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2 Polish Journal of Chemistry

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Preparation, Separation and Identification of Some para-Substituted ONN and NNO trans-Azoxybenzenes

100%

Domański A. A. , Kyzioł J. B.

tom Vol. 75, nr 12

1839-1846

A series of para-substituted azoxybenzenes was obtained as model compounds for the investigation on the mechanism of Wallach rearrangement. Oxidation of azobenzenes with hydrogen peroxide in acetic acid solution, provided mixtures of alfa and beta isomers. Some couples of the products were separated, using chromatography and crystallization techniques, and identifiedon the basis of their carbon NMR and mass spectra. The SCSDal-gorithm can be applied to the interpretation of the I3C-NMR spectra. Recognition of the ipso andpara carbons suffice to the identification of an isomer, hence there are no strong interactions between the azoxy group and another substituent across the aromatic ring. Fragmentation of azoxybenzenes under electron impact occurs preferentially on the oxidized side of the azoxy bridge. Relative intensities of daughter ions differentiate the ONN = a. and NNO = P isomers in most cases.

Tetrakisphenol

80%

Nowakowska E. , Daszkiewicz Z. , Kyzioł J. B.

tom Vol. 72, nr 7

1191-1197

Formylation of bisphenol-A (1a), with subsequent methylation, oxidation and esterification, gave 2,2-bis-(4-methoxy-3-methoxycarbonylphenyl)-propane (11b). It was transformed into 2,2-bis-[4-methoxy-3-(2-hydroxy-2-propyl)-phenyl]-propane (12b) by the addition of methylmagnesium iodide. The carbinol was condensed with phenol in the presence of dry hydrogen chloride and the title compound was isolated as its tetramethyl ether (4b). Its structure of 2,2-bis-[4-hydroxy-3-(4-hydroxycumyl)-phenyl]-propane (4a) was confirmed by (13)C-NMR spectra. In PhOH/HCL medium tetrakisphenol (4a) decomposed and isomerized to bisphenol-A (1a).