Title: Cyclopropane
CAS Registry Number: 75-19-4
Additional Names: Trimethylene
Molecular Formula: C3H6
Molecular Weight: 42.08
Percent Composition: C 85.63%, H 14.37%
Literature References: Prepd by reduction of 1,2-dibromocyclopropane with zinc and alcohol: Lott, Christiansen, J. Am. Pharm. Assoc. 19, 341 (1930); Schlatter, J. Am. Chem. Soc. 63, 1733 (1941); from 1,3-dibromopropane with zinc and alcohol in absence of water: Ashdown et al., ibid. 58, 850 (1936); by the action of sodium vapor on 1,3-dibromopropane: Bawn, Hunter, Trans. Faraday Soc. 34, 608 (1938); from 1,3-dichloropropane heated with an excess of zinc dust, iodine and ethanol in 80% yield: Hass et al., Ind. Eng. Chem. 28, 1178 (1936); from 1,3-dichloropropane with zinc in presence of sodium iodide: US 2102556 (1937); cf. US 2098239; GB 498225; US 2211787; US 2235679; US 2235762; US 2240513; US 2240514; US 2242235. From ethylene by the reaction with methylene iodide and a zinc-copper couple in 29% yield: Simmons, Smith, J. Am. Chem. Soc. 80, 5323 (1958); Chem. Eng. News 36, 40 (Dec 8, 1958).
Properties: Flammable gas. Characteristic odor resembling that of petr ether. mp -127°. bp -33°. Liquefies at 4-6 atms. One liter of cyclopropane (at 1 atm, 0°) weighs 1.879 g. One vol of cyclopropane dissolves in about 2.7 vols of water at 15°. Freely sol in alcohol, ether. Sol in fixed oils. Concd H2SO4 absorbs the gas readily.
Melting point: mp -127°
Boiling point: bp -33°
CAUTION: Mixture of cyclopropane with oxygen or air may explode when brought in contact with a flame or other causes of ignition. Explosive limits (% by vol in air), lower: 2.41; upper: 10.3. The explosibility is greater than that of other anesthetic-oxygen mixtures because of the comparatively larger amounts of oxygen that are compatible with cyclopropane anesthesia. Rich oxygen mixtures are therefore to be avoided.
Therap-Cat: Anesthetic (inhalation).
Therap-Cat-Vet: Anesthetic (inhalation).
Keywords: Anesthetic (Inhalation).
Cyclopropyl Methyl Ether Cyclorphan Cycloserine Cyclosporins Cyclotheonamides

Cyclopropane - displayed formula Cyclopropane - skeletal formula
Cyclopropane-3D-balls.png Cyclopropane-3D-vdW.png
CAS number 75-19-4 YesY
PubChem 6351
ChemSpider 6111 YesY
UNII 99TB643425 YesY
KEGG D03627 YesY
ChEBI CHEBI:30365 YesY
Jmol-3D images Image 1
Molecular formula C3H6
Molar mass 42.08 g/mol
Density 1.879 g/L (1 atm, 0 °C)
Melting point −128 °C; −198 °F; 145 K
Boiling point −33 °C; −27 °F; 240 K
Acidity (pKa) ~46
MSDS External MSDS
Main hazards Highly flammable
NFPA 704
NFPA 704.svg
 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

Cyclopropane is a cycloalkane molecule with the molecular formula C3H6, consisting of three carbon atoms linked to each other to form a ring, with each carbon atom bearing two hydrogen atoms resulting in D3h molecular symmetry. Cyclopropane and propene have the same molecular formula but have different structures, making them structural isomers.

Cyclopropane is an anaesthetic when inhaled. In modern anaesthetic practice, it has been superseded by other agents, due to its extreme reactivity under normal conditions: When the gas is mixed with oxygen there is a significant risk of explosion.