反应详情

To stirred 90° C. polyphosphoric acid (150 g) was added 10.72 g (7.65 mmol) of 3-fluorobenzoic acid and 6.98 g (7.5 mmol) of aniline and the bath temperature raised to 180°-190° C. and held there for 1 hour. A solution was obtained at about 130° C. The heating bath was removed and the stirred mixture (sublimate above the solution) was treated cautiously with 60 mL of water. The mixture was stirred at 140°-155° C. for 1 hour, the heating bath removed, 50 mL of 3N HCl added, the mixture poured into 750 mL of water and filtered through a pad of Celite. The filtrate was basified with 15% sodium hydroxide and the resulting solid extracted with methylene chloride. The dried (MgSO4) solution was filtered and the solvent removed to yield a brown solid. Recrystallization from ethanol-hexane (1:3) returned a greenish yellow solid that was chromatographed on silica gel (methylene chloride) to yield 4.83 g (30%) of yellow 4-amino-3'-fluorobenzophenone, mp 98°-100° C. 1H NMR (300 MHz, CDCl3): 4.21 (s, 2H, NH2) 6.66-6.70 (m, 2H, aromatic) 7.23-7.26 (m, 1H, aromatic) 7.39-7.51 (m, 3H, aromatic) 7.69-7.72 (m, 2H, aromatic). MS (CI, CH4): 216 (M+1).

1. temperaturethe bath temperature raised to 180°-190° C.
2. customA solution was obtained at about 130° C
3. customThe heating bath was removed
4. additionthe stirred mixture (sublimate above the solution) was treated cautiously with 60 mL of water
5. customthe heating bath removed
6. addition50 mL of 3N HCl added
7. additionthe mixture poured into 750 mL of water
8. filtrationfiltered through a pad of Celite
9. extractionthe resulting solid extracted with methylene chloride
10. dry with materialThe dried (MgSO4) solution
11. filtrationwas filtered
12. customthe solvent removed
13. customto yield a brown solid
14. customRecrystallization from ethanol-hexane (1:3)
15. customthat was chromatographed on silica gel (methylene chloride)