2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 2-[2-(Cyclopropylmethoxy)-5-(difluoromethyl)phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

2-Bromo-1-cyclopropylmethoxy-4-difluoromethyl-benzene (example B.b18; 24.35 g; 87.9 mmol) is dissolved in dry tert. BuOMe (440 mL). n-BuLi (1.6M in hexane; 60.0 mL; 96.0 mmol) is slowly syringed into the well stirred reaction mixture at −40° C. After one hour commercially available 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (17.86 g; 96.0 mmol) is added at −40° C. followed by stirring at 0° C. for one additional hour. The reaction mixture is quenched by addition of 2M aqueous citric acid (90.0 mL). The organic layer is separated, washed with brine, dried over Mg2SO4 and filtered through a pad of neutral alumina (act.2-3). The solvent is removed under reduced pressure to yield 28.1 g of the title compound as pale yellow oil.

1. customreaction mixture at −40° C
2. stirringby stirring at 0° C. for one additional hour
3. customThe reaction mixture is quenched by addition of 2M aqueous citric acid (90.0 mL)
4. customThe organic layer is separated
5. washwashed with brine
6. dry with materialdried over Mg2SO4
7. filtrationfiltered through a pad of neutral alumina (act.2-3)
8. customThe solvent is removed under reduced pressure

ORD 기록

ord-83874bd30c7e424d9f64c57fe1b14c54

출처 데이터셋

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US08927557B2