The reaction of 1-phenyl-3-alkyl-triazenes with lewis acids in benzene has been examined in order to evaluate the mechanism of the reaction of alkyl azides with electrophiles in benzene. Evolution of nitrogen gives rise to the formation of the corresponding substituted anilines by intramolecular alkylation. Alkyl benzenes are the result of an intermolecular alkylation process.
1-Phenyl-3-alkoxycarbonyl-triazenes react with aluminiumchloride in benzene by elimination of nitrogen, especially to alkylbenzenes and diphenyl; anilin is formed with practical constant yield, independently of the alkyl group. On the basis of these experimental results during the reaction of alkoxycarbonyl azides with benzene under the influence of Lewis acids triazenes are not formed as intermediates
3,3-Bis(trifluoromethyl)-2,2,2-trimethoxy-2,2-dihydro-1,4,2-oxazaphosphol-4-enes (1) on thermolysis undergo a 5→[3 + 2]cycloreversion reaction with formation of trifluoro- methyl substituted nitrile ylides (2). The latter dimerize to produce 3,6-diazaocta-2,4,6- trienes (3a, 6) which may react further to yield 6,12-dihydro-dibenzo[c,h][1,5]naph- thyridines (10), and syn/anti 4-ethylimino-1,4-dihydroisoquinolines (12/13). The naphthyridines (10) on treatment with cone. KOH are transformed into 3,3'-bis(1H-isoindoles) 11. Lithium aluminium hydride reduction of the 4-ethylimino-1,4-dihydroisoquinolines (12/13) yields 4-ethylimino-1,2,3,4-tetrahydroisoquinolines (14). A reaction mechanism for the 1,3-dipole dimerization of bis(trifluoromethyl)substituted nitrile ylides is discussed.