Heterocyclic ketones in the pfitzinger reaction

• Published in: Russian journal of general chemistry Vol. 81; no. 2; pp. 397 - 404
• Main Authors: Moskalenko, A. I., Boeva, A. V., Boev, V. I.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.02.2011; Springer Nature
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry, Multidisciplinary; Chemistry/Food Science; Physical Sciences; Science & Technology; Compound XIII; Quinoline; Acid VIII; Heterocyclic Ketone; Isatin; QUINOLINES; RECENT PROGRESS
• ISSN: 1070-3632; 1608-3350
• DOI: 10.1134/S1070363211020198

By the reaction of isatin with heterocyclic ketones ( N - tert -butoxycarbonyl derivatives of pyrrolidin-3-one, piperidin-4-one, piperidin-3-one, 1,2,3,4-tetrahydroquinolin-4-one, 8-azabicyclo[3.2.1]octan-3-one, tetrahydropyran-4-one, tetrahydrobenzopyran-4-one) in the presence of KOH (the Pfitzinger reaction) were synthesized quinoline-4-carboxylic acids [4,3]fused with the respective heterocycles. These acids were involved in the reactions with diazomethane and amines at the carboxy group leading to methyl esters and amides, respectively. The esters obtained reacted with hydrazine hydrate affording the acid hydrazides, which entered in the condensation with benzaldehyde to form phenylhydrazones. The esters and amides containing N-tert -butoxycarbonyl fragment lost the tert -butoxycarbonyl group easily to form the secondary amines dihydrochlorides, the [4,3]fused quinoline-4-carboxylic acid derivatives.