Diphenyl Ether → 6-Bromo-1,4-dihydroquinolin-4-one

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][C:6](C(O)=O)=[C:5]2[OH:15].C1(OC2C=CC=CC=2)C=CC=CC=1>CO.C(OCC)C>[Br:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][CH:6]=[C:5]2[OH:15]

Participants

Procedure

The solid 6-bromo-4-hydroxy-quinoline-3-carboxylic acid (102.59 g, 337.7 mmol) was added to hot diphenyl ether (508 g) and then the mixture was heated to reflux for 9 h to afford a light brown suspension. After cooling to room temperature, the mixture was diluted with methanol (20 mL) and diethyl ether (300 mL). Then, the solids were collected by filtration and washed with diethyl ether. After drying in air, 72.43 g (95% yield) of 6-bromo-quinolin-4-ol was isolated as a white solid: EI-HRMS m/e calcd for C9H6BrNO (M+) 222.9633, found 222.9630.