反应详情

温度

90 °C

To a solution of 2-(1,3-dioxolan-2-yl)-5-fluoropyridin-3-amine (5 g, 27.14 mmol) in DMSO: H2O (1:1) (162 mL) was added lithium chloride (6.9 g, 162.89 mmol). The reaction mixture was heated to 90° C. for 16 h and water was removed using dean-stark apparatus. Water was added to the reaction mass and extracted with EtOAc. Organic layer was washed with brine and dried over Na2SO4. The organic layer was concentrated in vacuo and purified by column chromatography on silica gel using 0-40% EtOAc in hexane to give 3-amino-5-fluoropicolinaldehyde: 1H NMR (400 MHz, DMSO-d6): δ 7.003-7.037 (m, 1H), 7.387 (br s, 2H), 7.944 (d, 1H, J=2.4 Hz), 9.853 (s, 1H); LC-MS (ESI) m/z 141.0 [M+H]+.

1. customwater was removed
2. additionWater was added to the reaction mass
3. extractionextracted with EtOAc
4. washOrganic layer was washed with brine
5. dry with materialdried over Na2SO4
6. concentrationThe organic layer was concentrated in vacuo
7. custompurified by column chromatography on silica gel using 0-40% EtOAc in hexane