Cyclohexanone

• Pimelinketon
• Anon

Colorless liquid with an odor pfefferminzartigem

Liquid

0.95 g · cm -3 ( 20 ° C)

-26 ° C

156 ° C.

5 hPa (20 ° C)

• 9.7 % by mass in water ( 19.5 ° C)
• Soluble in ethanol and diethyl ether

1.4507 (20 ° C)

Attention

Repealed as evidence of a carcinogenic effect

Template: Infobox chemical / molecular formula search available

Cyclohexanone is a colorless, water-clear liquid whose odor reminiscent of acetone in the pure state. It belongs to the group of cyclic ketones.

• 7.1 Material Safety Data Sheets
• 7.2 Operating Instructions

Production and representation

For the industrial synthesis of cyclohexanone mainly two methods are available:

1), the catalytic oxidation of cyclohexane with oxygen passing through the unstable cyclohexyl and a free-radical mechanism follows. A mixture of cyclohexanone and cyclohexanol is formed, which is also abbreviated as Anon and Anol. The mixture can be separated by distillation.

2) The oxidation of cyclohexanol with nitric acid, or diluted in the gas phase of zinc oxide catalysts. Cyclohexanol is previously prepared by the hydrogenation of phenol to a nickel catalyst:

On a laboratory scale cyclohexanone can salts by oxidation of cyclohexanol in acid solution with chromium ( VI), are, for example, sodium dichromate obtained. This reaction is mechanistically a chromic acid ester of cyclohexanol:

The enzymatic double oxidation of cyclohexane to cyclohexanone is also described in the literature.

Properties

Physical Properties

Cyclohexanone is a colorless liquid with a density of 0.947 g/cm3 at room temperature. It solidifies at -31 ° C and boiling at atmospheric pressure at 155 ° C. It is miscible with most common organic solvents at any ratio. The miscibility with water is limited. The solubilities be at 20 ° C. 9.0 g of cyclohexanone in 100 g of water and 5.7 g of water in 100 g of cyclohexanone. These solubilities are temperature dependent. With increasing temperature the solubility of cyclohexanone in water decreases and increases the solubility of water in cyclohexanone. With water a constant boiling ( azeotropic ) mixture exists at 96 ° C and 57 % water content.

Chemical Properties

Cyclohexanone shows the typical ketones reactions, for example:

• Imine formation with ammonia and primary amines,
• Enamine with secondary amines (see below),
• CH- acidity of the CH2 groups of the carbonyl group adjacent to and associated Enolisierbarkeit,
• Aldol reactions under base or acid catalysis,
• Reaction with Grignard reagents,

Etc.

With sodium borohydride, it can be easily reduced to cyclohexanol. Of concentrated nitric acid ( 65 % strength), it is oxidized at 30-40 ° C under ring opening to give adipic acid. For the synthesis of adipic acid from cyclohexanol one assumes, however, the initially formed after the reaction above cyclohexanone further reacts immediately.

Safety characteristics

Cyclohexanone forms inflammatory vapor -air mixtures. The compound has a flash point of 43 ° C. The explosion range is between 1.3 vol % (53 g/m3) as the lower explosive limit ( LEL) and 9.4 % by volume (380 g/m3 ) and upper explosive limit (UEL The MESG was determined to be 0.95 mm., It results so that an assignment to the explosion group IIA. the ignition temperature is 430 ° C. the substance falls within the temperature class T2.

Use

The most important industrial use of cyclohexanone to ε -caprolactam implementation, which is used for the production of Perlon. First, ( used in the form of hydroxylamine hydrochloride ) by condensation with hydroxylamine cyclohexanone oxime formed, which is converted to a Beckmann rearrangement to ε -caprolactam:

Especially in practical experiments in chemical education, it serves as a typical representative of the cyclic ketones. For example, succeed in the formation of enamines or the α - alkylation with cyclohexanone as the starting material very well:

Because of its many possible responses as a ketone, it is often used in synthetic organic chemistry, when six-membered ring structure elements to be incorporated into scaffolds.

Furthermore, cyclohexanone is a very good solvent for coating raw materials, polyvinyl chloride, basic dyes and natural and synthetic resins. Also in opaque colors for leather, printing ink and paint strippers of the substance is present.

Safety

Cyclohexanone is particularly harmful if inhaled and may cause dizziness and headache. It forms when heated flammable vapors. Therefore, it should be handled under a fume hood. Protective gloves and goggles must be worn.

• If skin or eye contact should be immediately washed or rinsed with plenty of water. Consult a physician!
• If swallowed, drink plenty of water. Do not induce vomiting.
• Appropriate disposal as a non- halogenated solvent waste.