The synthesis and characterization of some ortho-substituted phenoxyalkanoic acids and their derivatives

The synthesis of 2-phenoxyalkanoic acids (ethanoic, propanoic, butanoic) was realized by the reaction of ortho-hydroxybenzamide respectively N-phenyl-o-hydroxybenzamide with ?-halogenated acids in aqueous sodium hydroxide solution. 2-[o-(carbamoyl)phenoxy]-2-methyl- and 2-[o-(phenylcarbamoyl)phenoxy]-2-methyl- propanoic acids were obtained by reaction of the appropriate amide with acetone, chloroform and sodium hydroxide. Ethyl esters of 2-phenoxyalkanoic acids were obtained by the reaction of the amide with ethyl esters of ?-halogenated acids in different reaction media. Starting from the ethyl esters of 2-[2-(N-phenylcarbamoyl) phenoxy]alkanoic acids with hydrazine 2-[2-(N-phenylcarbamoyl)phenoxy]alkanoic acids hydrazides were obtained, which are considered key intermediates for the synthesis of several series of new compounds. Schiff bases and N-imido-derivatives were obtained by condensation of hydrazide with substituted aromatic aldehydes respectively maleic anhydride. The synthesized compounds were characterized by physico-chemical methods (FTIR, NMR and mass spectrometry). .

Infrared Spectra-Structure Correlations for Monohalogenated Monocarboxylic Acids

The ir spectra of 16 monohalogenated monocarboxylic acids have been recorded over the range 4000–200 cm−1. Attempts have been made to find useful spectra structure correlations which would serve to distinguish these acids from their unsubstituted analogs. It is concluded that differentiation of halogenated acids, either from unsubstituted acids or from each other, is not possible on the basis of consistent group frequencies, which forces one to resort to reference spectra for identification of these compounds. The one exception is provided by the alpha chloro-substituted compounds, which can, tentatively, be differentiated from both unsubstituted acids and other halogen-substituted acids. In contrast to previous reports, alpha halogen-substituted acids cannot be differentiated from the others unless the halogen is chlorine.