:Friedländer synthesis

{{Use dmy dates|date=February 2024}}

{{Reactionbox

| Name = Friedländer synthesis

| Type = Ring forming reaction

| NamedAfter = Paul Friedländer

| Section3 = {{Reactionbox Identifiers

| OrganicChemistryNamed = friedlaender-synthesis

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The Friedländer synthesis is a chemical reaction of 2-aminobenzaldehydesOrganic Syntheses, Coll. Vol. 3, p.　56 (1955); Vol. 28, p.　11 (1948). ([http://www.orgsyn.org/orgsyn/prep.asp?prep=cv3p0056 Article]) with ketones to form quinoline derivatives.{{cite journal|author=Friedländer, P. |journal=Chemische Berichte|year=1882|volume=15|pages= 2572–2575|doi=10.1002/cber.188201502219|title=Ueber o-Amidobenzaldehyd|issue=2|url=https://zenodo.org/record/1425274}}{{cite journal|author1=Friedländer, P. |author2=Gohring, C. F. |journal=Ber.|year=1883|volume=16|pages= 1833–1839|doi=10.1002/cber.18830160265|title=Ueber eine Darstellungsmethode im Pyridinkern substituirter Chinolinderivate|issue=2|url=https://zenodo.org/record/1425313 }} It is named after German chemist Paul Friedländer (1857–1923).

Image:Friedlaender Synthesis Scheme V.1.svg

This reaction has been catalyzed by trifluoroacetic acid,{{cite journal|author1=Shaabani, A. |author2=Soleimani, E. |author3=Badri, Z. |doi=10.1080/00397910601055230|title=Triflouroacetic Acid as an Efficient Catalyst for the Synthesis of Quinoline|year=2007|journal=Synthetic Communications|volume=37|issue=4|pages=629–635|s2cid=98625429 }} toluenesulfonic acid,{{cite journal|author1=Jia, C.-S. |author2=Zhang, Z. |author3=Tu, S.-J. |author4=Wang, G.-W. |journal=Org. Biomol. Chem.|year=2006|volume=4|pages= 104–110|doi=10.1039/b513721g|title=Rapid and efficient synthesis of poly-substituted quinolines assisted by p-toluene sulphonic acid under solvent-free conditions: Comparative study of microwave irradiation versus conventional heating|issue=1 |pmid=16358003 }} iodine,{{cite journal|author1=Wu, J. |author2=Xia, H.-G. |author3=Gao, K. |journal=Org. Biomol. Chem.|year=2006|volume=4|pages= 126–129|doi=10.1039/b514635f|title=Molecular iodine: A highly efficient catalyst in the synthesis of quinolines via Friedländer annulation|issue=1 |pmid=16358006 }} and Lewis acids.{{cite journal|author1=Varala, R. |author2=Enugala, R. |author3=Adapa, S. R. |journal=Synthesis|year=2006|pages= 3825–3830 | doi = 10.1055/s-2006-950296 |volume=2006 |issue=22 |title=Efficient and Rapid Friedlander Synthesis of Functionalized Quinolines Catalyzed by Neodymium(III) Nitrate Hexahydrate}}

Several reviews have been published.{{cite journal|author=Manske, R. H. |journal=Chem. Rev.|year=1942|volume=30|pages= 113–144|doi=10.1021/cr60095a006|title=The Chemistry of Quinolines}}{{cite journal|author=Bergstrom, F. W. |journal=Chem. Rev.|year=1944|volume=35|pages= 77–277|doi=10.1021/cr60111a001|title=Heterocyclic Nitrogen Compounds. Part IIA. Hexacyclic Compounds: Pyridine, Quinoline, and Isoquinoline|issue=2}}{{cite book|author1=Cheng, C.-C. |author2=Yan, S.-J. |doi=10.1002/0471264180.or028.02|chapter=The Friedländer Synthesis of Quinolines|title=Organic Reactions|year=2004|isbn=0471264180}}