Phosphorus oxychloride → Ethyl 4-chloro-6-methoxyquinoline-3-carboxylate
Reaction equation
O[C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[N:5]=[CH:4][C:3]=1[C:14]([O:16][CH2:17][CH3:18])=[O:15].O=P(Cl)(Cl)[Cl:21]>>[Cl:21][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([O:12][CH3:13])[CH:10]=2)[N:5]=[CH:4][C:3]=1[C:14]([O:16][CH2:17][CH3:18])=[O:15]Participants
3
Procedure
A solution of ethyl 4-hydroxy-6-methoxyquinoline-3-carboxylate (Example 1c, 1.24 g, 5.0 mmol) in POCl3 was refluxed under nitrogen for 3 hrs. The solution was cooled to room temperature and evaporated under reduced pressure. The residue was carefully quenched with ice, and neutralized with 2.0 N NaOH to pH 7. The precipitate was collected by filtration, washed with cold water, and dried under vacuum to give the title compound as a pale-yellow solid (1.29 g, 97%). 1H NMR (400 MHz, DMSO-d6) δ 1.36 (t, J=7.0 Hz, 3H), 3.96 (s, 3H), 4.41 (q, J=7.0 Hz, 2H), 7.57 (d, J=2.8 Hz, 1H), 7.61 (dd, J=2.8, 8.8 Hz, 1H), 8.05 (d, J=8.8 Hz, 1H), 8.97 (s, 1H). MS 266, 268 (MH+).
Workup
- customevaporated under reduced pressure
- customThe residue was carefully quenched with ice
- filtrationThe precipitate was collected by filtration
- washwashed with cold water
- customdried under vacuum
Sources & evidence
- ORD record
- ord-e336bd9628a84040b3391a07f404a2f4
- Source dataset
- uspto-grants-2015_04
- Patent number
- US09000054B2
Reaction notes
Loading…