Benzoic acid () is a white (or colorless) solid

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 the formula , whose

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

consists of a

benzene Benzene is an Organic compound, organic chemical compound with the Chemical formula#Molecular formula, molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal Ring (chemistry), ring with one hyd ...

ring () with a

carboxyl In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl group (e.g. ...

()

substituent In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. The suffix ''-yl'' is used when naming organic compounds that contain a single bond r ...

. The benzoyl group is often abbreviated "Bz" (not to be confused with "Bn," which is used for

benzyl In organic chemistry, benzyl is the substituent or molecular fragment possessing the structure . Benzyl features a benzene ring () attached to a methylene group (). Nomenclature In IUPAC nomenclature, the prefix benzyl refers to a substituent ...

), thus benzoic acid is also denoted as BzOH, since the benzoyl group has the formula –. It is the simplest

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 ...

carboxylic acid. The name is derived from gum benzoin, which was for a long time its only source. Benzoic acid occurs naturally in many plants and serves as an intermediate in the biosynthesis of many

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

Salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

of benzoic acid are used as food preservatives. Benzoic acid is an important precursor for the industrial synthesis of many other organic substances. The salts and

ester In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...

s of benzoic acid are known as benzoates ().

History

Benzoic acid was discovered in the sixteenth century. The

dry distillation Dry distillation is the heating of solid materials to produce gaseous products (which may condense into liquids or solids). The method may involve pyrolysis or thermolysis, or it may not (for instance, a simple mixture of ice and glass could be ...

of gum benzoin was first described by

Nostradamus Michel de Nostredame (December 1503 – July 1566), usually Latinisation of names, Latinised as Nostradamus, was a French Astrology, astrologer, apothecary, physician, and reputed Oracle, seer, who is best known for his book ''Les Prophéti ...

(1556), and then by Alexius Pedemontanus (1560) and Blaise de Vigenère (1596).

Justus von 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 ...

and

Friedrich Wöhler Friedrich Wöhler Royal Society of London, FRS(For) HonFRSE (; 31 July 180023 September 1882) was a German chemist known for his work in both organic chemistry, organic and inorganic chemistry, being the first to isolate the chemical elements be ...

determined the composition of benzoic acid. These latter also investigated how

hippuric acid Hippuric acid (Greek language, Gr. ''hippos'', horse, ''ouron'', urine) is a carboxylic acid and organic compound. It is found in urine and is formed from the combination of benzoic acid and glycine. Levels of hippuric acid rise with the consumpt ...

is related to benzoic acid. In 1875 Salkowski discovered the

antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as ...

properties of benzoic acid, which explains the preservation of benzoate-containing cloudberry fruits.

Production

Industrial preparations

Benzoic acid is produced commercially by

partial oxidation Partial oxidation (POX) is a type of chemical reaction. It occurs when a substoichiometric fuel-air mixture is partially combusted in a reformer, creating a hydrogen-rich syngas which can then be put to further use, for example in a fuel cell. A d ...

toluene Toluene (), also known as toluol (), is a substituted aromatic hydrocarbon with the chemical formula , often abbreviated as , where Ph stands for the phenyl group. It is a colorless, water Water is an inorganic compound with the c ...

with

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

. The process is catalyzed by

cobalt Cobalt is a chemical element; it has Symbol (chemistry), symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. ...

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

naphthenates. The process uses abundant materials, and proceeds in high yield. : The first industrial process involved the reaction of

benzotrichloride Benzotrichloride (BTC), also known as α,α,α-trichlorotoluene, phenyl chloroform or (trichloromethyl)benzene, is an organic compound with the formula C6H5CCl3. Benzotrichloride is an unstable, colorless or somewhat yellowish, viscous, chlorinat ...

(trichloromethyl benzene) with

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed with water. Annually, approxim ...

in water, using

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

or iron salts as

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

. The resulting calcium benzoate is converted to benzoic acid with

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

. The product contains significant amounts of

chlorinated In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. ...

benzoic acid derivatives. For this reason, benzoic acid for human consumption was obtained by dry distillation of gum benzoin. Food-grade benzoic acid is now produced synthetically.

Laboratory synthesis

Benzoic acid is cheap and readily available, so the laboratory synthesis of benzoic acid is mainly practiced for its pedagogical value. It is a common undergraduate preparation. Benzoic acid can be purified by recrystallization from water because of its high solubility in hot water and poor solubility in cold water. The avoidance of organic solvents for the recrystallization makes this experiment particularly safe. This process usually gives a yield of around 65%.

By hydrolysis

Like other

nitrile In organic chemistry, a nitrile is any organic compound that has a functional group. The name of the compound is composed of a base, which includes the carbon of the , suffixed with "nitrile", so for example is called " propionitrile" (or pr ...

s and

amide In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a chemical compound, compound with the general formula , where R, R', and R″ represent any group, typically organyl functional group, groups or hydrogen at ...

benzonitrile Benzonitrile is the chemical compound with the formula , abbreviated PhCN. This aromatic organic compound is a colorless liquid with a cherry or almond like odour. It is mainly used industrially to produce the melamine resin precursor benzoguanam ...

and

benzamide Benzamide is an organic compound with the chemical formula of C7H7NO. It is the simplest amide derivative of benzoic acid. In powdered form, it appears as a white solid, while in crystalline form, it appears as colourless crystals. It is slightly ...

can be hydrolyzed to benzoic acid or its conjugate base in acid or basic conditions.

From Grignard reagent

Bromobenzene Bromobenzene is an aryl bromide and the simplest of the bromobenzenes, consisting of a benzene ring substituted with one bromine atom. Its chemical formula is . It is a colourless liquid although older samples can appear yellow. It is a reagent ...

can be converted to benzoic acid by "carboxylation" of the intermediate

phenylmagnesium bromide Phenylmagnesium bromide, with the simplified formula , is a magnesium-containing organometallic compound. It forms colorless crystals. It is commercially available as a solution in diethyl ether or tetrahydrofuran (THF). Phenylmagnesium bromide i ...

. This synthesis offers a convenient exercise for students to carry out a

Grignard reaction The Grignard reaction () is an organometallic chemical reaction in which, according to the classical definition, carbon alkyl, allyl, vinyl, or aryl magnesium halides (Grignard reagent) are added to the carbonyl groups of either an aldehyde or ...

, an important class of

carbon–carbon bond A carbon–carbon bond is a covalent bond between two carbon atoms. The most common form is the single bond: a bond composed of two electrons, one from each of the two atoms. The carbon–carbon single bond is a sigma bond and is formed between on ...

forming reaction in organic chemistry.

Oxidation of benzyl compounds

Benzyl alcohol Benzyl alcohol (also known as α-cresol) is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl a ...

and

benzyl chloride Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula . This colorless liquid is a reactive organochlorine compound that is a widely used chemical building block. Preparation Benzyl chloride is prepared industrially ...

and virtually all benzyl derivatives are readily oxidized to benzoic acid.

Uses

Benzoic acid is mainly consumed in the production of

phenol Phenol (also known as carbolic acid, phenolic acid, or benzenol) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile and can catch fire. The molecule consists of a phenyl group () ...

by oxidative decarboxylation at 300−400 °C:. : The temperature required can be lowered to 200 °C by the addition of catalytic amounts of copper(II) salts. The phenol can be converted to

cyclohexanol Cyclohexanol is the organic compound with the formula HOCH(CH2)5. The molecule is related to cyclohexane by replacement of one hydrogen atom by a hydroxyl group. This compound exists as a deliquescent colorless solid with a camphor-like odor, whi ...

, which is a starting material for

nylon Nylon is a family of synthetic polymers characterised by amide linkages, typically connecting aliphatic or Polyamide#Classification, semi-aromatic groups. Nylons are generally brownish in color and can possess a soft texture, with some varieti ...

synthesis.

Precursor to plasticizers

Benzoate

plasticizer A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizer ...

s, such as the glycol-, diethyleneglycol-, and triethyleneglycol esters, are obtained by

transesterification Transesterification is the process of exchanging the organic functional group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. Strong acids catalyze the r ...

of methyl benzoate with the corresponding

diol A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol may also be called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. They are used as protecting gro ...

. These plasticizers, which are used similarly to those derived from

terephthalic acid Terephthalic acid is an organic compound with formula C6H4(CO2H)2. This white solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tons are produced annuall ...

ester, represent alternatives to

phthalate Phthalates ( ), or phthalate esters, are esters of phthalic acid. They are mainly used as plasticizers, i.e., substances added to plastics to increase their flexibility, transparency, durability, and longevity. They are used primarily to soften ...

Precursor to sodium benzoate and related preservatives

Benzoic acid and its salts are used as food preservatives, represented by the E numbers E210, E211, E212, and E213. Benzoic acid inhibits the growth of

mold A mold () or mould () is one of the structures that certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal ...

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom (biology), kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are est ...

and some

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

. It is either added directly or created from reactions with its

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

, or

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

salt. The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH changes to 5 or lower, the anaerobic fermentation of

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

through phosphofructokinase is decreased by 95%. The efficacy of benzoic acid and benzoate is thus dependent on the pH of the food. Benzoic acid, benzoates and their derivatives are used as

preservative A preservative is a substance or a chemical that is added to products such as food products, beverages, pharmaceutical drugs, paints, biological samples, cosmetics, wood, and many other products to prevent decomposition by microbial growth or ...

s for acidic foods and beverages such as

citrus fruit ''Citrus'' is a genus of flowering plant, flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as Orange (fruit), oranges, Mandarin orange, mandarins, lemons, grapefruits, ...

juice Juice is a drink made from the extraction or Cold-pressed juice, pressing of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with concentrate or other biological food sources, such as meat ...

s (

citric acid Citric acid is an organic compound with the formula . It is a Transparency and translucency, colorless Weak acid, weak organic acid. It occurs naturally in Citrus, citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, ...

), sparkling drinks (

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

soft drinks A soft drink (see § Terminology for other names) is a class of non-alcoholic drink, usually (but not necessarily) carbonated, and typically including added sweetener. Flavors used to be natural, but now can also be artificial. The sweet ...

(

phosphoric acid Phosphoric acid (orthophosphoric acid, monophosphoric acid or phosphoric(V) acid) is a colorless, odorless phosphorus-containing solid, and inorganic compound with the chemical formula . It is commonly encountered as an 85% aqueous solution, ...

pickles Pickle, pickled or Pickles may refer to: Food * Pickle, a food that has undergone pickling * Pickled cucumber * Pickle, a sweet, vinegary pickled chutney popular in Britain, such as Branston Pickle, also known as "sweet pickle" or "ploughman's ...

(

vinegar Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

) and other acidified foods. Typical

concentrations In chemistry, concentration is the Abundance (chemistry), abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: ''mass concentration (chemistry), mass concentration'', ...

of benzoic acid as a preservative in food are between 0.05 and 0.1%. Foods in which benzoic acid may be used and maximum levels for its application are controlled by local food laws. Concern has been expressed that benzoic acid and its salts may react with

ascorbic acid Ascorbic acid is an organic compound with formula , originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent. Asco ...

(vitamin C) in some soft drinks, forming small quantities of carcinogenic

Medicinal

Benzoic acid is a constituent of Whitfield's ointment which is used for the treatment of fungal skin diseases such as

ringworm Dermatophytosis, also known as tinea and ringworm, is a mycosis, fungal infection of the skin (a dermatomycosis), that may affect skin, hair, and nails. Typically it results in a red, itchy, scaly, circular rash. Hair loss may occur in the a ...

and

athlete's foot Athlete's foot, known medically as ''tinea pedis'', is a common skin infection of the feet caused by a fungus. Signs and symptoms often include itching, scaling, cracking and redness. In rare cases the skin may blister. Athlete's foot fungus ...

. As the principal component of gum benzoin, benzoic acid is also a major ingredient in both

tincture of benzoin Tincture of benzoin is a pungent solution of benzoin resin in ethanol. A similar preparation called Friar's Balsam or Compound Benzoin Tincture contains, in addition, Cape aloes or Barbados aloes and storax resin. The U.S. Navy stated that Comp ...

and Friar's balsam. Such products have a long history of use as topical

antiseptic An antiseptic ( and ) is an antimicrobial substance or compound that is applied to living tissue to reduce the possibility of sepsis, infection, or putrefaction. Antiseptics are generally distinguished from ''antibiotics'' by the latter's abil ...

s and inhalant

decongestant A decongestant, or nasal decongestant, is a type of pharmaceutical drug that is used to relieve nasal congestion in the upper respiratory tract. The active ingredient in most decongestants is either pseudoephedrine or phenylephrine (the latter o ...

s. Benzoic acid was used as an expectorant,

analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...

, and

in the early 20th century.

Niche and laboratory uses

In teaching laboratories, benzoic acid is a common standard for calibrating a

bomb calorimeter A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanic ...

Biology and health effects

Benzoic acid occurs naturally as do its esters in many plant and animal species. Appreciable amounts are found in most berries (around 0.05%). Ripe fruits of several ''

Vaccinium ''Vaccinium'' is a common and widespread genus of shrubs or dwarf shrubs in the heath family (Ericaceae). The fruits of many species are eaten by humans and some are of commercial importance, including the cranberry, blueberry, bilberry (wh ...

'' species (e.g.,

cranberry Cranberries are a group of evergreen dwarf shrubs or trailing vines in the subgenus ''Oxycoccus'' of the genus ''Vaccinium''. Cranberries are low, creeping shrubs or vines up to long and in height; they have slender stems that are not th ...

, ''V. vitis macrocarpon'';

bilberry Bilberries () are Eurasian low-growing shrubs in the genus ''Vaccinium'' in the flowering plant family Ericaceae that bear edible, dark blue berries. They resemble but are distinct from North American blueberries. The species most often referre ...

, ''V. myrtillus'') contain as much as 0.03–0.13% free benzoic acid. Benzoic acid is also formed in

apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

s after infection with the fungus '' Nectria galligena''. Among animals, benzoic acid has been identified primarily in omnivorous or phytophageous species, e.g., in viscera and muscles of the

rock ptarmigan The rock ptarmigan (''Lagopus muta'') is a medium-sized game bird in the grouse family. It is known simply as the ptarmigan in Europe. It is the official bird for the Canadian territory of Nunavut, where it is known as the ''aqiggiq'' (ᐊᕿ� ...

(''Lagopus muta'') as well as in gland secretions of male

muskox The muskox (''Ovibos moschatus'') is a hoofed mammal of the family Bovidae. Native to the Arctic, it is noted for its thick coat and for the strong odor emitted by males during the seasonal rut, from which its name derives. This musky odor ha ...

en (''Ovibos moschatus'') or Asian bull elephants ('' Elephas maximus''). Gum benzoin contains up to 20% of benzoic acid and 40% benzoic acid esters. In terms of its

biosynthesis Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...

, benzoate is produced in plants from

cinnamic acid Cinnamic acid is an organic compound with the formula phenyl, C6H5-CH=CH-Carboxylic acid, COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxy ...

. A pathway has been identified from

via 4-hydroxybenzoate.

Reactions

Reactions of benzoic acid can occur at either the

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

or at the

carboxyl group In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl group (e.g. ...

Aromatic ring

Electrophilic aromatic substitution Electrophilic aromatic substitution (SEAr) is an organic reaction in which an atom that is attached to an aromatic ring, aromatic system (usually hydrogen) is replaced by an electrophile. Some of the most important electrophilic aromatic substitut ...

reaction will take place mainly in 3-position due to the electron-withdrawing carboxylic group; i.e. benzoic acid is ''meta'' directing.

Carboxyl group

Reactions typical for

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an Substituent, R-group. The general formula of a carboxylic acid is often written as or , sometimes as with R referring to an organyl ...

s apply also to benzoic acid. * Benzoate

s are the product of the acid catalysed reaction with

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

s. * Benzoic acid

s are usually prepared from

benzoyl chloride Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula . It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring () with an acyl chloride () substituent. It is ...

. * Dehydration to benzoic anhydride is induced with

acetic anhydride Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula, formula . Commonly abbreviated , it is one the simplest organic acid anhydride, anhydrides of a carboxylic acid and is widely used in the production of c ...

phosphorus pentoxide Phosphorus pentoxide is a chemical compound with molecular formula Phosphorus, P4Oxygen, O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desic ...

. * Highly reactive acid derivatives such as acid halides are easily obtained by mixing with

halogenation In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drug ...

agents like

phosphorus chlorides In chemistry, there are three series of binary phosphorus halides, containing phosphorus in the oxidation states +5, +3 and +2. All compounds have been described, in varying degrees of detail, although serious doubts have been cast on the existenc ...

thionyl chloride Thionyl chloride is an inorganic compound with the chemical formula . It is a moderately Volatility (chemistry), volatile, colourless liquid with an unpleasant acrid odour. Thionyl chloride is primarily used as a Halogenation, chlorinating reagen ...

. * Orthoesters can be obtained by the reaction of alcohols under acidic water free conditions with

. * Reduction to

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 ...

and

benzyl alcohol Benzyl alcohol (also known as α-cresol) is an aromatic alcohol with the formula C6H5CH2OH. The benzyl group is often abbreviated "Bn" (not to be confused with "Bz" which is used for benzoyl), thus benzyl alcohol is denoted as BnOH. Benzyl a ...

is possible using DIBAL-H, LiAlH₄ or

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula (sometimes written as ). It is a white crystalline solid, usually encountered as an aqueous basic solution. Sodi ...

. *

Decarboxylation Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is ...

to benzene may be effected by heating in

quinoline Quinoline is a heterocyclic aromatic organic compound with the chemical formula C9H7N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only sl ...

in the presence of copper salts. Hunsdiecker decarboxylation can be achieved by heating the silver salt. :

Safety and mammalian metabolism

It is excreted as

. Benzoic acid is metabolized by butyrate-CoA ligase into an intermediate product, benzoyl-CoA, Substrate/Product which is then metabolized by glycine ''N''-acyltransferase into hippuric acid. Substrate/Product Humans metabolize

which is also excreted as hippuric acid. For humans, the

World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...

International Programme on Chemical Safety The International Programme on Chemical Safety (IPCS) was formed in 1980 and is a collaboration between three United Nations bodies, the World Health Organization, the International Labour Organization and the United Nations Environment Programme, ...

(IPCS) suggests a provisional tolerable intake would be 5 mg/kg body weight per day.

Cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s have a significantly lower tolerance against benzoic acid and its

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

than

rat Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include '' Neotoma'' (pack rats), '' Bandicota'' (bandicoo ...

s and

mice A mouse (: mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus' ...

. Lethal dose for cats can be as low as 300 mg/kg body weight. The oral for rats is 3040 mg/kg, for mice it is 1940–2263 mg/kg. In

Taipei , nickname = The City of Azaleas , image_map = , map_caption = , pushpin_map = Taiwan#Asia#Pacific Ocean#Earth , coordinates = , subdivision_type = Country ...

, Taiwan, a city health survey in 2010 found that 30% of dried and pickled food products had benzoic acid.

References

External links

* *
ChemicalLand
{{DEFAULTSORT:Benzoic Acid Excipients Phenyl compounds E-number additives

History

Production

Industrial preparations

Laboratory synthesis

By hydrolysis

From Grignard reagent

Oxidation of benzyl compounds

Uses

Precursor to plasticizers

Precursor to sodium benzoate and related preservatives

Medicinal

Niche and laboratory uses

Biology and health effects

Reactions

Aromatic ring

Carboxyl group

Safety and mammalian metabolism

See also

References

External links