90000-41-2Relevant articles and documents
Reactions of Oximes with Thianthrene Cation Radical in Nitrile Solvents. Cycloaddition To Form Oxadiazoles and Deoxygenation To Form Nitriles
Chiou, Shishue,Hoque, A. K. M. M.,Shine, Henry J.
, p. 3227 - 3232 (1990)
Reactions of eight oximes, RCH=NOH (1a, R= C6H5; 1b, R= 4-CH3C6H4; 1c, R= 4-NO2C6H4; 1d, R= 4-CH3OC6H4; 1e, R= 2-CH3OC6H4; 1f, R= 1-naphthyl; 1g, R= C5H11; 1h, R= C4H9), with thianthrene cation radical perchlorate (Th.+ClO4-) in acetonitrile under argon were studied.The major product from the oxime in all cases, but of 1d, was the nitrile, RCN.The anticipated product of oxidative cycloaddition, namely, a 3-R-5-methyl-1,2,4-oxadiazole (2), was obtained in substantial yield (2d, 66percent) only in the case of 1d.An isomeric 5-R-3-methyl-1,2,4-oxadiazole (3) was obtained from some reactions, that is, 3c alone from 1c, and a mixture of 2a and 3a from 1a.Neither 2 nor 3 was obtained in measurable amounts from reactions of 1g and 1h.The aldehyde (RCHO) was obtained in small yields from each reaction.Thianthrene (Th) and thianthrene 5-oxide (ThO) were also major products.Studies with -1b and -1d showed that the oxgen atom in 2 came entirely and in ThO primarily from the oxime.Studies of workup with H218O showed that the workup water was the source of the oxgen atom in RCHO and to a small extent in ThO.Explanations are given for the formation of 2 by a stepwise addition of RCH=NOH.+ (1.+) to solvent nitrile and of 3 by the reaction of solvent nitrile with an oxaziridine cation radical (7, obtained from 1.+).
