Title: b-Propiolactone
CAS Registry Number: 57-57-8
CAS Name: 2-Oxetanone
Additional Names: hydracrylic acid b-lactone; b-propionolactone; propanolide
Manufacturers' Codes: NSC-21626
Trademarks: Betaprone (Forest)
Molecular Formula: C3H4O2
Molecular Weight: 72.06
Percent Composition: C 50.00%, H 5.60%, O 44.41%
Literature References: Prepd by the condensation of ketene with formaldehyde: Küng, US 2356459 (1941). Purification: Gresham, Jansen, US 2602802 (1952 to B. F. Goodrich). Use in Diels-Alder diene synthesis: Gresham et al., J. Am. Chem. Soc. 76, 609 (1954). Review of carcinogenic risk: IARC Monographs 4, 259-269 (1974).
Properties: Liquid. d420 1.1460; d425 1.1420; d2020 1.1490. mp -33.4°. bp760 162° (dec); bp750 150° (dec); bp20 61°; bp10 51°. Flash pt 70°C (158°F). nD20 1.4131; nD25 1.4110. Dipole moment 3.8. Slowly hydrolyzed to hydracrylic acid. Stable when stored at 5° in glass containers. Soly in water: 37% v/v. Misc with alcohol, acetone, ether, chloroform.
Melting point: mp -33.4°
Boiling point: bp760 162° (dec); bp750 150° (dec); bp20 61°; bp10 51°
Flash point: Flash pt 70°C (158°F)
Index of refraction: nD20 1.4131; nD25 1.4110
Density: d420 1.1460; d425 1.1420; d2020 1.1490
CAUTION: Potential symptoms of overexposure are skin irritation, blistering and burns; corneal opacity; frequent urination; dysuria; hematuria. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 264. This substance is reasonably anticipated to be a human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-225.
Use: Versatile intermediate in organic synthesis.
Therap-Cat: Disinfectant.
Keywords: Antiseptic/Disinfectant.
beta-Resorcylaldehyde beta-Resorcylic Acid beta-Santalol Betasine beta-Sitosterol

Skeletal formula
Balla-and-stick model
CAS number 57-57-8 YesY
ChemSpider 2275 YesY
KEGG D05630 YesY
ChEBI CHEBI:49073 YesY
Jmol-3D images Image 1
Molecular formula C3H4O2
Molar mass 72.06 g mol−1
Appearance Colorless liquid
Odor Pungent, acrylic
Density 1.146 g/cm3
Melting point −33.4 °C; −28.1 °F; 239.8 K
Boiling point 162 °C; 324 °F; 435 K (dec.)
Solubility in water Soluble
Solubility in organic solvents Miscible
Refractive index (nD) 1.4131
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

β-Propiolactone is an organic compound of the lactone family, with a four-membered ring. It is a clear, colorless liquid with a slightly sweet odor, highly soluble in water and miscible with ethanol, acetone, diethyl ether and chloroform.[1][2] The word propiolactone usually refers to this compound, although it may also refer to α-propiolactone.

β-Propiolactone is "reasonably expected to be a human carcinogen" (IARC, 1999).[1] It is one of 13 "OSHA-regulated carcinogens," chemicals regarded occupational carcinogens by the Occupational Safety and Health Administration, despite not having an established permissible exposure limit.[3] It was once widely used in the manufacture of acrylic acid and its esters, but its use has been mostly phased out in favor of safer and less expensive alternatives. β-Propiolactone is a disinfectant and has been used to sterilize blood plasma, vaccines, tissue grafts, surgical instruments, and enzymes.[1] The principal current use of propiolactone is an intermediate in the synthesis of other chemical compounds.

β-Propiolactone will slowly react with water and hydrolyze to produce 3-hydroxypropionic acid (hydracryclic acid).