Lithium tri-s-butylborohydride → 2-methyl-propane-2-sulfinic acid[(R)-1-(6-bromo-pyridin-3-yl)-ethyl]-amide

To a chilled (−78° C.) solution of 2-methyl-propane-2-sulfinic acid[1-(6-bromo-pyridin-3-yl)-eth-(E)-ylidene]-amide (1.0 g, 3.30 mmol) in THF (25 mL) was dropwised added lithium tri-sec-butylborohydride solution in THF (L-Selectride, 3.30 mL, 3.30 mmol). The mixture darkened in color upon addition of this reagent. After 3 hours, the mixture was quenched with saturated aqueous ammonium chloride (30 mL) and extracted with ethyl acetate (3×25 mL). The combined organic layers were washed with brine (3×30 mL), dried over magnesium sulfate, filtered and concentrated. The crude material was purified via normal phase flash chromatography on silica gel eluting with ethyl acetate-dichloromethane (0-100%) to afford 2-methyl-propane-2-sulfinic acid[(R)-1-(6-bromo-pyridin-3-yl)-ethyl]-amide (700 mg, 70%) as a slightly yellow solid.

1. additionThe mixture darkened in color upon addition of this reagent
2. customthe mixture was quenched with saturated aqueous ammonium chloride (30 mL)
3. extractionextracted with ethyl acetate (3×25 mL)
4. washThe combined organic layers were washed with brine (3×30 mL)
5. dry with materialdried over magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude material was purified via normal phase flash chromatography on silica gel eluting with ethyl acetate-dichloromethane (0-100%)

ORD record

ord-2df48ee08dd741c3af2de577b603a730

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08575360B2