反应详情

Ethyl 2,4-dimethoxyquinoline-3-carboxylate (1.5 g, 5.7 mmol) was heated at reflux in NaOH solution (10%, 100 mL) for 1 h. After cooling, the mixture was acidified with concentrated HCl to pH 4. The resulting precipitate was collected via filtration and washed with water and ether to give 2,4-dimethoxyquinoline-3-carboxylic acid (A-17) as a white solid (670 mg, 50%). 1H NMR (CDCl3) δ 8.01-8.04 (d,J=12 Hz, 1 H), 7.66-7.76 (m, 2 H), 7.42-7.47 (t,J=22 Hz, 2 H), 4.09 (s, 3 H). 3.97 (s, 3 H); ESI-MS 234.1 m/z (MH+).

1. temperatureAfter cooling
2. filtrationThe resulting precipitate was collected via filtration
3. washwashed with water and ether