In
organic chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, ...
, the Claisen–Schmidt condensation is the reaction between an
aldehyde
In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...
or
ketone having an α-hydrogen with an aromatic carbonyl compound lacking an
α-hydrogen
In the nomenclature of organic chemistry, a locant is a term to indicate the position of a functional group or substituent within a molecule.
Numeric locants
The International Union of Pure and Applied Chemistry (IUPAC) recommends the use of ...
. This reaction is named after two of its pioneering investigators
Rainer Ludwig Claisen
Rainer Ludwig Claisen (; 14 January 1851 – 5 January 1930) was a German chemist best known for his work with condensations of carbonyls and sigmatropic rearrangements. He was born in Cologne as the son of a jurist and studied chemistry at the u ...
and
J. G. Schmidt, who independently published on this topic in 1880 and 1881. An example is the synthesis of
dibenzylideneacetone
Dibenzylideneacetone or dibenzalacetone, often abbreviated dba, is an organic compound with the formula C17H14O. It is a pale-yellow solid insoluble in water, but soluble in ethanol.
It was first prepared in 1881 by the German chemist Rainer Ludwi ...
((1''E'', 4''E'')-1,5-diphenylpenta-1,4-dien-3-one).
:
Quantitative yields in Claisen–Schmidt reactions have been reported in the absence of solvent using
sodium hydroxide as the
base and plus
benzaldehydes
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.
It is a colorless liquid with a characteristic almond-like odor ...
.
[{{cite journal , doi = 10.3390/molecules17010571 , volume=17 , title=A Facile Solvent Free Claisen-Schmidt Reaction: Synthesis of α,α′-bis-(Substituted-benzylidene)cycloalkanones and α,α′-bis-(Substituted-alkylidene)cycloalkanones , year=2012 , journal=Molecules , pages=571–583 , author=Rahman A. F. M. Motiur, Ali Roushown, Jahng Yurngdong, Kadi Adnan A., pmid=22231494 , doi-access=free ] Because the enolizeable nucleophilic carbonyl compound and the electrophilic carbonyl compound are two different chemicals, the Claisen–Schmidt reaction is an example of a crossed aldol process.
References
Condensation reactions
Carbon-carbon bond forming reactions