Synthesis and ring-chain isomerism of acid chlorides and amides of 2-(2-pyridyl- and 2-quinolylcarbonyl)benzoic acids

Abstract

The reaction of 2-(2 pyridylcarbonyl)benzoic acid with thionyl chloride affords an unexpected product of the intramolecular acylation of the pyridine nitrogen atom, namely, 6,11-dioxo-6,11-dihydrobenzo[b]quinolizinium chloride. At the same time, 2-(2-quinolylcarbonyl)benzoic acid forms the expected cyclic acid chloride, namely, 3-(2-quitinolyl)-3-chlorophthalide in this reaction. Both compounds acylate ammonia and primary amines, including those with bulky alkyl groups (tert-butyl, 1-adamantyl, and 1,1,3,3-tetramethylbutyl) with the formation of 2-R-3-hydroxy-3-(2-pyridyl- or 2-quinolyl)isoindolines. The protonation of the pyridine nitrogen atom of N-(1,1,3,3-tetramethylbutyl)-2-(2-pyridylcarbonyl)benzamide, obtained in the open amide form, is accompanied by the closing of the isoindotinone ring; the deprotonation is accompanied by ring opening.

How to Cite
Karlivan, G. A.; Batse, A. É.; Valter, R. É. Chem. Heterocycl. Compd. 1994, 30, 438. [Khim. Geterotsikl. Soedin. 1994, 499.]

For this article in the English edition, see DOI https://doi.org/10.1007/BF01169938