Pyridine → 2-Bromoethyl 2,2-dimethylpropanoate

To a solution of 2-bromoethanol (0.36 mL) and pyridine (0.61 mL) in tetrahydrofuran (5 mL) was added pivaloyl chloride (0.62 mL) under ice-cooling, and the mixture was stirred at room temperature overnight. The reaction mixture was poured into a saturated aqueous ammonium chloride solution, and the resulting mixture was extracted with diethyl ether. The extract was washed with water, a saturated aqueous sodium hydrogen carbonate solution and brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure to give (2-bromoethyl) pivalate (1.04 g). A mixture of 4-bromo-3-(2,3,4,6-tetra-O-pivaloyl-β-D-glucopyranosyloxy)-1H-indazole (0.93 g), (2-bromoethyl)pivalate (0.82 g), cesium carbonate (1.27 g) and sodium iodide (0.2 g) in N,N-dimethylformamide (10 mL) was stirred at 65° C. for 6 hours. The reaction mixture was poured into water, and the resulting mixture was extracted with diethyl ether. The extract was washed with water and brine, and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, and the residue was purified by column chromatography on silica gel (eluent: n-hexane/ethyl acetate=4/1−3/1) to give the title compound (0.73 g).

1. temperaturecooling
2. extractionthe resulting mixture was extracted with diethyl ether
3. washThe extract was washed with water
4. dry with materiala saturated aqueous sodium hydrogen carbonate solution and brine, and dried over anhydrous sodium sulfate
5. customThe solvent was removed under reduced pressure

ORD record

ord-ca0cf925423b445d8aea51a7095a6f41

Source dataset

uspto-grants-2008_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07375113B2