Trimethyl borate → (2-Bromo-6-methoxyquinolin-3-yl)boronic acid

温度

0 °C

n-BuLi (1.6 N in hexanes, 14.4 mL, 23.0 mmol) was added at −78° C. to a solution of 2,2,6,6-tetramethylpiperidine (3.11 g, 22.05 mmol) in anhydrous THF (59 mL), and the mixture was then warmed to 0° C. for 0.5 h. The mixture was cooled back to −78° C. and treated with a solution of 2-bromo-6-methoxyquinoline (4.57 g, 19.17 mmol) in THF (14 mL). After stirring for 1 h, a solution of trimethyl borate (2.46 mL, 22.05 mmol) in THF (14 mL) was added, and the mixture was maintained at −78° C. for a further 2 h. A mixture of THF (14 mL) and H2O (3.5 mL), were added then the solution was warmed to −10° C. and treated with water (70 mL) and Et2O (70 mL). Aqueous NaOH (1 N, 75 mL) was added, and the aqueous layer was separated and acidified to pH 4 with aqueous HCl (3 N). The aqueous phase was extracted with Et2O, and the combined extracts were washed with brine and dried over Na2SO4. Filtration and removal of the volatiles afforded the title compound (4.64 g, 86% yield) as an oily solid that was used directly in the subsequent step. LCMS (ES+) m/z 282, 284 (M+H)+.

1. temperatureThe mixture was cooled back to −78° C.
2. temperaturethe mixture was maintained at −78° C. for a further 2 h
3. additionwere added
4. temperaturethe solution was warmed to −10° C.
5. customthe aqueous layer was separated
6. extractionThe aqueous phase was extracted with Et2O
7. washthe combined extracts were washed with brine
8. dry with materialdried over Na2SO4
9. filtrationFiltration and removal of the volatiles

ORDレコード

ord-4addfeb457ee48fdad50d7f7ea036591

出典データセット

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08591878B2