Benzilic acid is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The ...

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

aromatic In chemistry, aromaticity is a chemical property of cyclic ( ring-shaped), ''typically'' planar (flat) molecular structures with pi bonds in resonance (those containing delocalized electrons) that gives increased stability compared to satur ...

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 a heating 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 photoinitia ...

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an Alcohol (chemistry), alcohol with the chemical formula . Its formula can be also written as or (an ethyl ...

, 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 exp ...

. Another preparation, performed by

Liebig Justus Freiherr von Liebig (12 May 1803 – 20 April 1873) was a German scientist who made major contributions to agricultural and biological chemistry, and is considered one of the principal founders of organic chemistry. As a professor at the ...

in 1838, is the

dimerization A dimer () (''wikt:di-, di-'', "two" + ''-mer'', "parts") is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, Covalent bond, covalent or Intermolecular force, intermolecular. Dimers also have significant im ...

benzaldehyde 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. ...

, 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. Firs ...

reaction.

Uses

Benzilic acid is used in the manufacture of

glycollate Glycolic acid (or hydroxyacetic acid; chemical formula HOCH2CO2H) is a colorless, odorless and hygroscopic crystalline solid, highly soluble in water. It is used in various skin-care products. Glycolic acid is widespread in nature. A glycolate (so ...

pharmaceuticals including

clidinium Clidinium bromide (INN) is an anticholinergic (specifically a muscarinic antagonist) drug. It may help symptoms of cramping and abdominal/stomach pain by decreasing stomach acid, and slowing the intestines. It is commonly prescribed in combinati ...

dilantin Phenytoin (PHT), sold under the brand name Dilantin among others, is an 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 seizures. The intr ...

, flutropium, and

mepenzolate Mepenzolate is an antimuscarinic A muscarinic receptor antagonist (MRA) is a type of anticholinergic agent that blocks the activity of the muscarinic acetylcholine receptor. The muscarinic receptor is a protein involved in the transmission of s ...

which are

antagonists An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

of the

muscarinic acetylcholine receptor Muscarinic acetylcholine receptors, or mAChRs, are acetylcholine receptors that form G protein-coupled receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-rece ...

s. It is used in manufacture of the

incapacitating agent The term incapacitating agent is defined by the United States Department of Defense as: :"An agent that produces temporary physiological or mental effects, or both, which will render individuals incapable of concerted effort in the performance o ...

3-quinuclidinyl benzilate 3-Quinuclidinyl benzilate (QNB) (IUPAC name 1-azabicyclo .2.2ctan-3-yl hydroxy(diphenyl)acetate; US Army code EA-2277; NATO code BZ; Soviet code Substance 78) is an odorless and bitter-tasting military incapacitating agent.QNB: Incapacitating Age ...

(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 are a large, diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mood, and perception as well as other changes. Most hallucinogens can be categorized ...

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

References

{{Reflist

External links

Solubility in alcoholsConverting Benzaldehyde to Benzilic Acid
Benzhydryl compounds Acetic acids