<i>ortho</i>-Disubstituted <i>F</i>-Benzenes. I. Preparation of (<i>F</i>-Benzo)heterocyclic Compounds from <i>F</i>-Aniline and the Reactions of Some Intermediate (<i>F</i>-Phenyl)amino Compoundst

Abstract

Abstract With the intention of achieving the selective ortho-disubstitution of F-aniline via intramolecular nucleophilic cyclization, syntheses of some requisite intermediate (F-phenyl)amino compounds and (F-benzo)heterocyclic compounds were investigated. 2-Phenyl-F-benzoxazole, 2-phenyl-F-benzimidazole, and 2,3-dihydro-1,4-(F-denz)oxazin-3-one were obtained from the respective precursors: benz-F-anilide, N-(F-phenyl)benzamidine, and hydroxyacet-F-anilide. 2-Phenyl-F-benzothiazole was obtained by treating benz-F-anilide with phosphorus pentasulfide. Hydrolytic dehalogenation of haloacet-F-anilide failed to give hydroxyacet-F-anilide, but it was obtained successfully by catalytic debenzylation of benzyloxyacet-F-anilide. The reactions of iodoacet-F-anilide with silver nitrate and acetate yielded 2-nitrate and 2-acetate, respectively. The reaction with diamminesilver(I) nitrate resulted in a reductive deiodination which gave acet-F-anilide. This exceptional reactivity was ascribed to the strong electron-withdrawing effect of the F-phenyl group.