L-tert-Leucine → (2S)-2-hydroxy-3,3-dimethylbutanoic acid

To a solution of 30.0 g (0.229 mol) of L-tert-leucine in 345 mL of 1 N sulfuric acid, cooled to 0° C., was added over 2 h a solution of 23.7 g (0.343 mol) of sodium nitrite in 83 mL of water. The temperature was maintained below 5° C. during the addition, and the mixture was then refrigerated for 24 h. The solution was then extracted with 150 mL of ether (3×) and the extract was washed with 100 mL of saturated aqueous sodium chloride. The extract was dried over anhydrous magnesium sulfate, filtered, and concentrated to afford 19.5 g (65%) of a pale yellow oil. The crude product was taken to the next step. 1H-NMR (300 MHz, CDCl3): δ 3.91 (s, 1H), 1.01 (s, 9H).

1. temperatureThe temperature was maintained below 5° C. during the addition
2. extractionThe solution was then extracted with 150 mL of ether (3×)
3. washthe extract was washed with 100 mL of saturated aqueous sodium chloride
4. dry with materialThe extract was dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated

ORD record

ord-acd1a906e9dd46528a445c6da9fd6d1d

Source dataset

uspto-grants-2007_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07288541B2