87122-97-2Relevant academic research and scientific papers
Investigation of the synthetic and mechanistic aspects of the highly stereoselective transformation of α-thioamides to α-thio-β- chloroacrylamides
Murphy, Maureen,Lynch, Denis,Schaeffer, Marcel,Kissane, Marie,Chopra, Jay,O'Brien, Elisabeth,Ford, Alan,Ferguson, George,Maguire, Anita R.
, p. 1228 - 1241 (2008/02/03)
Treatment of a series of α-thioamides with N-chlorosuccinimide results in efficient transformation to the analogous α-thio-β- chloroacrylamides. The mechanistic pathway has been established through isolation and characterisation of intermediate compounds. The scope of the transformation has been explored - aryl and alkylthio substituents, primary, secondary and tertiary amides can be employed. In most instances, the chloroacrylamides are formed exclusively as the Z-stereoisomer; however, with tertiary propanamides or with amides derived from butanoic or pentanoic acid a mixture of E- and Z-stereoisomers is formed. The Royal Society of Chemistry.
Mass Spectrometry of 2-Alkylthio-2-methylpropanoic Acids and Their Esters and Amides. Structural and Steric Effects on the McLafferty Rearrangement
Mori, Yuji,Fujiwara, Shigeru,Miyachi, Toshiko,Kitanishi, Hiroyuki,Oya, Masayuki,et al.
, p. 1505 - 1517 (2007/10/02)
The electron ionization mass spectra (MS) of S-methylated derivatives of N-(2-mercapto-2-methylpropanoyl)-L-cysteine and 2-alkylthio-2-methylpropanoic acids, as well as their esters and amides, were examined.Use of the deuterium labeling technique and accurate mass measurement supported the proposed fragmentation pathways.Extensive loss of CH2S from a molecular ion by the McLafferty rearrangementof a primary hydrogen is important in the MS of S-methyl compounds of amide derivatives.It was demonstrated that the intensity of the rearrangement ion decreases in the order of amide, ester, and acid, and in the case if amides the reaarangement is suppressed by the nonbonded interaction between methyl groups on the α carbon and the amide nitrogen.Keywords-N-(2-mercapto-2-methylpropanoyl)-L-cysteine; 2-alkylthio-2-methylpropanoic acid and methyl ester; 2-alkylthio-2-methylpropanamide; electron impact mass spectrometry; McLafferty rearrangement; steric interaction
