Sulfuric Acid → 3-(3,5-Difluorophenoxy)propanoic acid

At about −20° C., 17.22 g (172.18 mmol) of chromium(VI) oxide were taken up in 1.2 l of acetone and 38 ml of water, and 19 ml of conc. sulfuric acid were slowly added to the mixture. The mixture was stirred for 10 min and then 8.10 g (43.05 mmol) of the compound from Example 168A in 400 ml of acetone were added dropwise over the course of 1 h. The mixture was stirred at 0° C. for 1.5 h. After addition of 90 ml of propan-2-ol, the reaction mixture was filtered through kieselguhr, the solvents were removed from the filtrate in vacuo, and the residue was taken up in 500 ml of diethyl ether. The solution was washed twice with saturated aqueous sodium chloride solution and dried over sodium sulfate, and the solvents were removed in vacuo. 11.36 g of the title compound were obtained and were reacted further in the next stage without further purification.

1. customAt about −20° C.
2. stirringThe mixture was stirred at 0° C. for 1.5 h
3. filtrationthe reaction mixture was filtered through kieselguhr
4. customthe solvents were removed from the filtrate in vacuo
5. washThe solution was washed twice with saturated aqueous sodium chloride solution
6. dry with materialdried over sodium sulfate
7. customthe solvents were removed in vacuo

ORD record

ord-77e405b68e054559a3d2979c9f126b3a

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08063234B2