Cyclopentanone

Chemical properties

Cyclopentanone is a colorless liquid with a pleasant, slightly pepperminty odor. It is soluble in water and miscible with common organic solvents. Cyclopentanone has an agreeable, peppermint-like odor. It tends to polymerize in the presence of acids.

Occurrence

Reported found in roasted onion, baked potato, tomato, gruyere cheese, butter, heated chicken, boiled beef, heated pork, roasted pecan, yellow passion fruit juice.

The Uses of Cyclopentanone

Cyclopentanone is used as an intermediate in the synthesis of rubber adhesives, synthetic resins, pharmaceuticals and biologically active compounds. It acts as precursor for the preparation of cyclopentamine and also pentethylcyclanone, cyclopentobarbital. It is a useful laboratory reagent and is used as thinner for epoxies. It can also be used as a solvent in paint and varnish removers and for electronic applications. As a dry cleaning agent, it is used for oil extraction. It is also involved in the preparation of cyclopentanone derivatives like cyclopenylamine and cyclopentanol which find application in the perfume industry.

Definition

ChEBI: A cyclic ketone that consists of cyclopentane bearing a single oxo substituent.

Preparation

Prepared by heating adipic acid (285 to 295°C) in the presence of barium hydroxide, distilling, ether extraction and then fractionation.

Aroma threshold values

Aroma characteristics at 2.0%: musty, slightly toasted bitter almondlike nutty, solventlike with a powdery nuance.

Taste threshold values

Taste characteristics at 20 ppm: musty, toasted nutty with a slight meaty nuance.

General Description

A clear colorless liquid with a petroleum-like odor. Flash point 87°F. Less dense than water and insoluble in water. Vapors heavier than air.

Air & Water Reactions

Highly flammable. Insoluble in water.

Reactivity Profile

Cyclopentanone polymerizes easily, especially in the presence of acids. Can react with oxidizing materials, i.e. hydrogen peroxide.

Health Hazard

Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.

Safety Profile

Moderately toxic by intraperitoneal and subcutaneous routes. A skin and severe eye irritant. Dangerous fire hazard when exposed to heat or flame; can react with oxidizers. To fight fire, use alcohol foam, foam, CO2, dry chemical. Potentially explosive reaction with hydrogen peroxide + nitric acid. When heated to decomposition it emits acrid smoke and fumes. See also KETONES.

Purification Methods

Shake it with aqueous KMnO4 to remove materials absorbing around 230 to 240nm. Dry it with Linde-type 13X molecular sieves and fractionally distil it. It has also been purified by conversion to the NaHSO3 adduct which, after crystallising four times from EtOH/water (4:1), is decomposed by adding to an equal weight of Na2CO3 in hot H2O. The free cyclopentanone is steam distilled from the solution. The distillate is saturated with NaCl and extracted with *benzene which is then dried (anhydrous K2CO3) and evaporated. The residue is then distilled [Allen, et al. J Chem Soc 1909 1960]. [Beilstein 7 IV 5.]