SYNTHESIS OF 2-ARYL-3-METHYLBENZO[g]INDOLES FROM 2-(ARYLETHYNYL)-1,8-BIS(DIMETHYLAMINO)NAPHTHALENES: NEW EXAMPLES OF [1,3]-MIGRATION INVOLVING N-METHYL GROUP

Abstract

The Sonogashira coupling of 1,8-bis(dimethylamino)-2-iodonaphthalene with 2-nitro-, 4-nitro-, 4-(trifluoromethyl)-, and 4-methoxyphenylacetylenes was used to obtain new 2-(arylethynyl)-1,8-bis(dimethylamino)naphthalenes. Three of the four alkynes, except for the o-nitrophenyl derivative, were isomerized in the presence of palladium and porcelain catalysis to the corresponding 2-aryl-9-(dimethylamino)-1,3-dimethyl-1H-benzo[g]indoles.