Names | |
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IUPAC name N-Benzoylglycine | |
Preferred IUPAC name Benzamidoacetic acid | |
Other names
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Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.007.098 |
KEGG | |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C9H9NO3 | |
Molar mass | 179.175 g·mol−1 |
Density | 1.371 g/cm3 |
Melting point | 187 to 188 °C (369 to 370 °F; 460 to 461 K) |
Boiling point | 240 °C (464 °F; 513 K) (decomposes) |
Hazards | |
Safety data sheet (SDS) | Material Safety Data Sheet |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Hippuric acid (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 consumption of phenolic compounds (such as in fruit juice, tea and wine). The phenols are first converted to benzoic acid, and then to hippuric acid and excreted in urine. [1]
Hippuric acid crystallizes in rhombic prisms which are readily soluble in hot water, melt at 187 °C, and decompose at about 240 °C. [2] High concentrations of hippuric acid may also indicate a toluene intoxication; however, scientists have called this correlation into question because there are other variables that affect levels of hippuric acid. [3] When many aromatic compounds such as benzoic acid and toluene are taken internally, they are converted to hippuric acid by reaction with the amino acid, glycine.
A modern synthesis of hippuric acid involves the acylation of glycine with benzoyl chloride ("Schotten–Baumann reaction"). [4]
Biochemically, hippuric acid is produced from benzoic acid and glycine, which occurs in the liver, intestine, and kidneys. [5] In terms of mechanism, benzoic acid is converted to benzoyl CoA, an acylating agent. [6]
Hippuric acid may be formed from the essential amino acid phenylalanine through at least two pathways. Phenylalanine undergoes biotransformation to form an alpha-keto acid, phenylpyruvic acid, which can tautomerize to a reactive enol. The benzylic carbon is reactive which undergoes peroxidation followed by the competing pathways to either react with the alpha carbon subsequently form an dioxetanol intermediate followed by formation of oxalic acid and benzaldehyde, or, peroxidation can react with the carboxyl group to form an alpha-keto-beta-peroxylactone intermediate followed by formation of carbon monoxide, carbon dioxide, and benzaldehyde. Alternatively, under certain conditions, phenylpyruvic acid may undergo a redox mechanism, such as Iron(II) donating an electron, to directly release carbon dioxide, followed by carbon monoxide, for the formation of a stable toluene radical which is resolved by an antioxidant such as ascorbate. In all of the aforementioned cases, benzaldehyde undergoes biotransformation via CYP450 to benzoic acid followed by conjugation to glycine for formation of hippurate which undergoes urinary excretion. [7] Similarly, toluene reacts with CYP450 to form benzaldehyde. [8]
Hippuric acid has been reported to be a marker for Parkinson's disease. [9]
Hippuric acid is readily hydrolysed by hot caustic alkalis to benzoic acid and glycine. Nitrous acid converts it into benzoyl glycolic acid, C6H5C(=O)OCH2CO2H.[ citation needed ] Its ethyl ester reacts with hydrazine to form hippuryl hydrazine, C6H5CONHCH2CONHNH2, which was used by Theodor Curtius for the preparation of hydrazoic acid. [2]
Justus von Liebig showed in 1829 that hippuric acid differed from benzoic acid and he named it, [10] and in 1834 he determined its constitution, [11] while in 1853 French chemist Victor Dessaignes (1800–1885) synthesized it by the action of benzoyl chloride on the zinc salt of glycine. [12] It was also formed by heating benzoic anhydride with glycine, [13] and by heating benzamide with monochloroacetic acid. [2]
Benzoic acid is a white solid organic compound with the formula C6H5COOH, whose structure consists of a benzene ring with a carboxyl substituent. The benzoyl group is often abbreviated "Bz", thus benzoic acid is also denoted as BzOH, since the benzoyl group has the formula –C6H5CO. It is the simplest aromatic carboxylic acid. The name is derived from gum benzoin, which was for a long time its only source.
Benzonitrile is the chemical compound with the formula C6H5(CN), abbreviated PhCN. This aromatic organic compound is a colorless liquid with a sweet bitter almond odour. It is mainly used as a precursor to the resin benzoguanamine.
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 alcohol is a colorless liquid with a mild pleasant aromatic odor. It is useful as a solvent for its polarity, low toxicity, and low vapor pressure. Benzyl alcohol has moderate solubility in water (4 g/100 mL) and is miscible in alcohols and diethyl ether. The anion produced by deprotonation of the alcohol group is known as benzylate or benzyloxide.
Styphnic acid, or 2,4,6-trinitro-1,3-benzenediol, is a yellow astringent acid that forms hexagonal crystals. It is used in the manufacture of dyes, pigments, inks, medicines, and explosives such as lead styphnate. It is itself a low-sensitivity explosive, similar to picric acid, but explodes upon rapid heating.
Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula C7H5ClO. It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring with an acyl chloride substituent. It is mainly useful for the production of peroxides but is generally useful in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins.
The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction which involves the base-induced disproportionation of two molecules of a non-enolizable aldehyde to give a primary alcohol and a carboxylic acid.
The benzoin addition is an addition reaction involving two aldehydes. The reaction generally occurs between aromatic aldehydes or glyoxals, and results in formation of an acyloin. In the classic example, benzaldehyde is converted to benzoin.
Glycolic acid 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 is a salt or ester of glycolic acid.
Wilhelm Rudolph Fittig was a German chemist. He discovered the pinacol coupling reaction, mesitylene, diacetyl and biphenyl. Fittig studied the action of sodium on ketones and hydrocarbons. He discovered the Fittig reaction or Wurtz–Fittig reaction for the synthesis of alkylbenzenes, he proposed a diketone structure for benzoquinone and isolated phenanthrene from coal tar. He discovered and synthesized the first lactones and investigated structures of piperine, naphthalene, and fluorene.
Toluene toxicity refers to the harmful effects caused by toluene on the body.
The Erlenmeyer–Plöchl azlactone and amino acid synthesis, named after Friedrich Gustav Carl Emil Erlenmeyer who partly discovered the reaction, is a series of chemical reactions which transform an N-acyl glycine to various other amino acids via an oxazolone.
Adolph Strecker was a German chemist who is remembered primarily for his work with amino acids.
Mellitic anhydride, the anhydride of mellitic acid, is an organic compound with the formula C12O9.
Benzene is an organic chemical compound with the molecular formula C6H6. The benzene molecule is composed of six carbon atoms joined in a planar hexagonal ring with one hydrogen atom attached to each. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.
In chemistry, the haloform reaction is a chemical reaction in which a haloform is produced by the exhaustive halogenation of an acetyl group, in the presence of a base. The reaction can be used to transform acetyl groups into carboxyl groups or to produce chloroform, bromoform, or iodoform. Note that fluoroform can't be prepared in this way.
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.
Conhydrine is a poisonous alkaloid found in poison hemlock in small quantities.
Radical theory is an obsolete scientific theory in chemistry describing the structure of organic compounds. The theory was pioneered by Justus von Liebig, Friedrich Wöhler and Auguste Laurent around 1830 and is not related to the modern understanding of free radicals. In this theory, organic compounds were thought to exist as combinations of radicals that could be exchanged in chemical reactions just as chemical elements could be interchanged in inorganic compounds.
Cyameluric acid or 2,5,8-trihydroxy-s-heptazine is a chemical compound with formula C
6N
7O
3H
3, usually described as a heptazine molecule with the hydrogen atoms replaced by hydroxyl groups –OH; or any of its tautomers.
Victor Dessaignes was a French lawyer, physician and chemist. Dessaignes conducted experiments on organic acids and was involved in the synthesis of hippuric acid. He was also involved in characterizing and naming malonic acid, the synthesis of asparagine from ammonium dimalate, conversion between optical isomers of tartaric acid, fumaric acid in mushrooms and the synthesis of several amides.