42540-72-7Relevant articles and documents
Nitrile imines and nitrile ylides: Rearrangements of benzonitrile N-methylimine and benzonitrile dimethylmethylide to azabutadienes, carbodiimides, and ketenimines. chemical activation in thermolysis of azirenes, tetrazoles, oxazolones, isoxazolones, and oxadiazolones
Begue, Didier,Dargelos, Alain,Berstermann, Hans M.,Netsch, Klaus P.,Bednarek, Pawel,Wentrup, Curt
, p. 1247 - 1253 (2014/03/21)
Flash vacuum thermolysis (FVT) of 1-methyl-5-phenyltetrazole (5b), 2-methyl-5-phenyltetrazole (1b), and 3-methyl-5-phenyl-1,3,4-oxadiazol-2(3H)-one (3b) affords the nitrile imine (2b), which rearranges in part to N-methyl-N′-phenylcarbodiimide (7b). Another part of 2b undergoes a 1,4-H shift to the diazabutadiene (13). 13 undergoes two chemically activated decompositions, to benzonitrile and CH2=NH and to styrene and N 2. FVT of 2,2-dimethyl-4-phenyl-oxazol-5(2H)-one (16) at 400 C yields 3-methyl-1-phenyl-2-azabutadiene (18) in high yield. In contrast, FVT of 3,3-dimethyl-2-phenyl-1-azirene (21) at 600 C or 4,4-dimethyl-3-phenyl- isoxazolone (20) at 600 C affords only a low yield of azabutadiene (18) due to chemically activated decomposition of 18 to styrene and acetonitrile. There are two reaction paths from azirene (21): one (path a) leading to nitrile ylide (17) and the major products styrene and acetonitrile and the other (path b) leading to the vinylnitrene (22) and ketenimine (23). The nitrile ylide PhC -=N+=C(CH3)2 (17) is implicated as the immediate precursor of azabutadiene (18). FVT of either 3-phenylisoxazol- 5(4H)one (25) or 2-phenylazirene (26) at 600 C affords N-phenylketenimine (28). The nitrile ylide PhC-=N+=CH2 (30) is postulated as a reversibly formed intermediate. N-Phenylketenimine (28) undergoes chemically activated free radical rearrangement to benzyl cyanide. The mechanistic interpretations are supported by calculations of the energies of key intermediates and transition states.
Flash-vacuum Pyrolysis of N-Vinylbenzotriazoles: Formation of N-Phenylketenimines
Maquestiau, Andre,Beugnies, Didier,Flammang, Robert,Katritzky, Alan R.,Soleiman, Mohammed,at al.
, p. 1071 - 1076 (2007/10/02)
A real time analysis of the flash-vacuum pyrolysis products of 1-vinyl-, 1-(2-methylprop-1-enyl)-, and 1-styryl-benzotriazole (3), (16), and (18) has been performed by tandem mass spectrometry.In the 500-700 deg C temperature range, these compounds lose nitrogen yielding the N-phenylketenimines (14), (17), and (19), respectively.At higher pyrolysis temperatures (3) gives indole (4) via isomerization of (14), whereas from (16) the secondary products of (17) are benzene and methacrylonitrile.In a preparative pyrolysis of (18) at 800 deg C 2- and 3-phenylindole (9) and (10) respectively, have also been detected.
