Sodium hydride → 2,3-Dihydrofuro[3,2-b]pyridine

To a suspension of 60% sodium hydride (11.4 g, 286 mmol) in DMSO (170 mL) was added trimethylsulfonium iodide (29.9 g, 136 mmol), and the mixture was stirred at room temperature for 30 min. A solution of (3-hydroxypyridin-2-yl)-N,N,N-trimethylmethanaminium iodide (40.0 g, 136 mmol) in DMSO (130 mL) was added dropwise thereto, and the mixture was further stirred at room temperature for 2 hr. The reaction mixture was diluted with water, and the mixture was extracted with ethyl acetate. 1M Hydrochloric acid was added to the extract, and the mixture was extracted with water. The extract was basified with 1M aqueous sodium hydroxide solution and extracted again with ethyl acetate. The extract was washed with saturated brine and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=20/80→50/50) to give the title compound (7.77 g, yield 47%).

1. stirringthe mixture was further stirred at room temperature for 2 hr
2. extractionthe mixture was extracted with ethyl acetate
3. addition1M Hydrochloric acid was added to the extract
4. extractionthe mixture was extracted with water
5. extractionextracted again with ethyl acetate
6. washThe extract was washed with saturated brine
7. dry with materialdried over anhydrous sodium sulfate
8. customThe solvent was evaporated under reduced pressure
9. customthe residue was purified by silica gel column chromatography (ethyl acetate/hexane=20/80→50/50)

ORD record

ord-f8d74b6890514064a4aed87fe144c1c0

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08273761B2