Carbon Dioxide → 5-Ethylfuran-2-carboxylic acid

Temperature

-70 °C

2-Ethylfuran (9.1 g) was dissolved in diethyl ether, and the mixture was cooled to -70° C. under nitrogen atmosphere. n-Butyllithium (1.6M in hexane, 60 ml) was slowly added dropwise. The mixture was stirred at room temperature for 2 hours, and then cooled to -70° C. The mixture was stirred for 30 minutes with introducing carbon dioxide gas, and then warmed to room temperature. The mixture was stirred at room temperature for 30 minutes, poured into ice-water, acidified with concentrated hydrochloric acid and extracted with diethyl ether. The extract was washed with saturated aqueous sodium chloride and concentrated under reduced pressure. The residue was crystallized from water and collected by filtration to give 5-ethyl-2-furancarboxylic acid (9.0 g).

1. temperaturecooled to -70° C
2. temperaturewarmed to room temperature
3. stirringThe mixture was stirred at room temperature for 30 minutes
4. extractionextracted with diethyl ether
5. washThe extract was washed with saturated aqueous sodium chloride
6. concentrationconcentrated under reduced pressure
7. customThe residue was crystallized from water
8. filtrationcollected by filtration

ORD record

ord-e00fc9bcc5b445959acaa706c66bdc95

Source dataset

uspto-grants-1998_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05840917