Propionyl chloride

Propionyl chloride (also propanoyl chloride) is the organic compound with the formula CH₃CH₂C(O)Cl. It is the acyl chloride derivative of propionic acid. It undergoes the characteristic reactions of acyl chlorides.^[1] It is a colorless, corrosive, volatile liquid.

Propionyl chloride

Names
Preferred IUPAC name Propanoyl chloride
Other names Propionic chloride; propionic acid chloride (1:1)
Identifiers
CAS Number	79-03-8
3D model (JSmol)	Interactive image
ECHA InfoCard	100.001.064
PubChem CID	62324
UNII	MB6VL5OMB9
CompTox Dashboard (EPA)	DTXSID4058819
SMILES CCC(=O)Cl
Properties
Chemical formula	C3H5ClO
Molar mass	92.52 g·mol−1
Appearance	colorless liquid
Density	1.0646 g/cm3
Melting point	−94 °C (−137 °F; 179 K)
Boiling point	80 °C (176 °F; 353 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Corrosive, flammable; highly toxic
Flash point	54 °C (129 °F; 327 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	100 mg/kg (rat, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

It is used as a reagent for organic synthesis. In derived chiral amides and esters, the methylene protons are diastereotopic.^[2]

There have been efforts^[3] to schedule Propionyl chloride as a DEA List 1 Chemical as it can be used to synthesize fentanyl.

Synthesis

Propionyl chloride is industrially produced by chlorination of propionic acid with phosgene:^[4]

CH₃CH₂CO₂H + COCl₂ → CH₃CH₂COCl + HCl + CO₂

References

1. Michael B Smith (22 November 2016). Organic Synthesis. Elsevier Science. p. 165. ISBN 978-0-12-800807-2.
2. Gage, James R.; Evans, David A. (1990). "Diastereoselective Aldol Condensation Using a Chiral Oxazolidinone Auxiliary: (2S,3S)-3-Hydroxy-3-phenyl-2-methylpropanoic Acid". Org. Synth. 68: 83. doi:10.15227/orgsyn.068.0083.
3. https://www.federalregister.gov/documents/2023/10/12/2023-22570/propionyl-chloride
4. Samel, Ulf-Rainer; Kohler, Walter; Gamer, Armin Otto; Keuser, Ullrich (2005). "Propionic acid and derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_223. ISBN 978-3-527-30673-2.