反应详情

温度

-65 °C

Dimethyl oxalate (5.90 g, 50 mmol) was dissolved in THF (50 mL) and ether (50 mL) in a 3-neck round bottom flask fitted with a mechanical stirrer. The solution was stirred vigorously at −65° C. as a 1.0 M THF solution of 4-fluorophenylmagnesium bromide (60 mL, 60 mmol) was added dropwise over 40 min. The mixture was stirred 30 min at −65° C. and allowed to warm to −20° C. over 30 min before being poured into 2N aq. HCl (50 mL) with stirring. The layers were separated and the aq. layer was extracted with ether (3×50 mL). The combined organic layers were washed with saturated aq. brine (2×50 mL), dried (sodium sulfate), decanted, and evaporated. The residue was dissolved in ethyl acetate, dried (sodium sulfate), filtered, and evaporated to give a yellow solid. The crude product was dissolved in warm hexane (25 mL), filtered, and cooled to −20° C. Filtration followed by washing with cold hexane (15 mL) gave 4.95 g of the title compound as light tan crystals.

1. additionwas added dropwise over 40 min
2. temperatureto warm to −20° C. over 30 min
3. stirringwith stirring
4. customThe layers were separated
5. extractionthe aq. layer was extracted with ether (3×50 mL)
6. washThe combined organic layers were washed with saturated aq. brine (2×50 mL)
7. dry with materialdried (sodium sulfate)
8. customdecanted
9. customevaporated
10. dissolutionThe residue was dissolved in ethyl acetate
11. dry with materialdried (sodium sulfate)
12. filtrationfiltered
13. customevaporated
14. customto give a yellow solid
15. filtrationfiltered
16. temperaturecooled to −20° C
17. filtrationFiltration
18. washby washing with cold hexane (15 mL)