Next Article in Journal
A Novel Soluble Tin(IV) Porphyrin Modified Single-Walled Carbon Nanotube Nanohybrid With Light Harvesting Properties
Next Article in Special Issue
Supported Phospholipid Bilayer Interaction with Components Found in Typical Room-Temperature Ionic Liquids – a QCM-D and AFM Study
Previous Article in Journal
Preparation, GIAO NMR Calculations and Acidic Properties of Some Novel 4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives with Their Antioxidant Activities
Previous Article in Special Issue
Laser photolysis study of anthraquinone in binary mixtures ofionic liquid [bmim][PF6] and organic solvent
Int. J. Mol. Sci. 2008, 9(1), 33-44; doi:10.3390/ijms9010033
Article

Microwave-Assisted Esterification of N-Acetyl-L-Phenylalanine Using Modified Mukaiyama’s Reagents: A New Approach Involving Ionic Liquids

* , ,  and
Received: 30 November 2007; Accepted: 10 January 2008 / Published: 16 January 2008
(This article belongs to the Special Issue Ionic Liquids)
Download PDF [237 KB, uploaded 19 June 2014]
Abstract: Inspired by the concept of ionic liquids (ILs), this study modified the original Mukaiyama’s reagent, 2-chloro-1-methylpyridinium iodide (m.p. 200-dec), from ionic solid into liquids by changing its anion. The esterification of N-acetyl-L-phenylalanine was investigated as a model reaction. The microwave irradiation was more effective in esterifying N-acetyl-L-phenylalanine than the conventional reflux method. The original Mukaiyama’s reagent was modified into ILs through manipulating its anion. However, only non-nucleophilic anions (such as EtSO4- and Tf2N-) were favorable since nucleophilic ones (such as CF3COO- and CH3COO-) could exchange with chlorine resulting in non-reactive coupling reagents. Two modified Mukaiyama’s compounds (i.e. hydrophilic [2- ClMePy][EtSO4] and hydrophobic [2-ClMePy][Tf2N]) have been identified as the best ILtype coupling reagents. The esterification reaction was greatly enhanced by using 1- methylimidazole as the base instead of conventional toxic tertiary amines, and by using excess amount of alcohols as solvents instead of dichloromethane. Overall, the method reported is effective and ‘greener’.
Keywords: amino acid; ionic liquid; Mukaiyama’s reagent; microwave; esterification. amino acid; ionic liquid; Mukaiyama’s reagent; microwave; esterification.
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Export to BibTeX |
EndNote


MDPI and ACS Style

Zhao, H.; Song, Z.; Cowins, J.V.; Olubajo, O. Microwave-Assisted Esterification of N-Acetyl-L-Phenylalanine Using Modified Mukaiyama’s Reagents: A New Approach Involving Ionic Liquids. Int. J. Mol. Sci. 2008, 9, 33-44.

AMA Style

Zhao H, Song Z, Cowins JV, Olubajo O. Microwave-Assisted Esterification of N-Acetyl-L-Phenylalanine Using Modified Mukaiyama’s Reagents: A New Approach Involving Ionic Liquids. International Journal of Molecular Sciences. 2008; 9(1):33-44.

Chicago/Turabian Style

Zhao, Hua; Song, Zhiyan; Cowins, Janet V.; Olubajo, Olarongbe. 2008. "Microwave-Assisted Esterification of N-Acetyl-L-Phenylalanine Using Modified Mukaiyama’s Reagents: A New Approach Involving Ionic Liquids." Int. J. Mol. Sci. 9, no. 1: 33-44.


Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert