Cesium carbonate → HCID 54429101, compound

The title compound was prepared by reacting 14.652 g of (S)-2-hydroxy-3-methylbutyric acid with 21.21 g cesium carbonate and 20.396 of para-methoxybenzyl chloride in 300 mL of DMF at room temperature for 40 hours. The reaction mixture was poured into 400 mL of ice water, extracted with 5×150 mL ether, and the combined ether solution was washed with 5×100 mL water and 100 mL saturated brine. After drying over Na2SO4 and filtration, the filtrate was concentrated under reduced pressure to give 30.62 g of crude product, which was purified by flash chromatography on silica gel with 10˜30% ethyl acetate in hexanes to afford 29.12 g title compound as a colorless oil (99%). RF: 0.58 (30% EtOAc in hexane). 1H NMR (500 MHz, CDCl3): δ7.30˜7.33 (m, 2H), 6.90˜6.93 (m, 2H), 5.20 (AB d, 11.9 Hz, 1H), 5.15 (AB d, 11.9 Hz, 1H), 4.07 (d, 3.4 Hz, 1H), 3.83 (s, 3H), 2.68 (br s, 1H), 2.04˜2.13 (m, 1H), 1.01 (d, 7.0 Hz, 3H), 0.83 (d, 6.9 Hz, 3H).

1. customat room temperature
2. customfor 40 hours
3. extractionextracted with 5×150 mL ether
4. washthe combined ether solution was washed with 5×100 mL water and 100 mL saturated brine
5. dry with materialAfter drying over Na2SO4 and filtration
6. concentrationthe filtrate was concentrated under reduced pressure
7. customto give 30.62 g of crude product, which

ORD record

ord-1621003477144a27ac0e6c2fb8db8459

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06248755B1