Phosphorus oxychloride → Ethyl 4,7-dichloroquinoline-3-carboxylate
Reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:15](=O)[C:14]2[C:9](=[CH:10][C:11]([Cl:17])=[CH:12][CH:13]=2)[NH:8][CH:7]=1)=[O:5])[CH3:2].O=P(Cl)(Cl)[Cl:20]>>[CH2:1]([O:3][C:4]([C:6]1[CH:7]=[N:8][C:9]2[C:14]([C:15]=1[Cl:20])=[CH:13][CH:12]=[C:11]([Cl:17])[CH:10]=2)=[O:5])[CH3:2]Participants
3
Procedure
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.
Workup
- concentrationThe resulting black solution was then concentrated in vacuo
- dissolutionthe residue was dissolved in 100 ml of acetone
- additionIt was poured onto 1 kg of ice
- extractionThe mixture was then extracted with 3×125 ml of CH2Cl2
- dry with materialthe pooled extracts were dried over Na2SO4
- concentrationconcentrated to a black solid
- customthat was dried in vacuo overnight
Sources & evidence
- ORD record
- ord-24fefd22d94241c39ac1a33cd8dee0bf
- Source dataset
- uspto-grants-1995_08
- Patent number
- US05438064
Reaction notes
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