反应详情

4,5-Diamino-3-fluoro-2-phenylamino-benzoic acid methyl ester 6c (0.20 g, 0.73 mmol) is suspended in ethanol (3 mL) and 5 M aqueous NCl (1 mL, 5.00 mmol) is added. The reaction mixture is brought to reflux under N2 and then 2,4-pentanedione (0.150 mL, 1.45 mmol) is added. The reaction mixture is stirred at reflux for 60 minutes. The reaction mixture is cooled to room temperature and treated with saturated aqueous NaHCO3 until the pH of the reaction mixture is pH 7 and is then concentrated under reduced pressure to dryness. The residue is diluted with ethyl acetate and water, poured into a separatory funnel and the layer separated. The ethyl layer is washed with brine, dried (Na2SO4) and concentrated under reduced pressure. The red solid residue is triturated with diethyl ether to yield a light brown solid and red filtrate. The solid is collected and washed with diethyl ether to yield 0.20 g (91%) of the pure desired product as a light brown solid. MS ESI (+) m/z 300 (M+1) detected.

1. addition5 M aqueous NCl (1 mL, 5.00 mmol) is added
2. temperatureto reflux under N2
3. temperatureat reflux for 60 minutes
4. concentrationis then concentrated under reduced pressure to dryness
5. additionThe residue is diluted with ethyl acetate and water
6. additionpoured into a separatory funnel
7. customthe layer separated
8. washThe ethyl layer is washed with brine
9. dry with materialdried (Na2SO4)
10. concentrationconcentrated under reduced pressure
11. customThe red solid residue is triturated with diethyl ether
12. customto yield a light brown solid and red filtrate
13. customThe solid is collected
14. washwashed with diethyl ether