Trifluoroacetic acid → HCID 69018507, compound

Temperature

0 °C

Add molecular sieves (3 Å, 12.0 g), (S)-(−)-α-methylbenzylamine (6.4 mL, 50.0 mmol) to a solution of ethylglyoxalate (10.3 mL, 50.0 mmol) in dichloromethane (200 mL) cooled in an ice bath. Stir the mixture at 0° C. for 2 h, and then cool to −78° C. Add trifluoroacetic acid (4.10 mL, 55.0 mmol), boron trifluoride etherate (6.90 mL, 55.0 mmol), and 5-methoxymethyl-1,3-cyclopentadiene (60.0 mmol, prepared in situ by adding cyclopentadienylsodium (2.0 M in THF, 30.0 mL, 60.0 mmol) to a solution of chloromethyl methyl ether (5.70 mL, 75.0 mmol) in tetrahydrofuran (30 mL) at −55° C.) with a 5 min interval between each addition. Stir for 2 h at −78° C. and refrigerate (−20° C.) overnight. Quench the reaction with saturated aqueous sodium bicarbonate solution (200 mL) and stir the mixture vigorously for 15 min. Separate the layers, dry the organic layer (magnesium sulfate), concentrate, and purify (silica gel chromatography 10:90 to 30:70 ethyl acetate:hexanes) to give the title compound (3.95 g, 25%).

1. temperaturecooled in an ice bath
2. temperaturecool to −78° C
3. additionbetween each addition
4. stirringStir for 2 h at −78° C.
5. customrefrigerate (−20° C.) overnight
6. customQuench
7. customthe reaction with saturated aqueous sodium bicarbonate solution (200 mL)
8. stirringstir the mixture vigorously for 15 min
9. customSeparate the layers
10. dry with materialdry the organic layer (magnesium sulfate)
11. concentrationconcentrate
12. custompurify (silica gel chromatography 10:90 to 30:70 ethyl acetate:hexanes)

ORD record

ord-c4c69a0d9d3344e087f38984250ab016

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07618978B2