2966. Diacetyl

Nomenclature

CAS number: 431-03-8
2,3-Butanedione; biacetyl; dimethyl diketone; dimethylglyoxal; 2,3-diketobutane.
C4H6O2; mol wt 86.09.
C 55.81%, H 7.02%, O 37.17%.
CH3COCOCH3.

Description and references

Found in bay and other oils; also in butter. Made from methyl ethyl ketone by converting to the isonitroso compd and then decomposing to diacetyl by hydrolysis with HCl; by special fermentation of glucose via methylacetylcarbinol: Suomalainen, J"annes, Nature 157, 336 (1946). Toxicity study: P. M. Jenner et al., Food Cosmet. Toxicol. 2, 327 (1964).

Properties

Yellowish-green liq; quinone odor; the vapors have a Cl-like odor. d1515 0.990. bp 88°. nD18 1.3933. Sol in ≈4 parts water; misc with alcohol, ether. LD50 orally in rats: 1580 mg/kg (Jenner).

Use

Carrier of aroma of butter, vinegar, coffee, and other foods.