反应详情

Add, dropwise, 5.5 mL (8.8 mmol) of a 1.6N solution of butyllithium in hexane in the space of 30 min to a solution of 2.38 g (8.4 mmol) of 1-chloro-2-iodo-4-ethoxybenzene in 50 mL of anhydrous THF cooled under argon to −78° C. After 2 h at −70° C., add 1.74 g (9.2 mmol) of triisopropyl borate and stir the reaction mixture for 3 h at room temperature, then distribute in 200 mL of EtOAc/HCl aq 5N 1:1 mixture. Wash the organic phase with 50 mL of water, dry over Na2SO4 and concentrate under reduced pressure. Purify the residue obtained by silica gel column chromatography, eluting with a DCM/methanol gradient from 0 to 10% of methanol. After concentration under reduced pressure, we obtain 990 mg of (2-chloro-5-ethoxyphenyl)boronic acid, in the form of oil.

1. additionAdd
2. washWash the organic phase with 50 mL of water
3. dry with materialdry over Na2SO4
4. concentrationconcentrate under reduced pressure
5. customPurify the residue
6. customobtained by silica gel column chromatography
7. washeluting with a DCM/methanol gradient from 0 to 10% of methanol
8. concentrationAfter concentration under reduced pressure, we