反应详情

7-Chloro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid ethyl ester [76.0 g, 302 mmol, prepared as described by C. C. Price et al in J. Am. Chem. Soc., 68, 1204 (1946)]was refluxed for 4.5 h in 310 ml of POCl3. The resulting black solution was then concentrated in vacuo and the residue was dissolved in 100 ml of acetone. It was poured onto 1 kg of ice and brought to pH 7 with 50% NaOH. The mixture was then extracted with 3×125 ml of CH2Cl2 and the pooled extracts were dried over Na2SO4 and concentrated to a black solid that was dried in vacuo overnight affording 74.7 g (276 mmol, 92% crude yield) of 4,7-dichloro-3-quinolinecarboxylic acid ethyl ester that was used in the next step without purification.

1. concentrationThe resulting black solution was then concentrated in vacuo
2. dissolutionthe residue was dissolved in 100 ml of acetone
3. additionIt was poured onto 1 kg of ice
4. extractionThe mixture was then extracted with 3×125 ml of CH2Cl2
5. dry with materialthe pooled extracts were dried over Na2SO4
6. concentrationconcentrated to a black solid
7. customthat was dried in vacuo overnight