Thiophene-2-carboxylic acid

Thiophene-2-carboxylic acid
Names
	Other names 2-thenoic acid; tenoic acid; Rhinotrophyl
Identifiers
CAS Number	527-72-0 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:71241;
ChEMBL	ChEMBL1222314;
ChemSpider	10250;
ECHA InfoCard	100.007.659
EC Number	208-423-4;
KEGG	D08568;
PubChem CID	10700;
UNII	3FD00JX53J;
CompTox Dashboard (EPA)	DTXSID2060177 ;
	InChI InChI=1S/C5H4O2S/c6-5(7)4-2-1-3-8-4/h1-3H,(H,6,7) Key: QERYCTSHXKAMIS-UHFFFAOYSA-N;
	SMILES C1=CSC(=C1)C(=O)O;
Properties
Chemical formula	C5H4O2S
Molar mass	128.15 g·mol−1
Appearance	white solid
Melting point	125–127 °C (257–261 °F; 398–400 K)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Thiophene-2-carboxylic acid is an organic compound with the formula SC₄H₃CO₂H. It is one of two monocarboxylic acids of thiophene, the other being thiophene-3-carboxylic acid.^[1] Copper(I) thiophene-2-carboxylate is a catalyst for Ullmann coupling reactions.

Synthesis

It can be prepared by the oxidation of thiophene-2-carboxaldehyde or, more practically, 2-acetylthiophene.^[2]

Applications and reactions

Suprofen, which is produced from thiophene-2-carboxylic acid, is the active ingredient in some eye drops.^[2]

Upon treatment with LDA, thiophene-2-carboxylic acid undergoes double deprotonation to give the 5-lithio derivative, a precursor to many 5-substituted derivatives.^[3]

Thiophene-2-carboxylic acid has been widely studied as a substrate in coupling reactions and olefinations.^[4]^[5]

References

^ E. Campaigne, William M. LeSuer (1953). "3-Thenoic Acid". Organic Syntheses. 33: 94. doi:10.15227/orgsyn.033.0094.
^ ^a ^b Swanston, Jonathan (2006). "Thiophene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_793.pub2. ISBN 3527306730..
^ Knight, David W.; Nott, Andrew P. (1983). "Generation and Synthetic Utility of Dianions Derived from Thiophenecarboxylic Acids". Journal of the Chemical Society, Perkin Transactions 1: 791–4. doi:10.1039/p19830000791.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Gooßen, Lukas J.; Deng, Guojun; Levy, Laura M. (2006). "Synthesis of Biaryls via Catalytic Decarboxylative Coupling". Science. 313 (5787): 662–664. Bibcode:2006Sci...313..662G. doi:10.1126/science.1128684. PMID 16888137. S2CID 1781760.
^ Rakshit, Souvik; Grohmann, Christoph; Besset, Tatiana; Glorius, Frank (2011). "Rh(III)-Catalyzed Directed C−H Olefination Using an Oxidizing Directing Group: Mild, Efficient, and Versatile". Journal of the American Chemical Society. 133 (8): 2350–2353. doi:10.1021/ja109676d. PMID 21275421.

[1] E. Campaigne, William M. LeSuer (1953). "3-Thenoic Acid". Organic Syntheses. 33: 94. doi:10.15227/orgsyn.033.0094.

[Ullmann-2] Swanston, Jonathan (2006). "Thiophene". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a26_793.pub2. ISBN 3527306730..

[3] Knight, David W.; Nott, Andrew P. (1983). "Generation and Synthetic Utility of Dianions Derived from Thiophenecarboxylic Acids". Journal of the Chemical Society, Perkin Transactions 1: 791–4. doi:10.1039/p19830000791.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[4] Gooßen, Lukas J.; Deng, Guojun; Levy, Laura M. (2006). "Synthesis of Biaryls via Catalytic Decarboxylative Coupling". Science. 313 (5787): 662–664. Bibcode:2006Sci...313..662G. doi:10.1126/science.1128684. PMID 16888137. S2CID 1781760.

[5] Rakshit, Souvik; Grohmann, Christoph; Besset, Tatiana; Glorius, Frank (2011). "Rh(III)-Catalyzed Directed C−H Olefination Using an Oxidizing Directing Group: Mild, Efficient, and Versatile". Journal of the American Chemical Society. 133 (8): 2350–2353. doi:10.1021/ja109676d. PMID 21275421.

[1]

[2]

[3]

[4]

[5]