Reactions of 1,2-Dihydro-2-methyl-2-phenyl-3H-indole-3-one with Various Halogenating Reagents.
摘要:
1,2-Dihydro-2-methyl-2-phenyl-3H-indole-(indoxyl) undergoes halogenation with N-chloro- and N-bromosuccinimide and N-chlorobenzotriazole forming 5- and/or 7-halogenated indoxyls. Initial one-electron transfer could be ruled out, and the reaction seems to occur either by an electrophilic aromatic substitution process or by the intermediate formation of N-haloindoxyl, which rearranges via a nitrenium ion to the reaction products. Tn experiments with I-2/AgClO4, FeCl3, Ar3NSbCl6/Bu4NCl, where the radical cation is really formed, 5,5'-dimers and halogenated dimers were always obtained together with halogenated monomers. In the reaction with CuCl2 only the 5-substituted monomer was obtained.