Wyniki wyszukiwania - Biblioteka Nauki

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Novel conversion of 4-aminoquinolines to new tricyclic (R,S)-3-methylazeto[3,2-c] quinolin-2(2aH)-ones and versatile one step synthesis of N-(quinolin-4-yl) carbamates from 4-aminoquinolines

100%

Kotadiya V. C. , Viradiya D. J. , Baria B. H. , Kanzariya J. S. , Kakadiya R. , Shah A.

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2014

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tom Vol. 11, iss. 3

265--276

EN

Reaction of 4-aminoquinolines with 4-nitrophenyl chloroformate have resulted in finding a novel transformation of 4-aminoquinolines to tricyclic (R,S)-3-methylazeto[3,2-c]quinolin-2(2aH)-ones. The structure of azeto-quinolinone was determined via spectroscopic and chemical methods. Various alcohols were used as nucleophiles to open the 1-azetinone ring to give the corresponding N-(quinolin-4-yl)carbamates in good yields. We also found a new and versatile one step synthesis of N-(quinolin-4-yl)carbamates by reacting 4-aminoquinolines with alkyl chloroformates in the presence of anhyd K2CO3 in acetonitrile.

2

Development and validation of an ultrasound-assisted surfactant-enhanced emulsification microextraction method for liquid chromatographic determination of carbamate residues in fruit juices

88%

Vichapong J. , Burakham R.

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tom Vol. 27, no. 1

127--145

EN

A microextraction procedure based on ultrasound-assisted surfactant-enhanced emulsification microextraction (UASEME) was optimized and validated for preconcentration of carbamate pesticides prior to fast determination using high-performance liquid chromatography (HPLC) with monolithic column. The nonionic surfactant (Tween 20) was used as an emulsifier, and chloroform was selected as an extraction solvent. The experimental parameters affecting the extraction efficiency, such as the kind, concentration, and volume of surfactant, the kind of extraction solvent and its volume, salt addition, ultrasonic extraction time, and centrifugation time, were optimized. Under the selected UASEME and HPLC conditions, separation of five carbamate pesticides (carbofuran, carbaryl, isoprocarb, methiocarb, and promecarb) was achieved within 10 min. The linearity of the method was obtained in the wide range of 2–5000 μg L -1, with correlation coefficients of 0.9931–0.9970. The limits of detection were in the range of 0.4–7.0 μg L -1. The relative standard deviations (n = 5) were less than 0.59% and 4.86% for retention time and peak area, respectively. The enrichment factors of the developed UASEME method were in the range of 33–166. The fruit juice samples (at fortified levels of 0.25, 0.50, and 1.00 mg L -1) were successfully analyzed, and the relative recoveries were obtained in the range of 81–115%.

3

Wydłużanie łańcucha wartości dodanej w przemyśle chemicznym. Cz. 3, Otrzymywanie N-podstawionych metylowych estrów karbaminowych w obecności nadkrytycznego ditlenku węgla jako katalizatora

63%

Litwinowicz M. , Kijeński J. , Kwiatkowski J. , Pasińska-Grochowy D.

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tom T. 85, nr 2

114-117

PL

Zbadano możliwość syntezy N-podstawionych metylowych estrów karbaminowych z amin i węglanu dimetylu w obecności ditlenku węgla w stanie nadkrytycznym. Przeanalizowano rolę nadkrytycznego CO2 jako katalizatora reakcji. Otrzymane produkty (N-heksylokarbaminian metylu, N-cykloheksylokarbaminian metylu, N-butylokarbaminian metylu, N-2-butylokarbaminian metylu) analizowano metodą GC-MS. Wbrew doniesieniom literaturowym, nie zaobserwowano pozytywnego wpływu nadkrytycznego ditlenku węgla na syntezę karbaminianów opisywaną metodą.

EN

Hexyl, cyclohexyl, 2-butyl or n-butyl amine was made to react with dimethyl carbonate in a 6-mL stainless steel reactor in (I) supercrit. CO2 (90), (II) N2 (90) or (III) air (1 atm) at 80°C to yield Me N-hexyl, Me N-cyclohexyl, Me N-2-butyl, or Me N-butyl carbamate in (I) poor (10.7, 2, 1.8, 15), (II) fairly high (59, 9, 3.2, 3.2, 60), and (III) high (72, 32, 7.9, 60%) yields, resp. The reported catalytic effect of supercrit. CO2 was not confirmed; CO2 had even an inhibitive effect. The carbamate yields, as also selectivities, were best at 1 atm, thus indicating a promising (phosgene-less) route to carbamates and a new way to prep. polycarbonates.

4

Badania detergentowych substancji aktywnych stosowanych w pakietach dodatków do benzyn silnikowych z wykorzystaniem analizy termicznej

63%

Krasodomski M. , Stępień Z. , Krasodomski W. , Ziemiański L. , Jęczmionek Ł.

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tom R. 70, nr 9

632--638

PL

W artykule porównano wyniki badań termograwimetrycznych dyspergująco-detergentowych substancji aktywnych typu karbaminiany, syntezowanych w INiG - PIB, z komercyjnym dodatkiem o charakterze polibutenoaminy -stosowanym w pakietach dodatków do paliw silnikowych. Przeanalizowano szczegółowo przebieg uzyskanych termogramów. Badane substancje oceniono w teście silnikowym M102. Podjęto próbę znalezienia korelacji pomiędzy wynikami testu silnikowego a oceną termograwimetryczną substancji aktywnych.

EN

Comparison of the results of thermogravimetric analysis of detergent-dispersing fuels additives, carbamates synthesized in INiG - PIB, and commercially available polybuteneamine are presented and discussed. Thermogravimetric curves were analyzed in detail. Examined substances were evaluated in engine test M102. Correlation between TGA curves, and engine tests results was proposed.