Tetrahydrofuran → HCID 69731349, compound

Temperature

0 °C

[2-(4-Bromo-2-methoxy-5-methyl-phenoxymethoxy)-ethyl]-trimethyl-silane (2.6 g, 7.5 mmol) was stirred in dry THF (10 mL) at −78° C. under argon. n-Butyllithium (3.75 mL, 2.5 M in hexanes, 9.36 mmol) was added dropwise, and the reaction stirred for 30 min before it was transferred via cannula to a flask of trimethyl borate (8.4 mL, 75 mmol) in THF (15 mL), which was also stirring at −78° C. under argon. After addition was complete, the reaction stirred 30 min at −78° C. and then 30 min while warming to 0° C. It was then quenched with H2O (20 mL), acidified with 0.1 N HCl, and extracted with ethyl acetate (2×25 mL). Organics were washed with brine (20 mL), dried (Na2SO4), and concentrated in vacuo. Purification by silica gel chromatography (20% to 50% ethyl acetate/hexanes) gave 1.11 g (47%) of 5-methoxy-2-methyl-1-[2-(trimethyl-silanyl)-ethoxymethoxy]-phenyl-boronic acid as a white solid. 1H NMR (300 MHz, CDCl3) δ 7.78 (s, 1H), 7.10 (s, 1H), 5.36 (s, 2H), 3.93 (s, 3H), 3.83 (t, 2H, J=8.4 Hz), 2.79 (s, 3H), 0.98 (t, 2H, J=8.4 Hz), 0.01 (s, 9H). Anal. (C14H25BO5Si—H2O) C, H. Calculated: C, 57.15; H, 7.88. Found: C, 56.89; H, 7.87.

1. stirringwas also stirring at −78° C. under argon
2. additionAfter addition
3. stirringthe reaction stirred 30 min at −78° C.
4. customIt was then quenched with H2O (20 mL)
5. extractionextracted with ethyl acetate (2×25 mL)
6. washOrganics were washed with brine (20 mL)
7. dry with materialdried (Na2SO4)
8. concentrationconcentrated in vacuo
9. customPurification by silica gel chromatography (20% to 50% ethyl acetate/hexanes)

ORD record

ord-76aa6b7b7e614299818676e86cbd6d47

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06891044B2