Phosphorus oxychloride → Ethyl 4-chloro-6-methoxyquinoline-3-carboxylate

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Reaction Steps

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+).

Provenance & Evidence