2-Butanone

Community Right-To-Know List. EPA Genetic Toxicology Program. Reported in EPA TSCA Inventory.

OSHA PEL: TWA 200 ppm; STEL 300 ppm
ACGIH TLV: TWA 200 ppm; STEL 300 ppm; BEI: 2 mg(MEK)/L in urine at end of shift
DFG MAK: 200 ppm (600 mg/m³)
NIOSH REL: (Ketones) TWA 590 mg/m³
DOT Classification:  3; Label: Flammable Liquid

For occupational chemical analysis use OSHA: #16 or NIOSH: 2-Butanone, 2500.

2-Butanone, with the CAS register number 78-93-3, is an organic compound with the formula C₄H₈O. It can alo be called as Methyl ethyl ketone or MEK. 2-Butanone is colorless liquid ketone has a sharp, sweet odor which is soluble in water. In addition, it is stable and highly flammable, which is also incompatible with oxidizing agents, bases, strong reducing agents. However, 2-Butanone should be protected from moisture. 2-Butanone has the EINECS register number 201-159-0.

Properties: Because 2-Butanone has carbonyl group and activehydrogen connected with carbonyl, it is easy to produce many sorts of reaction. 2-Butanone can be heated with hydrochloric acid or sodium hydroxide to react a condensation reactions to generate 3,4-dimethyl-3-hexen-2-one or 3-methyl-3-hepten-5-one. If exposed long time under sunshine, 2-Butanone will convert into ethane, acetic acid or condensation compound. In addition, 2-Butanone can be oxidized into biacetyl by nitric acid. It can also react with phenol to give 2,2-di(4-hydroxyphenyl)butane.

Preparation: 2-Butanone is biosynthesized by some trees and found in some fruits and vegetables in small amounts. 2-Butanone can also be produced by oxidation or dehydrogenation of 2-Butanol using a catalyst based on copper, zinc, or bronze:

CH₃CH(OH)CH₂CH₃ + O₂ → CH₃C(O)CH₂CH₃
CH₃CH(OH)CH₂CH₃ → CH₃C(O)CH₂CH₃ + H₂

Moreover, 2-Butanone is made by the sulfation and hydration of 1 or 2-butgne to sec-butyl alcohol, which is then dehydrogenated to the ketone.

CH₃CH₂CH=CH₂ → CH₃CH₂CH(OH)CH₃
CH₃CH=CHCH₃ → CH₃CH₂CH(OH)CH₃
CH₃CH₂CH(OH)CH₃ → CH₃CH₂C(=O)CH₃

Uses: 2-Butanone is commonly used as an industrial solvent in processes involving gums, resins, cellulose acetate and nitrocellulose coatings and in vinyl films. For this reason, 2-Butanone was found use in the manufacture of plastics, textiles, in the production of paraffin wax, and in household products such as lacquer, varnishes, paint remover, a denaturing agent for denatured alcohol, glues, and as a cleaning agent. Because 2-Butanone dissolves polystyrene, it is used as a welding agent used in connecting together parts of scale model kits. 2-Butanone is the precursor to produce methyl ethyl ketone peroxide which is a catalyst for some polymerization reactions.

When you are using 2-Butanone, you should be cautious about it. The substance is highly flammable and irritant, which is irritating to eyes. If repeated exposure, 2-Butanone may cause skin dryness or cracking. Its vapours may cause drowsiness and dizziness. In addition, you should keep its container in a well-ventilated place and keep 2-Butanone away from sources of ignition - No smoking.

Descriptors computed from structure of 2-Butanone:
(1)Canonical SMILES: CCC(=O)C
(2)InChI: InChI=1S/C4H8O/c1-3-4(2)5/h3H2,1-2H3
(3)InChIKey: ZWEHNKRNPOVVGH-UHFFFAOYSA-N

Toxicity of 2-Butanone: