydroisoxazole (4) and isoxazole (5) derivatives, the first one being in any case the most abundant product. Overall kinetics were measured at temperatures in the range 50-90-degrees-C, in 1,1,2,2-tetrachloroethane and mixtures of the latter with DMF; rate coefficients for the parallel reactions were, thus, obtained. Substituent and solvent effects are discussed.