Chlorotrimethylsilane → tert-butyl 2-(1-hydroxy-4-methyl-6-(tetrahydro-2H-pyran-2-yloxy)-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate

Temperatur

55 °C

To a suspension of zinc powder (2.81 g, 43.35 mmol) in dry THF was added TMSCl (0.94 g, 8.67 mmol) at 40° C. The mixture was stirred at 55° C. for 15 min. The mixture was allowed to cooled to 30° C. and tert-butyl 2-bromoacetate (6.76 g, 34.68 mmol) was added slowly to the reaction mixture between 37-40° C. After completion of addition, the resulting mixture was stirred at room temperature for an additional 30 min. To a solution of 2-methyl-4-(tetrahydro-2H-pyran-2-yloxy)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzaldehyde (3 g, 8.67 mmol) in 20 mL dry THF at −78° C. was added dropwise the above prepared reaction mixture. The reaction mixture was stirred at room temperature for 1 h and quenched by ice-water at 0° C. The mixture was extracted with EtOAc (3×15 mL). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was purified by silica gel column (EA:PE=1:10) to give 2.2 g of desired product as a light yellow oil.

1. temperatureto cooled to 30° C.
2. additionAfter completion of addition
3. stirringthe resulting mixture was stirred at room temperature for an additional 30 min
4. customabove prepared
5. customreaction mixture
6. stirringThe reaction mixture was stirred at room temperature for 1 h
7. customquenched by ice-water at 0° C
8. extractionThe mixture was extracted with EtOAc (3×15 mL)
9. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
10. concentrationconcentrated in vacuo
11. customThe residue was purified by silica gel column (EA:PE=1:10)

ORD-Eintrag

ord-c2bf9b58378b462db367975254529f55

Quelldatensatz

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08343944B2