Phosphorus oxychloride → Ethyl 6-bromo-4-chloroquinoline-3-carboxylate
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][C:9]2[C:14]([C:15]=1O)=[CH:13][C:12]([Br:17])=[CH:11][CH:10]=2)=[O:5])[CH3:2].P(Cl)(Cl)([Cl:20])=O>CN(C)C=O>[Br:17][C:12]1[CH:13]=[C:14]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])=[C:15]2[Cl:20]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Suspend 6-bromo-4-hydroxyquinoline-3-carboxylic acid ethyl ester (11 g, 37 mmol) in anhydrous dimethylformamide (148.6 mL) under nitrogen atmosphere. Add phosphoryl chloride (20.7 mL, 222 mmol, 6 eq.) via syringe over 5 minutes and stir vigorously at room temperature for 3 hours. Quench the reaction by pouring the mixture into ice water (1.5 L) and continue stirring until all the ice has melted. Obtain the solid formed by filtration, rinse with water and allow complete drying to afford the titled compound (11.4 g, 94%). MS (ESI) m/z (M+H)+ 314.0, 316.0.