反应详情

A 2.77 M solution of n-butyllithium in hexane (30.7 mL) was added dropwise to a solution containing 2-bromofluorobenzene (15.6 g) in THF/toluene (50 mL/150 mL) under a nitrogen atmosphere at −78° C. The reaction solution was stirred at the same temperature for 1 h. A boron trifluoride-diethyl ether complex (10.7 mL) was added dropwise to a solution containing (±)-3a,4-dihydro-3H,6H-furo[3,4-c]isoxazole (4.8 g) in toluene (350 mL) under a nitrogen atmosphere at −78° C. Previously prepared 2-fluorophenyllithium was added dropwise to the reaction solution at the same temperature. After stirring at the same temperature for 1 h, aqueous ammonium chloride was added to the reaction solution, and the reaction solution was warmed to RT. Water and EtOAc were added to the reaction solution, and the organic layer was separated. The organic layer was washed with a saturated sodium chloride solution. The organic layer was dried over anhydrous MgSO4, and the insoluble matter was separated by filtration. The filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound (5.6 g). 1H NMR (400 MHz, CDCl3) δ ppm 3.39-3.45 (m, 1H), 3.52-3.62 (brm, 1H), 3.84-3.92 (brm, 2H), 3.98 (brd, J=9.2 Hz, 1H), 4.16 (ddd, J=2.4, 6.4, 11.2 Hz, 1H), 4.50-4.58 (brm, 1H), 5.11 (brs, 1H), 7.06 (ddd, J=1.2, 8.4, 11.6 Hz, 1H), 7.16 (ddd, J=1.2, 7.6, 7.6 Hz, 1H), 7.25-7.31 (m, 1H), 7.84-7.95 (m, 1H).

1. additionA boron trifluoride-diethyl ether complex (10.7 mL) was added dropwise to a solution
2. stirringAfter stirring at the same temperature for 1 h
3. customthe organic layer was separated
4. washThe organic layer was washed with a saturated sodium chloride solution
5. dry with materialThe organic layer was dried over anhydrous MgSO4
6. customthe insoluble matter was separated by filtration
7. concentrationThe filtrate was concentrated under reduced pressure
8. customThe residue was purified by silica gel column chromatography