1-Cyclohexenyl trifluoromethanesulfonate → 4-Cyclohex-1-en-1-yl-benzoic acid ethyl ester

Cyclohexen-1-yl trifluoromethanesulfonate (1.00 g, 4.34 mmol), lithium chloride (0.551 g, 13.0 mmol) and tris-dibenzylideneacetone di-palladium (0) (79.5 mg, 0.0868 mmol) were combined in anhydrous N-methylpyrrolidinone (20 mL) and the resulting solution deoxygenated by sparging with nitrogen for 30 minutes. To the catalyst solution was added a solution of 4-(tri-n-butyl-stannyl)-benzoic acid ethyl ester of Step A (2.10 g, 4.77 mmol) in anhydrous N-methylpyrrolidinone (9 mL). The reaction was stirred at room temperature for 38 hours, followed by addition of 1 M potassium fluoride (5 mL). After stirring for 3 hours, the reaction mixture was diluted with ethyl acetate (200 mL) and filtered through celite. The filtrate was washed with 1 M potassium fluoride, water and brine. The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by flash column chromatography on silica gel, eluting with a solvent gradient of from 0 to 10% ethyl acetate in hexane. A solid was isolated which was recrystallized from pentane (−20° C.) to afford the title compound (0.608 g) as a white solid, m.p. 66° C.

1. customthe resulting solution deoxygenated
2. customby sparging with nitrogen for 30 minutes
3. stirringAfter stirring for 3 hours
4. filtrationfiltered through celite
5. washThe filtrate was washed with 1 M potassium fluoride, water and brine
6. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by flash column chromatography on silica gel
10. washeluting with a solvent gradient of from 0 to 10% ethyl acetate in hexane
11. customA solid was isolated which
12. customwas recrystallized from pentane (−20° C.)

ORD record

ord-65bc4c8b04214cb1be443f6d04d9a673

Source dataset

uspto-grants-2006_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07022699B2