反应详情

To a solution of 4-[2-(5-Amino-2-methyl-phenylamino)-oxazol-5-yl]-benzonitrile (558 mg, 2 mmol) and chloroacetaldehyde (50 wt. % in water, 628 mg, 4 mmol) in acetonitril (60 mL), was added at RT NaBH3CN (253 mg, 4 mmol) and dropwise acetic acid (0.4 mL). The mixture was stirred at room temperature 1 h. Ethyl acetate (50 mL) and saturated aqueous NaHCO3 (50 mL) were added. The organic layer was washed with brine (20 mL), dried over MgSO4 and concentrated to give a yellow solid. This was dissolved in toluene (40 mL) and treated with 1-Fluoro-3-isocyanato-benzene (274 mg, 2 mmol) at reflux for 2 h. After evaporation of solvent under reduced vacuum, the crude product was dissolved in isopropanol (60 mL) and treated with potassium tert-butoxide (1.8 g, 16 mmol) at RT for 5 h. Water (20 mL) was added, the organic layer was separated dried over MgSO4 and concentrated. The crude product was silica gel column chromatographed (dichloromethane/ethanol: 95/5) to give 408 mg (45%) of the title compound as a beige solid.

1. washThe organic layer was washed with brine (20 mL)
2. dry with materialdried over MgSO4
3. concentrationconcentrated
4. customto give a yellow solid
5. temperatureat reflux for 2 h
6. customAfter evaporation of solvent under reduced vacuum
7. dissolutionthe crude product was dissolved in isopropanol (60 mL)
8. customthe organic layer was separated
9. dry with materialdried over MgSO4
10. concentrationconcentrated
11. customchromatographed (dichloromethane/ethanol: 95/5)