2-Phenylfuran → 4,4,5,5-Tetramethyl-2-(5-phenylfuran-2-yl)-1,3,2-dioxaborolane

Temperature

-78 °C

To a solution of 2-phenylfuran (1.20 g, 8.32 mmol) in dry tetrahydrofuran (100 mL) was added a solution of n-BuLi (4.9 mL, 2.5 M solution in hexane) dropwise with stirring at −78° C. under nitrogen. The resulting solution was warmed slowly to −40° C. during 45 min and stirred at this temperature for another 30 min. The mixture was cooled again below −78° C. followed by dropwise addition of 4,4,5,5-tetramethyl-2-(propan-2-yloxy)-1,3,2-dioxaborolane (3.10 g, 16.66 mmol). After warming to room temperature, the mixture was quenched with NH4Cl (aq) and extracted with ethyl acetate (3×80 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give the residue, which was purified by silica gel column chromatography (2% ethyl acetate in petroleum ether) to afford 4,4,5,5-tetramethyl-2-(5-phenylfuran-2-yl)-1,3,2-dioxaborolane (560 mg, 25%).

1. temperatureThe resulting solution was warmed slowly to −40° C. during 45 min
2. stirringstirred at this temperature for another 30 min
3. temperatureThe mixture was cooled again below −78° C.
4. temperatureAfter warming to room temperature
5. customthe mixture was quenched with NH4Cl (aq)
6. extractionextracted with ethyl acetate (3×80 mL)
7. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated under reduced pressure
10. customto give the residue, which
11. customwas purified by silica gel column chromatography (2% ethyl acetate in petroleum ether)

ORD record

ord-d00896ee65af4c1c977532e1d4cf6925

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08912188B2