Benzilic acid is an

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with formula or ()₂(HO)C(COOH). It is a white crystalline

aromatic In organic chemistry, aromaticity is a chemical property describing the way in which a conjugated system, conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibits a stabilization stronger than would be expected from conjugati ...

acid, soluble in many

primary alcohol A primary alcohol is an alcohol in which the hydroxy group is bonded to a primary carbon atom. It can also be defined as a molecule containing a “–CH2OH” group. In contrast, a secondary alcohol has a formula “–CHROH” and a tertiary ...

Preparation

Benzilic acid can be prepared by heating a mixture of

benzil Benzil (i.e. Bz2, systematically known as 1,2-diphenylethane-1,2-dione) is the organic compound with the formula ( C6H5 CO)2, generally abbreviated ( PhCO)2. This yellow solid is one of the most common diketones. Its main use is as a photoinitiat ...

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

, and

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

. Another preparation, performed by

Liebig Justus ''Freiherr'' von Liebig (12 May 1803 – 18 April 1873) was a Germans, German scientist who made major contributions to the theory, practice, and pedagogy of chemistry, as well as to agricultural and biology, biological chemistry; he is ...

in 1838, is the

dimerization In chemistry, dimerization is the process of joining two identical or similar molecular entities by bonds. The resulting bonds can be either strong or weak. Many symmetrical chemical species are described as dimers, even when the monomer is u ...

benzaldehyde Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is among the simplest aromatic aldehydes and one of the most industrially useful. It is a colorless liquid with a characteristic almond-li ...

, to

, which is transformed to the product by the

benzilic acid rearrangement The benzilic acid rearrangement is formally the 1,2-rearrangement of 1,2- diketones to form α- hydroxy–carboxylic acids using a base. This reaction receives its name from the reaction of benzil with potassium hydroxide to form benzilic acid. ...

reaction.

Uses

Benzilic acid is used in the manufacture of glycollate pharmaceuticals including clidinium,

dilantin Phenytoin (PHT), sold under the brand name Dilantin among others, is an anticonvulsant, anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence se ...

, flutropium, and

mepenzolate Mepenzolate is an antimuscarinic A muscarinic acetylcholine receptor antagonist, also simply known as a muscarinic antagonist or as an antimuscarinic agent, is a type of anticholinergic drug that blocks the activity of the muscarinic acetylchol ...

which are

antagonists An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.muscarinic acetylcholine receptor Muscarinic acetylcholine receptors (mAChRs) are acetylcholine receptors that form G protein-coupled receptor, G protein-coupled receptor complexes in the cell membranes of certain neurons and other Cell (biology), cells. They play several role ...

s. It is used in manufacture of the

incapacitating agent Incapacitating agent is a chemical or biological agent which renders a person unable to harm themselves or others, regardless of consciousness. Lethal agents are primarily intended to kill, but incapacitating agents can also kill if administered ...

3-quinuclidinyl benzilate (BZ) which is regulated by the

Chemical Weapons Convention The Chemical Weapons Convention (CWC), officially the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, is an arms control treaty administered by the Organisation for ...

. It is also monitored by law enforcement agencies of many countries, because of its use in the manufacture in

hallucinogenic drug Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, moo ...

s.Nerve Agent Precursors: Benzilic acid and Methyl Benzilate
, Factsheets on Chemical and Biological Warfare Agents, Chemical precursors. Benzilic acid can be reduced with

hydroiodic acid Hydroiodic acid (or hydriodic acid) is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula . It is a strong acid, in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous ...

to give diphenylacetic acid 17-34-0Systematic organic chemistry, by W. M. Cumming, 192-193, 1937

References

{{Reflist

External links

Solubility in alcoholsConverting Benzaldehyde to Benzilic Acid
Benzhydryl compounds Phenylacetic acids