Isobutyl Chloroformate

2021 ◽  
Keyword(s):  
Isobutyl Chloroformate

scholarly journals Identification and Determination of 1,3-Thiazinane-4-carboxylic Acid in Human Urine—Chromatographic Studies

2022 ◽  
Vol 23 (2) ◽  
pp. 598
Author(s):  
Justyna Piechocka ◽  
Natalia Litwicka ◽  
Rafał Głowacki
Keyword(s):  
Carboxylic Acid ◽  
Human Urine ◽  
Clinical Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Aqueous Environment ◽  
Limit Of Quantification ◽  
Isobutyl Chloroformate ◽  
United States Food ◽  
States Food

It is well established that homocysteine (Hcy) and its thiolactone (HTL) are reactive towards aldehydes in an aqueous environment, forming substituted thiazinane carboxylic acids. This report provides evidence that Hcy/HTL and formaldehyde (FA) adduct, namely 1,3-thiazinane-4-carboxylic acid (TCA) is formed in vivo in humans. In order to provide definitive proof, a gas chromatography–mass spectrometry (GC–MS) based method was elaborated to identify and quantify TCA in human urine. The GC–MS assay involves chemical derivatization with isobutyl chloroformate (IBCF) in the presence of pyridine as a catalyst, followed by an ethyl acetate extraction of the obtained isobutyl derivative of TCA (TCA-IBCF). The validity of the method has been demonstrated based upon United States Food and Drug Administration recommendations. The assay linearity was observed within a 1–50 µmol L−1 range for TCA in urine, while the lowest concentration on the calibration curve was recognized as the limit of quantification (LOQ). Importantly, the method was successfully applied to urine samples delivered by apparently healthy volunteers (n = 15). The GC–MS assay may provide a new analytical tool for routine clinical analysis of the role of TCA in living systems in the near future.

scholarly journals Preparation of mixed trialkyl alkylcarbonate derivatives of etidronic acid via an unusual route

2012 ◽  
Vol 8 ◽  
pp. 2019-2024 ◽  
Author(s):  
Petri A Turhanen ◽  
Janne Weisell ◽  
Jouko J Vepsäläinen
Keyword(s):  
Reaction Mechanism ◽  
Intermediate Product ◽  
Etidronic Acid ◽  
Spectroscopic Techniques ◽  
Isobutyl Chloroformate ◽  
Stable Intermediate ◽  
Lower Temperature ◽  
Derivatives Of

A method to prepare four (3a–d) trialkyl alkylcarbonate esters of etidronate from P,P'-dimethyl etidronate and alkyl chloroformate was developed by utilizing unexpected demethylation and decarboxylation reactions. The reaction with the sterically more hindered isobutyl chloroformate at a lower temperature (90 °C) produced the P,P'-diester (2) as a stable intermediate product. A possible reaction mechanism is discussed to explain these methyl substitutions. These unusual reactions also clarify why it is difficult to prepare alkylcarbonate prodrugs from bisphosphonates. The compounds prepared were analysed by spectroscopic techniques.

scholarly journals Kinetic evaluation of the solvolysis of isobutyl chloro- and chlorothioformate esters

2011 ◽  
Vol 7 ◽  
pp. 543-552 ◽  
Author(s):  
Malcolm J D’Souza ◽  
Matthew J McAneny ◽  
Dennis N Kevill ◽  
Jin Burm Kyong ◽  
Song Hee Choi
Keyword(s):  
Linear Free Energy Relationship ◽  
Previous Suggestion ◽  
Isobutyl Chloroformate ◽  
Pure Ethanol ◽  
Kinetic Evaluation ◽  
Organic Mixtures ◽  
First Order ◽  
Ionization Mechanisms ◽  
Linear Free Energy ◽  
Different Temperatures

The specific rates of solvolysis of isobutyl chloroformate (1) are reported at 40.0 °C and those for isobutyl chlorothioformate (2) are reported at 25.0 °C, in a variety of pure and binary aqueous organic mixtures with wide ranging nucleophilicity and ionizing power. For 1, we also report the first-order rate constants determined at different temperatures in pure ethanol (EtOH), methanol (MeOH), 80% EtOH, and in both 97% and 70% 2,2,2-trifluoroethanol (TFE). The enthalpy (ΔH≠) and entropy (ΔS≠) of activation values obtained from Arrhenius plots for 1 in these five solvents are reported. The specific rates of solvolysis were analyzed using the extended Grunwald–Winstein equation. Results obtained from correlation analysis using this linear free energy relationship (LFER) reinforce our previous suggestion that side-by-side addition–elimination and ionization mechanisms operate, and the relative importance is dependent on the type of chloro- or chlorothioformate substrate and the solvent.

Isobutyl chloroformate

2006 ◽  
Author(s):  
Tse-Lok Ho ◽  
Mary Fieser ◽  
Louis Fieser
Keyword(s):  
Isobutyl Chloroformate
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