Ortho-Disubstituted F-Benzenes. III. Preparation of (F-Benzo)heterocyclic Compounds from F-Benzoic Acid and F-Phenol, and the Reactions of Some Intermediary F-Benzoyl- and F-Phenoxy Compounds

Abstract

Abstract With the intention of achieving the selective ortho-substitution of F-benzoic acid and F-phenol via intramolecular nucleophilic cyclization, preparation of some requisite precursory F-benzoyl- and F-phenoxy compounds and their nucleophilic cyclization reactions were examined. 1,2-(F-Benz)isoxazol-3(2H)-one, 2-(p-tolyl)-1,2-(F-benz)isoxazol-3(2H)-one, 1,3-dimethyl(F-benzo)pyrimidine-2,4(1H,3H)-dione, and 1,4-(F-Benz)oxazin-3(2H)-one were obtained from the respective precursory F-benzohydroxamic acid, N-(p-tolyl)-N-hydroxy-F-benzamide, N,N′-dimethyl-N-(F-benzoyl)urea, and 2-(F-phenoxy)acetohydrazide. Attempted cyclizations of 2-(F-phenoxy)acetohydroxamic acid and (F-phenoxy) acetic acid were accompanied by simultaneous ring-opening and resulted in the formation of the identical product: (2-hydroxy-F-phenoxy)acetic acid. Transamidation of ethyl F-benzoate with hydroxylamine failed to give F-benzohydroxamic acid, which was then obtained by the catalytic debenzylation of N-benzyloxy-F-benzamide.