Trimethyl borate → 3,3-bis(fluoromethyl)-5-methylbenzo[c][1,2]oxaborol-1(3H)-ol

To a solution of 1-bromo-2-(2-(ethoxymethoxy)-1,3-difluoropropan-2-yl)-4-methylbenzene (1.8 g, 5.10 mmol) in THF (15 mL) at −78° C. was slowly added n-BuLi (5.1 mL, 12.75 mmol). After stirring for 10 min, a solution of B(OMe)3 (1.06 g, 10.2 mmol) in dry THF (5 mL) was added dropwise. The mixture was stirred at −78° C. for 0.5 h, and then dry ice bath was removed. The solution was acidified with HCl (4 N) and extracted with EA (100 mL×2). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by column chromatography over silica gel eluted with PE:EA (5:1 to 3:1) to give the desired compound (350 mg, yield 32%) as white solid.

1. customat −78° C.
2. stirringThe mixture was stirred at −78° C. for 0.5 h
3. customdry ice bath was removed
4. extractionextracted with EA (100 mL×2)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure
9. customThe residue was purified by column chromatography over silica gel
10. washeluted with PE

ORD record

ord-83816ec589a74581bcdd58fd995b6284

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08853186B2