反应详情

温度

0 °C

Into 15 mL of dichloromethane, 1.50 g (5.26 mmol) of Compound F and 934 mg (8.42 mmol) of 5-methylisoxazole-3-carboxaldehyde were dissolved, and the solution was cooled to 0° C. in an ice bath. Then, 1.5 mL of acetic acid and 1.78 g (8.42 mmol; 1.6 eq.) of sodium triacetoxyborohydride were added thereto, followed by stirring at room temperature overnight. After completion of the reaction, water was added to the reaction mixture, and a 1.0 mol/L aqueous sodium hydroxide solution was further added thereto to adjust the solution to be basic. Then, the mixture was extracted by adding chloroform, and the organic layer was washed with water and brine, and then dried over anhydrous magnesium sulfate. After evaporation of the solvent, the resulting residue was purified by silica gel column chromatography (2% methanol-chloroform) and then recrystallized from ethanol to obtain 222 mg of Compound 21 as white powder (yield: 11%).

1. additionwas added to the reaction mixture
2. extractionThen, the mixture was extracted
3. additionby adding chloroform
4. washthe organic layer was washed with water and brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customAfter evaporation of the solvent
7. customthe resulting residue was purified by silica gel column chromatography (2% methanol-chloroform)
8. customrecrystallized from ethanol