Benzoyl chloride
- Benzoic acid
- Benzocarbonylchlorid
- BzCl
Colorless, fuming in moist air, lachrymatory liquid with a pungent odor
Liquid
1.22 g · cm -3
-1 ° C
197 ° C
50 Pa ( 20 ° C)
Decomposition in water
1.5537 (20 ° C)
Risk
Not determined, as evidence of a carcinogenic effect
Template: Infobox chemical / molecular formula search available
Benzoyl chloride is a colorless, moist air due to the decomposition to hydrochloric acid and benzoic acid, slightly fuming liquid chemical. Formally, it is the chloride of benzoic acid. The unpleasant and pungent smelling vapors irritate the respiratory tract and eyes.
Production and representation
Benzoyl chloride can be prepared by the reaction of benzoic acid with thionyl chloride ( or with phosphorus (III ) chloride and phosphorus (V ) chloride, or phosgene).
However, most important methods of industrial production of the benzoyl chloride are the chlorination of benzaldehyde:
As well as the controlled hydrolysis of benzotrichloride:
Or its reaction with benzoic acid:
Properties
Benzoyl chloride is a slightly flammable liquid (flash-point between 55 and 100 ° C), may form an explosive mixture with air their vapors when heated above its flash point of the substance. Benzoyl chloride reacts with water in a hydrolysis reaction to benzoic acid and hydrochloric acid.
Reaction with ammonia, benzamide can be produced.
Use
Benzoyl chloride is used, inter alia, for the preparation of benzoic acid esters. Because of its low solubility in water, the esterification can be performed well by the Schotten- Baumann method. The use of carboxylic acid chlorides, instead of the carboxylic acid provides significantly higher yields.
In Nucleinsäurenchemie benzoyl chloride in pyridine as solvent is used as a popular reagent for introduction of the benzoyl protective group to protect secondary alcohols. The protecting group can be easily removed by alkaline hydrolysis of the benzoic again.
Safety
Upon contact with water (eg, from the air), hazardous hydrogen chloride vapors. Any skin contact should be avoided, benzoyl chloride causes painful burns. Should be avoided inhaling the fumes. In animal experiments proved benzoyl chloride (probably because of the extremely rapid metabolism to benzoic acid, hippuric acid and hydrogen chloride ) is not considered to be genotoxic. Statements carcinogenicity can not be taken at the time.