Title: Ketene
CAS Registry Number: 463-51-4
CAS Name: Ethenone
Additional Names: carbomethene
Molecular Formula: C2H2O
Molecular Weight: 42.04
Percent Composition: C 57.14%, H 4.80%, O 38.06%
Line Formula: CH2=C=O
Literature References: Prepd by the thermal decompn of acetone, diketene or acetic anhydride: Hurd, Org. Synth. coll. vol. I, 330 (2nd ed., 1941); S. Andreades, H. D. Carlson, ibid. coll. vol. V, 679 (1973). Structure of ketene dimer as 3-buteno-b-lactone: Blomquist, Baldwin, J. Am. Chem. Soc. 70, 29 (1948); Hurd, Blanchard, ibid. 72, 1461 (1950); Katz, Lipscomb, J. Org. Chem. 17, 515 (1953). Toxicology: J. F. Treon et al., J. Ind. Hyg. Toxicol. 31, 209 (1949). Review on the prepn of stable ketenes: R. S. Ward in The Chemistry of Ketenes, Allenes and Related Compounds Part 1,, S. Patai, Ed. (Wiley, New York, 1980) pp 223-277; on synthetic uses of ketenes: W. T. Brady, ibid. pp 279-308.
Properties: Gas. Penetrating odor. mp -150°. bp -56°. Electron diffraction pictures: Beach, Stevenson, J. Chem. Phys. 6, 75 (1938). Fairly sol in acetone. All operations with ketene should be carried out in an efficient hood (Andreades, Carlson).
Melting point: mp -150°
Boiling point: bp -56°
CAUTION: Potential symptoms of overexposure are irritation of skin, eyes, nose, throat and respiratory system; pulmonary edema. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 184.
Use: For the conversion of higher acids into their anhydrides; for acetylation in the manuf of cellulose acetate and aspirin. |