反应详情

To a stirring solution of 4-bromo-2-chloro-5-fluorobenzoic acid (50 g, 0.25 mol) in 200 mL of EtOAc at 0° C. (ice/water bath) was added triethyl amine (237 mL, 0.50 mol), pyrrolidine (41.2 mL, 0.5 mol), followed by 2,4,6-tripropyl-1,3,5,2,4,6-trioxatriphosphorinane-2,4,6-trioxide (CAS #68957-94-8) (237 mL, 0.37 mol, 50 wt %, EtOAc). After 1 hr, the reaction was quenched with a saturated solution of NaHCO3, and extracted with EtOAc, and CH2Cl2. The combined organic layers were dried over MgSO4, filtered and concentrated. Purification of this material was accomplished by flash column chromatography using a Biotage™ 75 L column, eluting with a gradient of 2%-50% EtOAc/hexanes. The product containing fractions were collected and concentrated to give the title compound (52 g, 68% yield) as a white solid: Rf=0.23 (40% EtOAc/hexanes); LRMS m/z Calcd for C11H10BrClFNO, 306.6, found, 306, 308, 310 (M+1) APCI; 1H NMR (300 MHz, CDCl3): δ 7.53 (d, J=6.2 Hz, 1H), 7.02 (d, J=7.9 Hz, 1H), 3.54 (apt t, J=6.6 Hz, 2H), 3.13 (apt t, J=6.6 Hz, 2H), 1.92-1.83 (m, 4H); 100 MHz 13C NMR (CDCl3) δ 164.5, 158.1 (d, JC-F=249.5 Hz), 138.2, 134.3, 126.0, 115.5 (d, JC-F=25.5 Hz), 110.3 (d, JC-F=22.5 Hz), 47.0, 45.8, 26.0, 24.6.

1. customthe reaction was quenched with a saturated solution of NaHCO3
2. extractionextracted with EtOAc, and CH2Cl2
3. dry with materialThe combined organic layers were dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. customPurification of this material
7. washeluting with a gradient of 2%-50% EtOAc/hexanes
8. additionThe product containing fractions
9. customwere collected
10. concentrationconcentrated