Wyniki wyszukiwania - BazTech

1

Concomitant Rearrangement of [15N-NO@}-N-(4-Fluorophenyl)-N-methylnitramine and N-Methyl-N-phenylnitramine

Daszkiewicz Z., Kyzioł J. B.

Polish Journal of Chemistry

|

2003

|

Vol. 77 / nr 9

1217-1220

2

Structure and Rearrangement of Ring Substituted N0Methyl-N-phenylnitramines

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

Polish Journal of Chemistry

|

2002

|

Vol. 76 / nr 8

1113-1125

EN

The mechanism of the acid catalyzed nitramine rearrangement must account for the unusual sensitivity of the reaction of N-methyl-N-phenylnitramine derivatives to the ring substituents. Spectral analyses indicate the lack of interaction between the nitramino group and the second substituent through the aromatic ring. X-ray analyses confirm the spectral data: there is no conjugation between the aromatic and nitramine sextets of _-electrons. X-ray structural data also indicate that the nitramino group cannot behave as the basic centre. A reconsideration of the rearrangement rate constants of the series of ring substituted N-methyl-N-phenylnitramines lead to the conclusion that migration of the N-nitro group precedes protonation. The influence of the substituents on the reaction rates is determined by their influence on the basicity of the imino nitrogen in an intermediate. The CIDNP effect, observed in the rearrangement, results from the transformation of mobile nitrito group into the stable nitro substituent.

3

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

Domański A. A., Kyzioł J. B.

Polish Journal of Chemistry

|

2001

|

Vol. 75, nr 12

1839-1846

EN

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.

4

Dipole Moment, Molar Kerr Constant, Crystal and Molecular Structure of 3-Chloro-N-methyl-N-nitroaniline

Prezhdo V., Bykova A. S., Głowiak T., Prezhdo O. V., Daszkiewicz Z., Kyzioł J. B.

Polish Journal of Chemistry

|

2001

|

Vol. 75, nr 5

707-718

EN

Dipole moment, molar Kerr constant, crystal and molecular structure of m- ClC6H4N(CH3)NO2 (or C7H7ClN2O2) are studied. Comparison the data obtained by dipole moment and molar Kerr constant measurement, X-ray crystallographic investigation and quantum-chemical calculation show that the molecule contains a planar NNO2 nitroamino group which is twisted around the N-Cphenyl bond by ca 61.4_ from the plane of the aromatic ring. The structural data are compared with the data for p- ClC6H4N(CH3)NO2 and the influence of the substituent on the structural parameters of the molecule is established.

5

Condensation of Phenol with Methyl Pyruvate

Nowakowska E., Zaleski J., Kyzioł J. B.

Polish Journal of Chemistry

|

2001

|

Vol. 75, nr 3

419-428

EN

Methyl pyruvate reacts with phenol, in the presence of hydrogen chloride, yielding 3-(4-hydroxyphenyl)-3-methyl-2-coumaranone (1a), methyl 2,2-bis-(4-hydroxyphenyl)- propionate (2a) and methyl 2-(4-hydroxyphenyl)-2-(2-hydroxyphenyl)-propionate (3a). The structure of 1a was determined by the X-ray diffraction method and that of 2a was based on the spectral data. The latter compound was not isolated, its structure (3a) was assigned basing on the GCMS analyses and analogy with the compounds 1a and 2a. The crystal and molecular structure of racemic 3-(4-acetoxyphenyl)-3-methyl-2- coumaranone (1b) was determined at room temperature. The triclinic unit cell contains a couple of enantiomeric molecules connected by weak C-H ....O hydrogen bonds.

6

Tetrakisphenol

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

Polish Journal of Chemistry

|

1998

|

Vol. 72, nr 7

1191-1197

EN

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).