162374-59-6Relevant articles and documents
Antitumor benzothiazoles. Part 2. Formation of 2,2'-diaminobiphenyls from the decomposition of 2-(4-azidophenyl)benzazoles in trifluoromethanesulfonic acid
Stevens, Malcolm F. G.,Shi, Dong-Fang,Castro, Angeles
, p. 83 - 94 (2007/10/03)
Decomposition of 2-(2-azidophenyl)- and 2-(3-azidophenyl)-benzothiazoles in trifluoromethanesulfonic acid generates ?-carbocations.These reactive intermediates have been trapped by triflate anion with the nucleophile substituting para to the original azido group to yield triflate-substituted arylamines. 2-(4-Azidophenyl)-benzothiazoles and -benzoxazoles behave differently: triflate-substituted arylamines are accompanied by symmetrical or unsymmetrical benzazolyl-substituted 2,2'-diaminobiphenyls as major products.These biphenyls have been identified by their characteristic 1H and 13C NMR spectra. 2,2'-Diaminobiphenyls are formed by initial C-C coupling interactions between the ?-carbocations and undecomposed 2-(4-azidophenyl)benzazoles and not by benzidine-type rearrangements as originally proposed.Symmetrical 2,2'-diaminobiphenyls have been oxidized by (diacetoxyiodo) benzene to give novel benzazolyl-substituted benzocinnolines.
