Borane;tetrahydrofuran → (R)-2-Bromo-1-(2,2-dimethyl4H-benzo[1,3]dioxin-6-yl)ethanol

To the product of step (c) (10 g, 35.1 mmol) in 100 mL of THF was added the solid catalyst of Preparation 13, step (c)(1) (0.97 g, 3.5 mmol). The solution was cooled to between 20° C. and 10° C. and BH3-THF (35 mL, 35 mmol) diluted with 50 mL THF was added dropwise via a dropping funnel. After the addition was complete, the reaction mixture was allowed to warm to ambient temperature. After 30 minutes, the reaction mixture was quenched by slow addition of 50 mL of methanol and then concentrated to a thick oil. The oil was purified by silica gel chromatography eluted with 1:2 ethyl acetate/hexanes. The fractions were combined and concentrated to give the title compound as an off-white solid.

1. customthe solid catalyst of Preparation 13, step (c)(1) (0.97 g, 3.5 mmol)
2. temperatureThe solution was cooled to between 20° C. and 10° C.
3. additionwas added dropwise via a dropping funnel
4. additionAfter the addition
5. customthe reaction mixture was quenched by slow addition of 50 mL of methanol
6. concentrationconcentrated to a thick oil
7. customThe oil was purified by silica gel chromatography
8. washeluted with 1:2 ethyl acetate/hexanes
9. concentrationconcentrated

ORD record

ord-34d2ae0f7dad4117b09e2a813d2f475e

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08618131B2