反应详情

温度

50 °C

To a solution of 2-methoxy-5-(methoxymethoxy)isonicotinaldehyde (1.27 g, 5.29 mol) in THF (5 mL) was added HCl (3 N, 4 mL). The reaction was stirred at 50° C. for 1 h, cooled to RT, and diluted with water (5 mL). The mixture was neutralized to pH 7-8 with solid K2CO3 and the aqueous layer was extracted with EtOAc (100 mL) twice. The combined organic layers were dried over Na2SO4, concentrated, and purified on silica gel using a mixture of EtOAc and hexanes to give 5-hydroxy-2-(2-methoxyethoxy)isonicotinaldehyde (630 mg, 60%) and 5-hydroxy-2-(2-methoxyethoxy)nicotinaldehyde (120 mg, 11%). Data for 5-hydroxy-2-(2-methoxyethoxy)isonicotinaldehyde: 1H NMR (400 MHz, CDCl3) δ 9.98 (s, 1H), 9.50 (s, 1H), 8.07 (s, 1H), 7.02 (s, 1H), 4.51-4.39 (m, 2H), 3.81-3.72 (m, 2H), 3.47 (s, 3H). LRMS (M+H+) m/z 198.1. Data for and 5-hydroxy-2-(2-methoxyethoxy)nicotinaldehyde: NMR (400 MHz, CDCl3) δ 10.3 (s, 1H), 7.99 (d, J=3.2 Hz, 1H), 7.58 (d, J=3.2 Hz, 1H), 7.18-7.07 (br, 1H), 4.54 (dd, J=5.4, 3.7 Hz, 2H), 3.84 (dd, J=5.4, 3.7 Hz, 2H), 3.49 (s, 3H); MS (ESI) m/z 198.1 [M+H]+.

1. temperaturecooled to RT
2. extractionthe aqueous layer was extracted with EtOAc (100 mL) twice
3. dry with materialThe combined organic layers were dried over Na2SO4
4. concentrationconcentrated
5. custompurified on silica gel using
6. additiona mixture of EtOAc and hexanes