(1-Ethyl-7-methoxy-2-oxo-1,2-dihydro-quinolin-3-yl)-acetic acid methyl ester → (1-Ethyl-7-hydroxy-2-oxo-1,2-dihydro-quinolin-3-yl)-acetic Acid
Reaction equation
C[O:2][C:3](=[O:20])[CH2:4][C:5]1[C:6](=[O:19])[N:7]([CH2:17][CH3:18])[C:8]2[C:13]([CH:14]=1)=[CH:12][CH:11]=[C:10]([O:15]C)[CH:9]=2>Br.CC(O)=O>[CH2:17]([N:7]1[C:8]2[C:13](=[CH:12][CH:11]=[C:10]([OH:15])[CH:9]=2)[CH:14]=[C:5]([CH2:4][C:3]([OH:20])=[O:2])[C:6]1=[O:19])[CH3:18]Participants
3
Conditions
- Temperature
- 250 °C
Procedure
A suspension of (1-ethyl-7-methoxy-2-oxo-1,2-dihydro-quinolin-3-yl)-acetic acid methyl ester (4.0 g, 14.5 mmol) in 1:1 48% aqueous HBr—HOAc (30 mL) was heated at reflux for 48 h. The resulting solution was cooled to 250° C. and the resulting crystalline solid was stored at 0-50° C. for 2 h, then vacuum filtered, washed with water and air-dried to give the title compound (3.2 g, 89% yield) as tan needles.