Glycolide

Glycolic acid

Names
IUPAC name 2-Hydroxyethanoic acid
Other names dicarbonous acid glycolic acid hydroxyacetic acid hydroacetic acid
Identifiers
CAS Number	79-14-1 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:17497 Y
ChemSpider	737 Y
DrugBank	DB03085 Y
ECHA InfoCard	100.001.073
KEGG	C00160 N
PubChem CID	757
RTECS number	MC5250000
UNII	0WT12SX38S Y
InChI InChI=1S/C2H4O3/c3-1-2(4)5/h3H,1H2,(H,4,5) Y Key: AEMRFAOFKBGASW-UHFFFAOYSA-N Y InChI=1/C2H4O3/c3-1-2(4)5/h3H,1H2,(H,4,5) Key: AEMRFAOFKBGASW-UHFFFAOYAR
SMILES C(C(=O)O)O
Properties
Chemical formula	C2H4O3
Molar mass	76.05 g/mol
Appearance	white, powdery solid
Density	1.49 g/cm3
Melting point	75 °C (167 °F; 348 K)
Boiling point	decomposes
Solubility in water	70% solution
Solubility in other solvents	alcohols, acetone, acetic acid and ethyl acetate
Acidity (pKa)	3.83
Hazards
Main hazards	Corrosive (C)
R-phrases (outdated)	R22-R34
S-phrases (outdated)	S26-S36/37/39-S45
NFPA 704	1 3
Flash point	129 °C (264 °F; 402 K)
Related compounds
Related α-hydroxy acids	Lactic acid
Related compounds	Glycolaldehyde Acetic acid Glycerol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Glycolic acid (hydroacetic acid or hydroxyacetic acid); chemical formula C₂H₄O₃ (also written as HOCH₂CO₂H), is the smallest α-hydroxy acid (AHA). This colorless, odorless, and hygroscopic crystalline solid is highly soluble in water. It is used in various skin-care products. Glycolic acid is found in some sugar-crops. A glycolate or glycollate is a salt or ester of glycolic acid.

The name "glycolic acid" was coined in 1848 by French chemist Auguste Laurent (1807–1853). He proposed that the amino acid glycine — which was then called glycocolle — might be the amine of a hypothetical acid, which he called "glycolic acid" (acide glycolique).

Glycolic acid was first prepared in 1851 by German chemist Adolph Strecker (1822–1871) and Russian chemist Nikolai Nikolaevich Sokolov (1826–1877). They produced it by a treating hippuric acid with nitric acid and nitrogen dioxide to form an ester of benzoic acid and glycolic acid (C₆H₅C(=O)OCH₂COOH), which they called "benzoglycolic acid" (Benzoglykolsäure), (also benzoyl glycolic acid). They boiled the ester for days with dilute sulfuric acid, thereby obtaining benzoic acid and glycolic acid (Glykolsäure).

Glycolic acid can be synthesized in various ways. The predominant approaches uses a catalyzed reaction of formaldehyde with synthesis gas (carbonylation of formaldehyde), for its low cost.