Levulinic acid

Levulinic acid, or 4-oxopentanoic acid, is an organic compound with the formula CH₃C(O)CH₂CH₂CO₂H. It is classified as a keto acid. This white crystalline solid is soluble in water and polar organic solvents. It is derived from degradation of cellulose and is a potential precursor to biofuels,^[2] such as ethyl levulinate.^[3]

Levulinic acid^[1]

Names
Preferred IUPAC name 4-Oxopentanoic acid
Other names Levulinic acid, β-Acetylpropionic acid, 3-Acetopropionic acid, β-acetylpropionic acid, γ-ketovaleric acid
Identifiers
CAS Number	123-76-2 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:45630 Y
ChEMBL	ChEMBL1235931 N
ChemSpider	11091 Y
DrugBank	DB02239 Y
ECHA InfoCard	100.004.228
PubChem CID	11579
UNII	RYX5QG61EI Y
CompTox Dashboard (EPA)	DTXSID8021648
InChI InChI=1S/C5H8O3/c1-4(6)2-3-5(7)8/h2-3H2,1H3,(H,7,8) Y Key: JOOXCMJARBKPKM-UHFFFAOYSA-N Y InChI=1/C5H8O3/c1-4(6)2-3-5(7)8/h2-3H2,1H3,(H,7,8) Key: JOOXCMJARBKPKM-UHFFFAOYAR
SMILES CC(=O)CCC(=O)O
Properties
Chemical formula	C5H8O3
Molar mass	116.11 g/mol
Density	1.1447 g/cm3
Melting point	33 to 35 °C (91 to 95 °F; 306 to 308 K)
Boiling point	245 to 246 °C (473 to 475 °F; 518 to 519 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Synthesis

Levulinic acid was first prepared in 1840 by Dutch chemist Gerardus Johannes Mulder by heating fructose with hydrochloric acid.^[4] The first commercial production of levulinic acid began as a batchwise process in an autoclave by starch manufacturer A. E. Staley in the 1940s.^[5] In 1953 Quaker Oats developed a continuous process for the production of levulinic acid.^[6] In 1956 it was identified as a platform chemical with high potential.^[7] and in 2004 the US Department of Energy (U.S. DoE) identified levulinic acid as one of the 12 potential platform chemicals in the biorefinery concept.^[8]

The synthesis of levulinic acid from hexoses (glucose, fructose) or starch in dilute hydrochloric acid or sulfuric acid.^{[4][9][10][11]} In addition to formic acid further, partly insoluble, by-products are produced. These are deeply colored and their complete removal is a challenge for most technologies.

Many concepts for the commercial production of levulinic acid are based on a strong acid technology. The processes are conducted in a continuous manner at high pressures and temperatures. Lignocellulose is an inexpensive starting material. Levulinic acid is separated from the mineral acid catalyst by extraction. Levulinic acid is purified by distillation.^[12]

Reactions and applications

Levulinic acid is used as a precursor for pharmaceuticals, plasticizers, and various other additives.^[13] The largest application of levulinic acid is its use in the production of aminolevulinic acid, a biodegradable herbicide used in South Asia. Another key application is the use of levulinic acid in cosmetics. Ethyl levulinate, a primary derivative of levulinic acid, is extensively used in fragrances and perfumes. Levulinic acid is a chemical building block or starting material for a wide variety of other compounds^[14] including γ-valerolactone and 2-methyl-THF.^[8]

Other occurrence and niche uses

Levulinic acid is used in cigarettes to increase nicotine delivery in smoke and binding of nicotine to neural receptors.^[15]

Levulinic acid, in its cyclic alternate structure, was the first pseudoacid to be described as such.

Etymology

The former term “levulose” for fructose gave levulinic acid its name.

Safety

Levulinic acid is relatively nontoxic, with an LD₅₀ of 1850 mg/kg.^[13]

References

1. The Merck Index, 15th Ed. (2013), p. 1018, Monograph 5526, O'Neil: The Royal Society of Chemistry. Available online at: http://www.rsc.org/Merck-Index/monograph/mono1500005526
2. Biorefineries – Industrial Processes and Products. Status Quo and Future Directions. Vol. 1, Edited by Birgit Kamm, Patrick R. Gruber, Michael Kamm. 2006, WILEY-VCH, Weinheim. ISBN 3-527-31027-4
3. Leal Silva, Jean Felipe; Grekin, Rebecca; Mariano, Adriano Pinto; Maciel Filho, Rubens (2018). "Making Levulinic Acid and Ethyl Levulinate Economically Viable: A Worldwide Technoeconomic and Environmental Assessment of Possible Routes". Energy Technology. 6 (4): 613–639. doi:10.1002/ente.201700594. ISSN 2194-4296.
4. Mulder, G. J. (1840). "Untersuchungen über die Humussubstanzen" [Investigations on humic substances]. J. Prakt. Chem. (in German). 21 (1): 203–240. doi:10.1002/prac.18400210121.
5. A. E. Staley, Mfg. Co. (Decatur, Ill.); Levulinic Acid 1942 [C.A. 36, 1612]
6. U.S. patent 2,813,900
7. R. H. Leonard, Ind. Eng. Chem. 1331, (1956).
8. The Pacific Northwest National Laboratory and The National Renewable Energy Laboratory (Aug 2004). "Volume I-Results of Screening for Potential Candidates from Sugars and Synthesis Gas" (PDF). Top Value Added Chemicals from Biomass. U.S. Department of Energy.
9. A. Freiherrn, V. Grote, B. Tollens, "Untersuchungen über Kohlenhydrate. I. Ueber die bei Einwirkung von Schwefelsäure auf Zucker entstehende Säure (Levulinsäure)" Justus Liebigs Annalen der Chemie volume 175, pp. 181-204 (1875). doi:10.1002/jlac.18751750113
10. B. F. McKenzie (1941). "Levulinic acid". Organic Syntheses; Collected Volumes, vol. 1, p. 335.
11. S.L. Suib, New and Future Developments in Catalysis – Catalytic Biomass Conversion, Elsevier, (2013). ISBN 978-0-444-53878-9
12. U.S. patent 5,608,105
13. Franz Dietrich Klingler, Wolfgang Ebertz "Oxocarboxylic Acids" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a18_313
14. Bozell, Joseph J.; Petersen, Gene R. (2010-04-06). "Technology development for the production of biobased products from biorefinery carbohydrates—the US Department of Energy's "Top 10" revisited". Green Chemistry. 12 (4): 539–554. doi:10.1039/b922014c.
15. Doris Cullen et al., A Guide to Deciphering the Internal Codes Used by the Tobacco Industry, Report No. 03-05, Harvard School of Public Health, Division of Public Health Practice, Tobacco Research Program, August 2005, http://legacy.library.ucsf.edu/resources/harvard_monograph.pdf

• Dunstan, Wyndham Rowland (1911). "Rubber" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 23 (11th ed.). Cambridge University Press. p. 802.