Propiolic acid

Propiolic acid

Names
Preferred IUPAC name Prop-2-ynoic acid [1]
Other names Propiolic acid Acetylene carboxylic acid Propargylic acid Acetylene mono-carboxylic acid
Identifiers
CAS Number	471-25-0  Y
3D model (JSmol)	Interactive image
Beilstein Reference	878176
ChEBI	CHEBI:33199  Y
ChEMBL	ChEMBL1213530  Y
ChemSpider	9706  N
ECHA InfoCard	100.006.763
EC Number	207-437-8
Gmelin Reference	81893
KEGG	C00804  Y
MeSH	C011537
PubChem CID	10110
UNII	P2QW39G9LZ  Y
CompTox Dashboard (EPA)	DTXSID6060050
InChI InChI=1S/C3H2O2/c1-2-3(4)5/h1H,(H,4,5) N Key: UORVCLMRJXCDCP-UHFFFAOYSA-N N InChI=1/C3H2O2/c1-2-3(4)5/h1H,(H,4,5) Key: UORVCLMRJXCDCP-UHFFFAOYAX
SMILES C#CC(=O)O
Properties
Chemical formula	C3H2O2
Molar mass	70.047 g·mol−1
Density	1.1325 g/cm3
Melting point	9 °C (48 °F; 282 K)
Boiling point	144 °C (291 °F; 417 K) (decomposes)
Acidity (pKa)	pka = 1.89 [2]
Hazards
GHS labelling: [3]
Pictograms
Signal word	Danger
Hazard statements	H226, H301, H310, H315, H335
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P262, P264, P270, P271, P280, P301+P310, P302+P350, P302+P352, P303+P361+P353, P304+P340, P310, P312, P321, P322, P330, P332+P313, P361, P362, P363, P370+P378, P403+P233, P403+P235, P405, P501
Safety data sheet (SDS)	External MSDS
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

Propiolic acid is the organic compound with the formula HC₂CO₂H. It is the simplest acetylenic carboxylic acid. It is a colourless liquid that crystallises to give silky crystals. Near its boiling point, it decomposes.

It is soluble in water and possesses an odor like that of acetic acid. ^{[4] [5]}

Preparation

It is prepared commercially by oxidizing propargyl alcohol at a lead electrode. ^[6] It can also be prepared by decarboxylation of acetylenedicarboxylic acid.^{[ citation needed ]}

Reactions and applications

Exposure to sunlight converts it into trimesic acid (benzene-1,3,5-tricarboxylic acid). ^[5] It undergoes bromination to give dibromoacrylic acid. With hydrogen chloride it forms chloroacrylic acid. Its ethyl ester condenses with hydrazine to form pyrazolone. ^[5]

It forms a characteristic explosive solid upon treatment to its aqueous solution with ammoniacal silver nitrate. ^[5] An amorphous explosive precipitate forms with ammoniacal cuprous chloride.

Propiolates

Propiolates are esters or salts of propiolic acid. Common examples include methyl propiolate and ethyl propiolate.

See also

• Propargyl
• Propargyl alcohol

References

1. Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 748. doi:10.1039/9781849733069-FP001. ISBN   978-0-85404-182-4.
2. "Propiolic acid".
3. "Propiolic acid". pubchem.ncbi.nlm.nih.gov. Retrieved 16 December 2021.
4. ed, Susan Budavari (1990). The Merck index an encyclopedia of chemicals, drugs, and biologicals (11. ed., 2. print. ed.). Rahway, NJ: Merck. pp.  7833, 1911. ISBN   9780911910285.
5. Chisholm, Hugh, ed. (1911). "Propiolic Acid"  . Encyclopædia Britannica . Vol. 22 (11th ed.). Cambridge University Press. p. 449.
6. Wilhelm Riemenschneider (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN   3527306730.