Tetrahydrofuran → 2-Ethyl-N-(furan-2-yl)butanamide

Temperature

-10 °C

The tert-butylcarbamate from Example 1 (27.5 g, 0.15 mole) was dissolved in dry tetrahydrofuran (75 ml) and added dropwise at 0°-5° C. to a suspension of sodium hydride (50% oil dispersion, 7.2 g, ≡0.15 mole) in dry tetrahydrofuran (75 ml). When gassing was complete, the mixture was cooled to -10° C. and diethylacetylchloride (20 g, 0.15 mole) in dry tetrahydrofuran (30 ml) added dropwise. The temperature was allowed to come to room temperature over a period of 11/4 hours and the light brown solution poured onto ice/water. After extraction at pH 7 with dichloromethane, the organic solvent phase was evaporated (rotary) to give a light brown oil which was dissolved in methyl ethyl ketone (150 ml) and gently refluxed, on a steam bath, with anhydrous lithium iodide (20 g, 0.15 mole) for 21/2-3 hours. The brown solution was evaporated (rotary) to remove methyl ethyl ketone, then poured into water and extracted with benzene at pH 2. The benzene extract was washed successively with saturated potassium bicarbonate solution, then water and evaporated (rotary) to give a light brown crystalline solid which was recrystallised from benzene/petroleum ether 60/80° C. to yield 2-(2'-ethylbutanamido)furan (19.6 g) m.p. 100° C.

1. additionthe light brown solution poured onto ice/water
2. extractionAfter extraction at pH 7 with dichloromethane
3. customthe organic solvent phase was evaporated (rotary)
4. customto give a light brown oil which
5. customThe brown solution was evaporated (rotary)
6. customto remove methyl ethyl ketone
7. additionpoured into water
8. extractionextracted with benzene at pH 2
9. extractionThe benzene extract
10. washwas washed successively with saturated potassium bicarbonate solution
11. customwater and evaporated (rotary)
12. customto give a light brown crystalline solid which
13. customwas recrystallised from benzene/petroleum ether 60/80° C.

ORD record

ord-a3b4e40b0d9b40e4a4e253f83a16e1fd

Source dataset

uspto-grants-1980_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04222946