3-Hydroxypropionic acid

3-Hydroxypropionic acid is a carboxylic acid, specifically a beta hydroxy acid. It is an acidic viscous liquid with a pKa of 4.9.^[2] It is very soluble in water, soluble in ethanol and diethyl ether. Upon distillation, it dehydrates to form acrylic acid, and is occasionally called hydracrylic acid

3-Hydroxypropionic acid^[1]

Names
Preferred IUPAC name 3-Hydroxypropanoic acid
Other names 3-Hydroxypropionic acid Hydracrylic acid Ethylene lactic acid
Identifiers
CAS Number	503-66-2 Y
3D model (JSmol)	Interactive image
Beilstein Reference	773806
ChEBI	CHEBI:33404 Y
ChEMBL	ChEMBL1205969
ChemSpider	61460 Y
DrugBank	DB03688 Y
ECHA InfoCard	100.007.250
EC Number	207-974-8
KEGG	C01013 Y
PubChem CID	68152
UNII	C4ZF6XLD2X
CompTox Dashboard (EPA)	DTXSID50198305
InChI InChI=1S/C3H6O3/c4-2-1-3(5)6/h4H,1-2H2,(H,5,6) Y Key: ALRHLSYJTWAHJZ-UHFFFAOYSA-N Y InChI=1/C3H6O3/c4-2-1-3(5)6/h4H,1-2H2,(H,5,6) Key: ALRHLSYJTWAHJZ-UHFFFAOYAU
SMILES O=C(O)CCO
Properties
Chemical formula	C3H6O3
Molar mass	90.08 g/mol
Melting point	<25 °C 143 °C (sodium salt)
Boiling point	Decomposes
Solubility in water	Very soluble
Acidity (pKa)	4.87[2]
Related compounds
Related carboxylic acids	acetic acid glycolic acid propionic acid lactic acid malonic acid butyric acid hydroxybutyric acid
Related compounds	1-propanol 2-propanol propionaldehyde acrolein
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

3-Hydroxypropionic acid is used in the industrial production of various chemicals such as acrylates.

Synthesis

3-Hydroxypropionic acid can be obtained by base-induced hydration of acrylic acid followed by reacidification. Another synthesis involves cyanation of ethylene chlorohydrin followed by hydrolysis of the resulting nitrile. Hydrolysis of propiolactone is yet another route.^[3] Propiolactone, the dehydrated derivative of 3-hydroxypropionic acid, is produced by reaction of ketene and formaldehyde.^[4]

3-Hydroxypropionic acid is listed as one of the "top" chemicals that could be produced from renewable resources. In particular, it could be produced by manipulation of glycerol, but this technology has not reached a commercial stage.^[5] It can also be produced from glucose via pyruvate and malonyl coenzyme A.^[4][6]

Potential applications

3-Hydroxypropionic acid is of interest as a bio-derived precursor to acrylic acid.^[5]

The polyester poly(3-hydroxypropionic acid) is a biodegradable polymer.^[7] The method combines the high-molecular weight and control aspects of ring-opening polymerization with the commercial availability of the beta hydroxy acid, 3-hydroxypropionic acid which is abbreviated as 3-HP. Since 3-HPA can be derived from biological sources, the resulting material, poly(3-hydroxypropionic acid) or P(3-HPA), is biorenewable.

Genetically encoded 3-hydroxypropionic acid inducible system

3-Hydroxypropionic acid can be produced by engineered microbes.^[8]

A genetically encoded 3-hydroxypropionic acid inducible system has been characterized in bacteria demonstrating that such system in combination with fluorescent reporter protein can be utilized as a biosensor to measure intracellular and extracellular 3-HP concentrations by fluorescence output.^[9]

See also

• Lactic acid (2-hydroxypropanoic acid)
• listed as hydracrylic acid in the Merck index, 12th Edition

References

1. Merck Index, 11th Edition, 4681.
2. Handbook of Chemistry and Physics, CRC press, 58th edition page D150-151 (1977)
3. Miltenberger, Karlheinz (2000). "Hydroxycarboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_507. ISBN 3527306730.
4. Mika, László T.; Cséfalvay, Edit; Németh, Áron (2018). "Catalytic Conversion of Carbohydrates to Initial Platform Chemicals: Chemistry and Sustainability". Chemical Reviews. 118 (2): 505–613. doi:10.1021/acs.chemrev.7b00395. PMID 29155579.
5. Bozell, Joseph J.; Petersen, Gene R. (2010). "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. doi:10.1039/b922014c.
6. Liu, Changshui; Ding, Yamei; Xian, Mo; Liu, Min; Liu, Huizhou; Ma, Qingjun; Zhao, Guang (2017). "Malonyl-CoA pathway: A promising route for 3-hydroxypropionate biosynthesis". Critical Reviews in Biotechnology. 37 (7): 933–941. doi:10.1080/07388551.2016.1272093. PMID 28078904.
7. "3-HP". Retrieved 27 May 2011.
8. "Scientists Engineer Extreme Microorganisms to Make Fuel from Atmospheric Carbon Dioxide". 27 March 2013.
9. Hanko, E.K.R.; Minton, N.P.; Malys, N. (2017). "Characterisation of a 3-hydroxypropionic acid-inducible system from Pseudomonas putida for orthogonal gene expression control in Escherichia coli and Cupriavidus necator". Scientific Reports. 7 (1724): 1724. Bibcode:2017NatSR...7.1724H. doi:10.1038/s41598-017-01850-w. PMC 5431877. PMID 28496205.

External links

• Chisholm, Hugh, ed. (1911). "Hydracrylic Acid" . Encyclopædia Britannica. Vol. 14 (11th ed.). Cambridge University Press. p. 34.