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1

Synthesis of (R) and (S)-2-[4-(4'-difluoromethylsulfonyl-2'-nitrophenylamino)phenoxy]propionic acid derivatives as new pesticides

Ochal Z., Gałązka J.

Polish Journal of Applied Chemistry

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2006

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Vol. 50, nr 1-2

13-27

EN

The synthesis of (R) and (S)-2-phenoxypropionie acid derivatives bearing difluoromethylsulfonyl-nitrophenyl group, such as: phcnoxypropionamides, phenoxypropionhydrazides, phenoxypro-pionhydrazones and phcnoxypropionsemicarbazides as a new compounds with potential pesticidal activity is reported. The title compounds were obtained starting from the proper phenol synthesized from difluoroniethyl-3-nitro-4-chlorophenyl sulfone and 4-aminophenole. Obtained phenol was transformed into optically active phenoxypropionic acid ethyl esters in reaction with (S)-(-)-tosy!oxy ethyl lactate and (R)-(+)-2-chloropropionic acid ethyl ester. They were hydrolyzed, and then obtained acids were converted into chlorides. Phenoxy acid chlorides were subjected to the reaction with amines. Phenoxypropionic acid ethyl esters are transformed in reaction with hydrazine hydrate into hydrazides, which were used to the reaction with aldehydes and isocyanates. Optical purity of the synthesized compounds were determined using HPLC equipped with chiral columns. Characteristic IR spectroscopic data and microelernentary analyses of the new products are reported.

2

Synthesis of (R) and (S) 2-phenoxypropionamide derivatives as new compounds with promising pesticidal activity

Ochal Z., Gajadhur A.

Polish Journal of Applied Chemistry

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2004

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Vol. 48, nr 1-2

33-44

EN

The synthesis of (R) and (S) 2-phenoxypropionamide derivatives as new compounds with potential pesticidal activity is reported. The title compounds were obtained by the three - step synthesis starting from (R) and (S) 2-phenoxypropionic acid ethyl esters. Esters were hydrolyzed, and obtained acids were converted into chlorides applying the thionyl chloride. Phenoxy acid chlorides were subjected to the reaction with amines, to give the title compounds. Optical purity of the synthesized compounds were determined using HPLC equipped with chiral columns. Characteristic IR spectroscopic data and the results ofmicroelemental analyses of the new products are given.

PL

Przedstawiono syntezę nowych pochodnych (R) i (S) 2-fenoksypropionamidu jako związków o spodziewanej aktywności pestycydowej. Związki te otrzymywano w trójetapowej syntezie, wychodząc z estrów etylowych kwasu (R) i (S) 2-fenoksypropionowego. Estry te hydrolizowano, a otrzymane kwasy przekształcano w chlorki kwasowe stosując chlorek tionylu. Chlorki fenoksykwasów poddano reakcji z aminami uzyskując tytułowe pochodne. Czystość optyczną syntezowanych związków określano metodą HPLC stosując chiralne kolumny. Podano charakterystyczne pasma IR oraz wartości analizy elementarnej otrzymanych nowych pochodnych.

3

Badania układów racemat/enancjomer oraz określanie nadmiaru enancjomerycznego za pomocą wysokorozdzielczej spektroskopii NMR w cieczy i w ciele stałym

Tadeusiak E. J.

Wiadomości Chemiczne

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2003

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[Z] 57, 5-6

367--389

EN

Over the past decade there has been a surge of interest in enantioselective synthesis which has led to find convenient metods of measuring enantiomeric purity or enantiomeric excess of many compounds. The enantiomeric excess can be determined by the following principal methods: (a) chiroptical, (b) chromatography (GS, HPLC, TLC ), (c) isotopic dilution, (d) kinetics, (e) electrophoresis, (f) calorimetry, (g) nuclear magnetic resonance. In this paper there are presented studies, which were performed in aim to determine of ee by NMR in liquid and solid state. Determination of enantiomeric purity using NMR in liquid requires the intervention of a chiral auxiliary to convert an enantiomeric mixture into a mixture of diastereomers. Three types of chiral auxiliary are widely used. Chiral derivatising agents (CDAs) form diastereomers while chiral solvating agents (CSAs) and chiral lanthanide shift reagents (CLSRs) form diastereomeric complexes in situ with the substrate enantiomers. In recent years Solid–State NMR (SS NMR) has emerged as a powerful tool for the analysis of solids. In particular the ODESSA (One Dimensional Exchange Spectroscopy by Sideband Alternation) technique permit to recognize differences between enantiomers and racemates as well to assess the enantiomeric excess.