Tetrahydrofuran → 5,5-Bis(4-fluorophenyl)-4-(1-methylethyl)-2,4-pentadienal

Temperature

-70 °C

Lithium diisopropylamide (9 mL of 1.8M solution, 15 mmol) was added to N-ethylidenecyclohexanamine (7.5 mL of 2M solution, 15 mmol) in tetrahydrofuran at -40° C. After stirring for 30 minutes and cooling to -70° C., 3,3-bis(4-fluorophenyl)-2-(1-methylethyl)propenal (1.43 g, 5.0 mmol) was added. The reaction was stirred -70° for 1.5 hrs. and quenched with 2N hydrochloric acid. The mixture was extracted with diethyl ether and the extracts concentrated in vacuo. The residue was stirred for 64 hours with a mixture of 50 mL of benzene, 35 mL acetic acid and 15 mL of water. The layers were separated and the aqueous layer extracted with diethyl ether. The combined organic solution was washed with saturated sodium bicarbonate solution, water, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by silica gel chromatography eluting with 1% ethyl acetate in hexane and the material obtained crystallized from hexane to give 0.55 g of the title compound as a yellow solid; m.p. =105°-107° C.

1. stirringThe reaction was stirred -70° for 1.5 hrs
2. customand quenched with 2N hydrochloric acid
3. extractionThe mixture was extracted with diethyl ether
4. concentrationthe extracts concentrated in vacuo
5. stirringThe residue was stirred for 64 hours with a mixture of 50 mL of benzene, 35 mL acetic acid and 15 mL of water
6. customThe layers were separated
7. extractionthe aqueous layer extracted with diethyl ether
8. washThe combined organic solution was washed with saturated sodium bicarbonate solution, water
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated in vacuo
11. customThe residue was purified by silica gel chromatography
12. washeluting with 1% ethyl acetate in hexane
13. customthe material obtained
14. customcrystallized from hexane

ORD record

ord-2ea5b402355e4fbcb51485a53aa79926

Source dataset

uspto-grants-1991_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05011947