Triisopropyl borate → 3-(Neopentyloxysulfonyl)phenylboronic acid

Step 2) To a solution of the above prepared 3-bromo-benzenesulfonic acid 2,2-dimethyl-propyl ester (9.83 g, 32 mmol) and triisopropyl borate (13.4 mL, 58 mmol) in THF (45 mL) at −78° C. was added n-BuLi (1.6 M in hexane, 20 mL, 32 mmol) keeping the internal temperature below −65° C. Stirring was continued at −78° C. for 1 h, then more n-BuLi (4.0 mL, 6.4 mmol) was added and stirring was continued at −78° C. for 30 min. The reaction mixture was quenched with 1 M H2SO4-sol. (40 mL), allowed to quickly (waterbath) warm to ca. 20° C. and stirred for 10 min. Diluted with EtOAc, layers were separated, washed organic layer with brine and dried over Na2SO4. Removal of the solvent in vacuum left the title compound as white solid (9.00 g, 103%). MS (ISN) 271.4 [(M−H)−].

1. customthe internal temperature below −65° C
2. stirringstirring
3. waitwas continued at −78° C. for 30 min
4. customThe reaction mixture was quenched with 1 M H2SO4-sol
5. stirringstirred for 10 min
6. additionDiluted with EtOAc, layers
7. customwere separated
8. washwashed organic layer with brine
9. dry with materialdried over Na2SO4
10. customRemoval of the solvent in vacuum
11. waitleft the title compound as white solid (9.00 g, 103%)

ORD record

ord-51c56aceecb74afea22b3836069578dc

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08183262B2