反応 #45782

反応方程式

O-acetylsalicyloyl chloride

Diisopropylethylamine

dichloromethane

4-amino-6-fluoro-5-hydroxy-2-methyl-biphenyl-3-carbonitrile

→

compound

収率 64.0%

7-Fluoro-2-(2-hydroxyphenyl)-5-methyl-6-phenyl-1,3-benzoxazole-4-carbonitrile

収率 64.0%

溶媒

water

反応条件

後処理

1. 1
   workup.ADDITIONwas added
2. 2
   workup.ADDITIONwas added
3. 3
   抽出followed by extraction with ethyl acetate
4. 4
   洗浄The organic layer was washed with saturated brine
5. 5
   乾燥dried over anhydrous sodium sulfate
6. 6
   その他the solvent was evaporated away under reduced pressure
7. 7
   温度In xylene (30 ml) and in the presence of a catalytic amount of p-tosylic acid, the resulting residue was heated
8. 8
   温度under reflux for 2 hours with a Dean-Stark device
9. 9
   温度After cooling
10. 10
    その他the solvent was evaporated away
11. 11
    workup.DISSOLUTIONthe resulting residue was dissolved in chloroform
12. 12
    洗浄washed with saturated sodium bicarbonate water
13. 13
    乾燥dried over anhydrous sodium sulfate
14. 14
    その他the solvent was evaporated away under reduced pressure
15. 15
    洗浄The resulting residue was washed with a mixed solvent of isopropyl ether and ethanol
16. 16
    その他the solid was collected by nitration

実験手順

Diisopropylethylamine (435 μl, 2.5 mmol) was added to a dichloromethane (10 ml) solution of 4-amino-6-fluoro-5-hydroxy-2-methyl-biphenyl-3-carbonitrile (I-41) (353 mg, 1.46 mmol), then after cooling with ice, O-acetylsalicyloyl chloride (318 mg, 1.6 mmol) was added, followed by stirring at the same temperature for 30 minutes. With cooling with ice, water was added, followed by extraction with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, then the solvent was evaporated away under reduced pressure. In xylene (30 ml) and in the presence of a catalytic amount of p-tosylic acid, the resulting residue was heated under reflux for 2 hours with a Dean-Stark device. After cooling, the solvent was evaporated away, and the resulting residue was dissolved in chloroform, washed with saturated sodium bicarbonate water, then dried over anhydrous sodium sulfate, and the solvent was evaporated away under reduced pressure. The resulting residue was washed with a mixed solvent of isopropyl ether and ethanol, and the solid was collected by nitration to obtain the entitled compound (320 mg, 64%) as a pale yellow solid.

出典