Lithium tri-s-butylborohydride → HCID 59278476, compound

To a chilled (−78° C.) solution of 2-methyl-propane-2-sulfinic acid [(S)-1-(4-bromo-pyridin-2-yl)-propyl]-amide (985 mg, 3.10 mmol) in THF (25 mL) was added a 1 M solution of L-Selectride (3.2 mL, 3.2 mmol) in THF. The reaction was monitored by TLC (ethyl acetate-ether 3:7) indicating a single diastereomer when compared to a mixture of diastereomers prepared by reduction of 2-methyl-propane-2-sulfinic acid [(S)-1-(4-bromo-pyridin-2-yl)-propyl]-amide with lithium borohydride in THF. 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 by silica gel chromatography eluting with a gradient of 0-100% ethyl acetate in dichloromethane. The material from the column was crystallized from hexanes to afford (S)-1-(4-bromo-pyridin-2-yl)-propylamine.

1. additioncompared to a mixture of diastereomers
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 by silica gel chromatography
9. washeluting with a gradient of 0-100% ethyl acetate in dichloromethane
10. customThe material from the column was crystallized from hexanes

ORD record

ord-d9ce1576f18d4a7c9d2b644b20b3a1da

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08063065B2