Potassium Carbonate → 2-Chloro-6-bromo-7,8-dihydro-5-quinolinone

HRID 1196568Notes

Reaction equation

HRID 1196568 reaction equation
[Cl:1][C:2]1[CH:11]=[CH:10][C:9]2[C:8](=[O:12])[CH2:7][CH2:6][CH2:5][C:4]=2[N:3]=1.[Br:13]Br.C(=O)([O-])[O-].[K+].[K+]>C(Cl)(Cl)Cl>[Cl:1][C:2]1[CH:11]=[CH:10][C:9]2[C:8](=[O:12])[CH:7]([Br:13])[CH2:6][CH2:5][C:4]=2[N:3]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 24408BromineHCID 5928392-Chloro-5,6,7,8-tetrahydroquinolin-5-one

Product 1

HCID 198986932-Chloro-6-bromo-7,8-dihydro-5-quinolinone

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

3-Aminocyclohex-2-enone (ex Aldrich) was reacted with methyl propiolate (ex Lancaster) to give 7,8-dihydro-2,5-quinoline-dione according to Speckamp et al J. Trav. Chem. Pays. bas., 91 157 (1972). The latter was converted to 2-chloro-7,8-dihydro-5-quinolinone by analogy with Example VI. The latter compound (2 g) was dissolved in chloroform (200 ml) and treated with bromine (0.53 ml) dropwise at room temperature. After 30 min solid potassium carbonate was added, the mixture was stirred for 1 hour, filtered and solvent removed to give 2-chloro-6-bromo-7,8-dihydro-5-quinolinone (2.86 g). This compound was heated at 110° C. with anhydrous lithium chloride (1.4 g) and dimethylformamide (45 ml) for 3 hours. The mixture was diluted with water, worked-up in conventional fashion and purified by column chromatography on silica (eluting with ether-hexane) to give 2-chloro-5-hydroxyquinoline (0.77 g).

Workup

  1. filtrationfiltered
  2. customsolvent removed

Sources & evidence

ORD record
ord-9dac892f91884888926c5e412e79e9ea
Source dataset
uspto-grants-1992_05
Patent number
US05114940

Reaction notes

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