Tetrahydrofuran → 4-Ethyl-5,5-bis(4-fluorophenyl)-2,4-pentadienal

Temperature

-40 °C

Butyl lithium (25.7 mL of 2.1M solution, 54 mmol) was added to a solution of N-isopropylcyclohexylamine in 30 mL tetrahydrofuran at -10° C. After stirring for 30 minutes and cooling to -40° C., N-ethylidenecyclohexamine (27 mL of 2M solution, 54 mmol) was added and the solution stirred for 30 minutes. The solution was further cooled to -70° C. and 2-ethyl-3,3-bis(4-fluorophenyl)- 2-propenal(4.9 g, 18 mmol) in 40 mL of tetrahydrofuran was added. The mixture was stirred for 5 hours and quenched with water. The mixture was extracted with diethyl ether, the extracts dried over magnesium sulfate and concentrated in vacuo. The residue was stirred with a mixture of 100 mL of benzene, 40 mL of water and 60 mL of acetic acid for 16 hours and diluted with 1.50 mL of water. The organic layer was separated, washed with saturated sodium bicarbonate solution, dried with magnesium sulfate and concentrated in vacuo. The residue was crystallized from petroleum ether to give 3.45 g of the title compound; m.p. =98°-99.5° C.

1. stirringthe solution stirred for 30 minutes
2. temperatureThe solution was further cooled to -70° C.
3. stirringThe mixture was stirred for 5 hours
4. customquenched with water
5. extractionThe mixture was extracted with diethyl ether
6. dry with materialthe extracts dried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. stirringThe residue was stirred with a mixture of 100 mL of benzene, 40 mL of water and 60 mL of acetic acid for 16 hours
9. additiondiluted with 1.50 mL of water
10. customThe organic layer was separated
11. washwashed with saturated sodium bicarbonate solution
12. dry with materialdried with magnesium sulfate
13. concentrationconcentrated in vacuo
14. customThe residue was crystallized from petroleum ether

ORD record

ord-a7484ae1758648afa9b616e848bfae06

Source dataset

uspto-grants-1991_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05011947