Trimethyl borate → (4-(2-(Pyrrolidin-1-yl)ethoxy)phenyl)boronic acid

温度

-78 °C

To a solution of 1-[2-(4-bromophenoxy)ethyl]-pyrrolidine (2.70 g, 10 mmol) in THF (40 mL) was added n-butyl lithium (6.9 mL 1.6 M in hexanes, 11 mmol) at −78° C. The reaction mixture was stirred at −78° C. for 15 min and then at 0° C. for 15 min. Trimethyl borate (2.5 mL, 22 mmol) was then added to the reaction mixture at 0° C. The mixture was gradually warmed to room temperature overnight. Methyl borate in the reaction mixture was hydrolyzed by reacting with saturated NH4Cl aqueous solution (100 mL) at room temperature for 30 min. The upper organic layer was collected. The aqueous layer was extracted with CHCl3 (2×100 mL). The organic layers were combined, washed with brine (2×100 mL) and dried with MgSO4. The solvent was evaporated, resulting in a dense oil which was purified by column chromatograph (10% MeOH/CHCl3 and 1% Et3N) to yield the product as a white solid.

1. waitat 0° C. for 15 min
2. temperatureThe mixture was gradually warmed to room temperature overnight
3. customThe upper organic layer was collected
4. extractionThe aqueous layer was extracted with CHCl3 (2×100 mL)
5. washwashed with brine (2×100 mL)
6. dry with materialdried with MgSO4
7. customThe solvent was evaporated
8. customresulting in a dense oil which
9. customwas purified by column chromatograph (10% MeOH/CHCl3 and 1% Et3N)

ORDレコード

ord-778b6aa0c17447cd8f5528fdb0a63f95

出典データセット

uspto-grants-2004_11

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US06818646B2