Water → HCID 22954295, compound

Temperature

0 °C

A solution of sodium nitrite (5.1 g, 73 mmol) in water (15 ml) was added drop-wise at 0° C. over 5 hours to a stirred mixture of L-leucine (8.75 g, 67 mmol), potassium bromide (29.75 g, 0.25 mol) and concentrated sulphuric acid (8.6 ml) in water (100 ml). The mixture was stirred for 30 minutes at 0° C. then at ambient temperature for 20 hours. The product was extracted into diethyl ether (2×150 ml) then the combined ethereal layers were washed with saturated aqueous sodium chloride solution (2×100 ml), dried (MgSO4) and the solvent removed in vacuo. The residue was purified by flash chromatography over silica gel eluting with a gradient of methanol:dichloromethane 1:50→1:20. Appropriate fractions were combined and the solvents removed in vacuo to leave (S)-2-bromomethylpentanoic acid as a colourless oil (2.22 g, 17%). TLC (single spot, Rf=0.2, methanol:dichloromethane 1:20).

1. waitat ambient temperature for 20 hours
2. extractionThe product was extracted into diethyl ether (2×150 ml)
3. washthe combined ethereal layers were washed with saturated aqueous sodium chloride solution (2×100 ml)
4. dry with materialdried (MgSO4)
5. customthe solvent removed in vacuo
6. customThe residue was purified by flash chromatography over silica gel eluting with a gradient of methanol:dichloromethane 1:50→1:20
7. customthe solvents removed in vacuo

ORD record

ord-ea331fa054374151be74265ff0ff2152

Source dataset

uspto-grants-2006_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07132449B2