Editing Formic acid (section)

==Chemical reactions==

===Decomposition===
Formic acid readily decomposes by dehydration in the presence of concentrated [[sulfuric acid]] to form [[carbon monoxide]] and water:
:HCO<sub>2</sub>H → H<sub>2</sub>O + CO

Treatment of formic acid with sulfuric acid is a convenient laboratory source of CO.<ref name="koch">{{cite journal |doi=10.15227/orgsyn.044.0001 |title=1-Adamantanecarboxylic Acid |journal=Organic Syntheses |date=1964 |volume=44 |page=1|first1=H.|last1=Koch|first2=W.|last2=Haaf }}</ref><ref name="coleman">{{OrgSynth|title=''p''-Tolualdehyde|author=Coleman, G. H.|author2=Craig, David|volume=12|pages=80|year=1932|doi=10.15227/orgsyn.012.0080}}</ref>

In the presence of [[platinum]], it decomposes with a release of [[hydrogen]] and [[carbon dioxide]].
:HCO<sub>2</sub>H → H<sub>2</sub> + CO<sub>2</sub>
Soluble [[ruthenium]] catalysts are also effective for producing carbon monoxide-free hydrogen.<ref name="Fellay2008">{{cite journal |doi=10.1002/anie.200800320 |pmid=18393267 |title=A Viable Hydrogen-Storage System Based on Selective Formic Acid Decomposition with a Ruthenium Catalyst |journal=Angewandte Chemie International Edition |volume=47 |issue=21 |year=2008 |last1=Fellay |first1=Céline |last2=Dyson |first2=Paul J. |last3=Laurenczy |first3=Gábor |pages=3966–8}}</ref>

===Reactant===
Formic acid shares most of the chemical properties of other [[carboxylic acid]]s. Because of its high acidity, solutions in alcohols form esters spontaneously; in [[Fischer esterification]]s of formic acid, it self-catalyzes the reaction and no additional acid catalyst is needed.<ref>{{cite book |last1=Furniss |first1=Brian S. |last2=Hannaford |first2=Antony, J. |last3=Smith |first3=Peter W. G. |last4=Tatchell |first4=Austin S. |edition=5th |year=1989 |title=Vogel's Textbook of Practical Organic Chemistry |publisher=Longman Scientific & Technical |page=696, 701 |isbn=978-0582462366}}</ref> Formic acid shares some of the [[redox|reducing]] properties of [[aldehyde]]s, reducing solutions of metal oxides to their respective metal.<ref>{{Cite book|last1=Ozawa|first1=Naoto|last2=Okubo|first2=Tatsuo|last3=Matsuda|first3=Jun|last4=Sakai|first4=Tatsuo|title=2016 11th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT) |chapter=Observation and analysis of metal oxide reduction by formic acid for soldering |date=October 2016|chapter-url=https://ieeexplore.ieee.org/document/7799990|pages=148–151|doi=10.1109/IMPACT.2016.7799990|isbn=978-1-5090-4769-7|s2cid=32545113}}</ref>

Formic acid is a source for a [[formyl]] group for example in the [[formylation]] of [[N-Methylaniline|''N''-methylaniline]] to ''N''-methylformanilide in [[toluene]].<ref>{{OrgSynth | title = ''N''-Methylformanilide | collvol = 3 | collvolpages = 590 | year = 1955 | prep = cv3p0590 | authorlink=Louis Fieser |author=L. F. Fieser |author2=J. E. Jones}}</ref>

In [[organic synthesis|synthetic organic chemistry]], formic acid is often used as a source of [[hydride]] ion, as in the [[Eschweiler–Clarke reaction]]:
[[Image:Eschweiler-Clarke Reaction.svg|center|300px|The Eschweiler–Clark reaction]]

It is used as a source of hydrogen in [[transfer hydrogenation]], as in the [[Leuckart reaction]] to make [[amine]]s, and (in aqueous solution or in its [[azeotrope]] with [[triethylamine]]) for hydrogenation of [[ketone]]s.<ref name="Zhou2012">{{cite journal | last=Zhou | first=Xiaowei | display-authors=etal | title=Varying the ratio of formic acid to triethylamine impacts on asymmetric transfer hydrogenation of ketones | journal=Journal of Molecular Catalysis A: Chemical | volume=357 | year=2012 | issn=1381-1169 | doi=10.1016/j.molcata.2012.02.002 | pages=133–140}}</ref>

===Addition to alkenes===
Formic acid is unique among the carboxylic acids in its ability to participate in addition reactions with [[alkene]]s. Formic acids and alkenes readily react to form formate [[ester]]s. In the presence of certain acids, including [[sulfuric acid|sulfuric]] and [[hydrofluoric acid]]s, however, a variant of the [[Koch reaction]] occurs instead, and formic acid adds to the alkene to produce a larger carboxylic acid.<ref>{{cite journal |doi=10.1002/cber.19660990410 |title=Die Synthese sekundärer Carbonsäuren nach der Ameisensäure-Methode |journal=Chemische Berichte |volume=99 |issue=4 |pages=1149–52 |year=1966 |last1=Haaf |first1=Wolfgang }}</ref>

===Formic acid anhydride===
An unstable [[formic anhydride]], H(C=O)−O−(C=O)H, can be obtained by dehydration of formic acid with [[N,N'-Dicyclohexylcarbodiimide|''N'',''{{prime|N}}''-dicyclohexylcarbodiimide]] in ether at low temperature.<ref name=gwu>{{cite journal |doi=10.1021/j100021a022 |title=Formic Anhydride in the Gas Phase, Studied by Electron Diffraction and Microwave and Infrared Spectroscopy, Supplemented with Ab-Initio Calculations of Geometries and Force Fields |journal=The Journal of Physical Chemistry |volume=99 |issue=21 |pages=8589–98 |year=1995 |last1=Wu |first1=G |last2=Shlykov |first2=S |last3=Van Alseny |first3=F. S |last4=Geise |first4=H. J |last5=Sluyts |first5=E |last6=Van Der Veken |first6=B. J }}</ref>