Cargando…

Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation

Rapid synthesis of 4-ethyloctanoic acid by means of microwave irradiation is described. Diethyl malonate reacted with 2-ethyl-1-bromohexane in the presence of sodium ethoxide to give diethyl (2-ethylhexyl)malonate (1b). 1b was saponified in the solution of ethanol and potassium hydroxide and then ac...

Descripción completa

Detalles Bibliográficos
Autores principales: Liu, Yu-Ping, Yin, De-Cai, Chen, Hai-Tao, Sun, Bao-Guo
Formato: Texto
Lenguaje:English
Publicado: Molecular Diversity Preservation International (MDPI) 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2996780/
https://www.ncbi.nlm.nih.gov/pubmed/21152328
http://dx.doi.org/10.3390/ijms11104165
_version_ 1782193224185544704
author Liu, Yu-Ping
Yin, De-Cai
Chen, Hai-Tao
Sun, Bao-Guo
author_facet Liu, Yu-Ping
Yin, De-Cai
Chen, Hai-Tao
Sun, Bao-Guo
author_sort Liu, Yu-Ping
collection PubMed
description Rapid synthesis of 4-ethyloctanoic acid by means of microwave irradiation is described. Diethyl malonate reacted with 2-ethyl-1-bromohexane in the presence of sodium ethoxide to give diethyl (2-ethylhexyl)malonate (1b). 1b was saponified in the solution of ethanol and potassium hydroxide and then acidified to form (2-ethylhexyl)propanedioic acid (1c), and 1c was heated and decarboxylized to give 4-ethyloctanoic acid (1d). The influence of reaction temperature and reaction time on the yield of 1b and the effect of reaction time on the yield of 1c and 1d were investigated in order to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 1b were a mole ratio of sodium to diethyl malonate to 2-ethylhexyl bromide of 0.1:0.11:0.11, a reaction temperature of 80–85 °C, and a reaction time of 2–2.5 h. The yield of 1b was about 79%. 1b was saponified for 30 min and then acidified to form 1c, and the yield of 1c was 96%. 1c was heated for 16 min at 180°C to give 1d, and the yield of 1d was about 90%. The overall yield of 1d is 70% under microwave irradiation. The reaction time was reduced greatly. In order to compare the result of microwave irradiation with that of an oil bath, the reactions were also performed in an oil bath. The structures of intermediates, product and by-product were confirmed by HRMS, (1)H NMR, (13)C-NMR and IR.
format Text
id pubmed-2996780
institution National Center for Biotechnology Information
language English
publishDate 2010
publisher Molecular Diversity Preservation International (MDPI)
record_format MEDLINE/PubMed
spelling pubmed-29967802010-12-08 Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation Liu, Yu-Ping Yin, De-Cai Chen, Hai-Tao Sun, Bao-Guo Int J Mol Sci Article Rapid synthesis of 4-ethyloctanoic acid by means of microwave irradiation is described. Diethyl malonate reacted with 2-ethyl-1-bromohexane in the presence of sodium ethoxide to give diethyl (2-ethylhexyl)malonate (1b). 1b was saponified in the solution of ethanol and potassium hydroxide and then acidified to form (2-ethylhexyl)propanedioic acid (1c), and 1c was heated and decarboxylized to give 4-ethyloctanoic acid (1d). The influence of reaction temperature and reaction time on the yield of 1b and the effect of reaction time on the yield of 1c and 1d were investigated in order to optimize the synthetic conditions. The relative optimal conditions for the synthesis of 1b were a mole ratio of sodium to diethyl malonate to 2-ethylhexyl bromide of 0.1:0.11:0.11, a reaction temperature of 80–85 °C, and a reaction time of 2–2.5 h. The yield of 1b was about 79%. 1b was saponified for 30 min and then acidified to form 1c, and the yield of 1c was 96%. 1c was heated for 16 min at 180°C to give 1d, and the yield of 1d was about 90%. The overall yield of 1d is 70% under microwave irradiation. The reaction time was reduced greatly. In order to compare the result of microwave irradiation with that of an oil bath, the reactions were also performed in an oil bath. The structures of intermediates, product and by-product were confirmed by HRMS, (1)H NMR, (13)C-NMR and IR. Molecular Diversity Preservation International (MDPI) 2010-10-25 /pmc/articles/PMC2996780/ /pubmed/21152328 http://dx.doi.org/10.3390/ijms11104165 Text en © 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0 This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Liu, Yu-Ping
Yin, De-Cai
Chen, Hai-Tao
Sun, Bao-Guo
Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title_full Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title_fullStr Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title_full_unstemmed Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title_short Rapid Synthesis of Flavor Compound 4-Ethyloctanoic Acid under Microwave Irradiation
title_sort rapid synthesis of flavor compound 4-ethyloctanoic acid under microwave irradiation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2996780/
https://www.ncbi.nlm.nih.gov/pubmed/21152328
http://dx.doi.org/10.3390/ijms11104165
work_keys_str_mv AT liuyuping rapidsynthesisofflavorcompound4ethyloctanoicacidundermicrowaveirradiation
AT yindecai rapidsynthesisofflavorcompound4ethyloctanoicacidundermicrowaveirradiation
AT chenhaitao rapidsynthesisofflavorcompound4ethyloctanoicacidundermicrowaveirradiation
AT sunbaoguo rapidsynthesisofflavorcompound4ethyloctanoicacidundermicrowaveirradiation