Title: Crotonaldehyde
CAS Registry Number: 4170-30-3
CAS Name: 2-Butenal
Additional Names: crotonic aldehyde; b-methylacrolein
Molecular Formula: C4H6O
Molecular Weight: 70.09
Percent Composition: C 68.54%, H 8.63%, O 22.83%
Line Formula: CH3CH=CHCHO
Literature References: Commercial product is a 95:5 mixture of trans:cis isomers. Prepn: v. Auwers, Eisenlohr, J. Prakt. Chem. 82, 115 (1910); Hibbert, J. Am. Chem. Soc. 37, 1759 (1915). Alternate synthesis: J. Smidt et al., Angew. Chem. 71, 176 (1959). Toxicity studies: H. F. Smyth, C. P. Carpenter, J. Ind. Hyg. Toxicol. 26, 269 (1944). Review of use in commercial processes: O. Horn, Ind. Eng. Chem. 51, 655-658 (1959). Reviews: J. E. Fernandez, T. W. G. Solomons, Chem. Rev. 62, 485-502 (1962); W. Blau et al., in Ullmann's Encyclopedia of Industrial Chemistry vol. A8 (VCH, Weinheim, 5th ed., 1987) pp 83-89. Review of carcinogenic potential: V. J. Feron et al., Mutat. Res. 259, 363-385 (1991); of role in DNA adduct formation: S. S. Hecht et al., Toxicology 166, 31-36 (2001).
Properties: Flammable liq. Lacrimator! mp -69°; bp 102.2°; d2020 0.853; nD17.3 1.4384. Flash pt when anhydr: 13°C (55°F) (open cup). Explosive limits in air 2.95-15.5% v/v. Vapor density 2.41 (air = 1). Heat capacity: 0.7 cal/g/°C; heat of vaporization: 123 cal/g. Dimerizes under strong acid conditions, slowly oxidizes to crotonic acid. Soly in water (g/100 g) at 20°: 18.1; at 5°: 19.2. Soly of water in crotonaldehyde (g/100 g) at 20°: 9.5; at 5°: 8.0. LD50 orally in rats: 0.3 g/kg (Smyth, Carpenter).
Melting point: mp -69°
Boiling point: bp 102.2°
Flash point: Flash pt when anhydr: 13°C (55°F) (open cup)
Index of refraction: nD17.3 1.4384
Density: d2020 0.853
Toxicity data: LD50 orally in rats: 0.3 g/kg (Smyth, Carpenter)
CAUTION: Potential symptoms of overexposure are irritation of eyes and respiratory system. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 80.
Use: Manuf of butyl alcohol, butyraldehyde, methoxybutyraldehyde, sorbic acid, maleic acid, crotonic acid, crotyl alcohol. In polymer chemistry: manuf of resins and polyvinyl acetals, solvent for polyvinyl chloride, rubber antioxidant, increases rubber strength with ketones. In prepn of insecticides and fertilizers. In production of flavors. |