Potassium Carbonate → Ethyl 2-ethyl-8-methylfuro[3,2-c]pyrazolo[1,5-a]pyridine-1-carboxylate

A mixture of 5-amino-2-methylfuro[3,2-c]pyridin-5-ium 2,4-dinitrobenzenolate (1.44 g, 4.33 mmol), potassium carbonate (838 mg, 6.06 mmol) and ethyl 2-pentynoate (628 μL, 4.76 mmol) in dimethylformamide (20 mL) was stirred at room temperature for 14 hr. The reaction solution was diluted with water, and the mixture was extracted with diethyl ether. The extract was washed with saturated brine, dried over anhydrous sodium sulfate and filtered. The solvent was evaporated under reduced pressure and the residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→30/70) to give the title compound (451 mg, yield 38%).

1. extractionthe mixture was extracted with diethyl ether
2. washThe extract was washed with saturated brine
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. customThe solvent was evaporated under reduced pressure
6. customthe residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→30/70)

ORD record

ord-54a79e1856c544d8b15f19189ea477a7

Source dataset

uspto-grants-2012_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08273761B2