isobutyric acid isobutyric acid isobutyric acid, also known as 2-methylpropanoic acid or isobutanoic acid, is a carboxylic acid with structural formula (ch3)2chcooh. it is an isomer of n-butyric acid. it is classified as a short-chain fatty acid. deprotonation or esterification gives derivatives called isobutyrates. "valerianic acid" redirects here. not to be confused with valerenic acid or valeric acid. isobutyric acid names preferred iupac name 2-methylpropanoic acid other names isobutyric acid2-methylpropionic acidisobutanoic acid identifiers cas number 79-31-2 y 3d model (jsmol) interactive image 3dmet b00469 chebi chebi:16135 y chembl chembl108778 y chemspider 6341 y drugbank db02531 y echa infocard 100.001.087 ec number 201-195-7 iuphar/bps 1060 kegg c02632 y pubchem cid 6590 rtecs number nq4375000 unii 8ll210o1u0 y un number 2529 comptox dashboard (epa) dtxsid4021636 inchi inchi=1s/c4h8o2/c1-3(2)4(5)6/h3h,1-2h3,(h,5,6) ykey: kqnpfqtwmsnsap-uhfffaoysa-n yinchi=1/c4h8o2/c1-3(2)4(5)6/h3h,1-2h3,(h,5,6)key: kqnpfqtwmsnsap-uhfffaoyab smiles o=c(o)c(c)c properties chemical formula c4h8o2 molar mass 88.11 g/mol density 0.9697 g/cm3 (0 °c) melting point −47 °c (−53 °f; 226 k) boiling point 155 °c (311 °f; 428 k) acidity (pka) 4.86 magnetic susceptibility (χ) -56.06x10−6 cm3/mol hazards ghs labelling: pictograms signal word danger hazard statements h226, h302, h311, h314 p210 - p280 - p301 + p312 + p330 - p303 + p361 + p353 - p305 + p351 + p338 + p310 precautionary statements p210, p280, p301+p312+p330, p303+p361+p353, p305+p351+p338+p310 nfpa 704 (fire diamond) 3 2 0 flash point 55 °c (131 °f; 328 k) except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references isobutyric acid is a colorless liquid with a somewhat unpleasant odor. it is soluble in water and organic solvents. it is found naturally in carobs (ceratonia siliqua), in vanilla, and in the root of arnica dulcis, and as an ethyl ester in croton oil. production isobutyric acid is manufactured by the oxidation of isobutyraldehyde, which is a byproduct of the hydroformylation of propylene. it can also be prepared by the high pressure hydrocarboxylation (koch reaction) from propylene: ch3ch=ch2 + co + h2o → (ch3)2chco2h isobutyric acid can also be manufactured commercially using engineered bacteria with a sugar feedstock. laboratory methods many routes are known including the hydrolysis of isobutyronitrile with alkalis and the oxidation of isobutanol with potassium dichromate in the presence of sulfuric acid. in the presence of proton donors, the action of sodium amalgam on methacrylic acid also gives isobutyric acid. reactions the acid reacts as a typical carboxylic acid: it can form amide, ester, anhydride, and chloride derivatives. its acid chloride is commonly used as the intermediate to obtain the others. when heated with a chromic acid solution it is oxidized to acetone. alkaline potassium permanganate oxidizes it to α-hydroxyisobutyric acid, (ch3)2c(oh)-co2h. uses isobutyric acid and its volatile esters are present naturally in a wide variety of foods and, at varying concentrations, can impart a range of flavors. the compound's safety as a food additive was reviewed by an fao and who panel, who concluded that there were no concerns at the likely levels of intake. biology in humans, isobutyric acid is a minor product of the gut microbiome and can also be produced by metabolism of its esters found in food. it has a characteristic odor like rancid butter (4-carbon organic compounds take the root, butyl, which is in turn from butyric which is in turn from the latin word for butter and the greek, βούτυρον) but anosmia for it has been reported in about 2.5% of people. the metabolism of isobutyric acid in plants has been studied. isobutyric acid, along with several other short-chain fatty acids collectively known as "copulins," is found abundantly in human vaginal secretions. levels of isobutyric acid fluctuate throughout the menstrual cycle, and it is hypothesized to act as an indicator of ovulatory status. similar cycles are observed in chimpanzees.