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 pH7 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 poued into water and extracted with benzene at pH2. 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 pH7 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. extractionextracted with benzene at pH2
8. extractionThe benzene extract
9. washwas washed successively with saturated potassium bicarbonate solution
10. customwater and evaporated (rotary)
11. customto give a light brown crystalline solid which
12. customwas recrystallised from benzene/petroleum ether 60°/80° C.

ORD record

ord-569d998a371541509d81e445482c6368

Source dataset

uspto-grants-1980_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04187232