The Gould–Jacobs reaction is an organic synthesis for the preparation of quinolines and 4‐hydroxyquinoline derivatives. The Gould–Jacobs reaction is a series of reactions. The series of reactions begins with the condensation/substitution of an aniline with alkoxy methylenemalonic ester or acyl malonic ester, producing anilidomethylenemalonic ester. Then through a 6 electron cyclization process, 4-hydroxy-3-carboalkoxyquinoline is formed, which exist mostly in the 4-oxo form. Saponification results in the formation of an acid. This step is followed by decarboxylation to give 4-hydroxyquinoline. The Gould–Jacobs reaction is effective for anilines with electron‐donating groups at the meta ‐position.
3-775: Walter Abraham Jacobs (December 24, 1883 – July 12, 1967) was an American chemist who discovered the Gould-Jacobs reaction . Much of his career was spent at the Rockefeller Institute for Medical Research , New York City. http://www.encyclopedia.com/doc/1G2-2830904901.html This biographical article about an American chemist is a stub . You can help Misplaced Pages by expanding it . Gould-Jacobs reaction Specifically, 4-quinolinol can be synthesized. In this reaction aniline or an aniline derivative first reacts with malonic acid derivative ethyl ethoxymethylenemalonate with substitution of
6-512: The ethoxy group by nitrogen. A benzannulation takes place by application of heat to a quinoline. The ester group is hydrolysed by sodium hydroxide to the carboxylic acid and decarboxylation again by application of heat to 4-hydroxyquinoline . Extension of the Gould-Jacobs approach can prepare unsubstituted parent heterocycles with fused pyridine ring of Skraup type (see Skraup reaction ). Further reading: The mechanism for
9-526: The Gould–Jacobs reaction begins with a nucleophilic attack from the amine nitrogen follows by the loss of ethanol to form the condensation product. A 6 electron cyclization reaction with the loss of another ethanol molecule forms a quinoline (ethyl 4-oxo-4,4a-dihydroquinoline-3-carboxylate). The enol form can be represented from the keto form through keto-enol tautomerism. Protonation of the nitrogen forms ethyl 4-oxo-1,4-dihydroquinoline-3-carboxylate. An example
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