Synthesis of a new series of indolinic aminoxyls. Reaction of indoles, 2-phenylbenzothiazole, 2-phenylbenzoxazole and 2-phenyl-1,2-dihydro-4H-3,1-benzoxazin-4-one with organolithium reagents

Abstract

2-Alkyl-2-phenyl-3,3-dimethylindolines, obtained by 1,2 organolithium addition to 2-phenyl-3,3-dimethyl-3H-indole, are converted into a new series of aminoxyls by oxidation with m-chloroperoxybenzoic acid. Attempts to synthesise, in a similar way, suitable precursors such as 1,2-dihydro-2-phenyl-2-alkylbenzothiazole, 1,2-dihydro-2-phenyl-2-alkylbenzoxazole and 1,2-dihydro-2-phenyl-2-alkyl-4H-3,1-benzoxazin-4-one for other new aminoxyls failed. In fact, 2-phenylbenzothiazole, 2-phenylbenzoxazole and 2-phenyl-4H-3,1-benzoxazin-4-one react with organolithium reagents affording products deriving from ring opening. Crystal structures of 2,3-dimethyl-3-phenyl-3H-indole and bis(2-triphenylmethylaminophenyl) disulfide are also described.