Triisopropyl borate → 6-methyl-1H-spiro[2,1-benzoxaborole-3,1'-cyclopentane]-1-ol

Temperature

-78 °C

To a solution of 2-bromo-1-(1-(methoxymethoxy)cyclopentyl)-4-methylbenzene (2.2 g, 714 mmol) in THF (40 mL) at −78° C. was added n-BuLi (7.5 mL, 18.5 mmol) dropwise. The mixture was stirred at −78° C. for additional 1 h and then triisopropyl borate (2.8 g, 14.8 mmol) in 10 mL of THF was added below −70° C. The resulting mixture was kept stirring at −78° C. for 30 min and allowed to warm to rt and stirred overnight. Then it was quenched with aqueous NH4Cl and extracted with ethyl acetate. The organic layer was dried over Na2SO4 and concentrated under reduced pressure. The residue was purified on column chromatography to provide the product (1.2 g, yield 81%).

1. stirringThe resulting mixture was kept stirring at −78° C. for 30 min
2. temperatureto warm to rt
3. stirringstirred overnight
4. customThen it was quenched with aqueous NH4Cl
5. extractionextracted with ethyl acetate
6. dry with materialThe organic layer was dried over Na2SO4
7. concentrationconcentrated under reduced pressure
8. customThe residue was purified on column chromatography

ORD record

ord-3133943e798f4dcca940ac9e4463deb5

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08546357B2