2-quinolinones synthesis

Pyrimido[4,5-6]quinolinium salts pseudo bases - ring opening, 3, 208 Pyrimido[4,5-6]quinolinium salts, 4-chloro-hydrolysis, 3, 214 Pyrimido[4,5-6]quinolinones synthesis, 3, 228 Pyrimido[4,5 -6]quinolin-5-ones synthesis, 3, 221-222 Pyrimidothiadi azoles reactions, 6, 533 Pyrimidothiazines synthesis, 4, 527 Pyrimidothiazinones mass spectra, 2, 23... 

Scheme 2.4 Application of an asymmetric Buchwald-Hartwig reaction for atropisomeric 2-aryl-4-quinolinone synthesis by Takahashi ef al. [30].

Hydroarylation using an ionic liquid and Hf(OTf)4 catalyst can be employed in quinolinone synthesis [26]. The intramolecular hydroarylation of phenylpropiolic acid 3,4,5-trimethoxyanilide in [bmimllSbFsl and methylcyclohexane is catalyzed by 10 mol % Hf(OTf)4 and affords the corresponding quinolinone in 72% yield (Scheme 18.32). 

Li et al. developed a new route to quinolinone synthesis catalyzed by Cu(acac)2 through oxidative (sp3)-H functionalization-carbocyclization-ketonization cascade (Scheme 8.94). This efficient protocol provides a new pathway to synthesize the quinolinone framework via implanting an oxygen atom from molecular oxygen. The desired quinolinones could be obtained in moderate to good yields under the mild conditions [166]. 

Scheme 8.94 Quinolinone synthesis through oxidative (sp3)-H functionalization-...

Table 15.30 2-Quinolinone synthesis from carbonylative [3-1-2-I-1] annulation of A/-pyridyl anilines with internal alkynes and Mo(CO)gi k...

Lewis-acid-catalyzed Diels-Alder reaction of 3-phenylthio-2- quinolinones with silox-ydiene. Synthesis of the intermediate for dynemicin A core [97]... 

Chiral butyrolactones of type 27 and 28 have substantial value in asymmetric synthesis because they contain readily differentiable difunctional group relationships e.g. 1,5-di-carboxylic acid, 1,4-hydroxy carboxylic acid, 1,6-hydroxy-carboxylic acid, 1,6-diol etc.) that would be difficult to assemble by existing asymmetric condensation and pericyclic processes. Applications of these chiral derivatives of glutaric acid to syntheses of indole, indoline and quinolinone alkaloids are illustrated in Schemes 16-18. 

Lipson VV, Shirobokova MG, Shishkin OV et al (2006) Synthesis of partially hydrogenated pyrazolo[3, 4-b]quinolinones by condensation of 3-amino-5-methylpyrazole with aromatic aldehydes and dimedone. Russ J Org Chem 42(7) 1015-1021... 

A palladium-catalyzed amidation of halo(hetero)aromatics substituted in the ortAo-position by a carbonyl function with a primary or secondary amine has been introduced as an alternative to the Friedlander condensation for the synthesis of naphthyridinones (and quinolinones) (Scheme 32) <2004OL2433>. 

The most frequently used synthesis of 4-quinolinones is the Conrad-Limpach cyclization (77HC(32)I39, 77HC(32)146) and its modification due to Gould and Jacobs (Scheme 11) (92T7373). 

A number of other miscellaneous transformations of hetero-aromatic A-oxides have been reported. Of particular interest is the application189 of the photolysis of 2-cyanoquinoline 1-oxides to the synthesis of 1-aminocarbostyrils 2-cyano-4-methylquinoline 1-oxide is converted into the quinolinone by irradiation in dichloromethane solution in the presence of a secondary amine, and the conversion presumably takes place via the intermediate oxaziridine [Eq. (45)]. 

The intramolecular version of this reaction provides a general method for synthesis of biologically active heterocycles, for example coumarins, quinolinones, and thiocoumarins, as shown in Schemes 7 and 8 [3a, c]. The reaction tolerates a variety of functional groups, for example Br, CHO, etc. 

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