反应详情

Diethyl oxalate (4.4 g, 30.2 mmol) was dissolved in dry ethyl ether (30 mL) and freshly distilled THF (30 mL) and cooled to −78° C. with stirring, under a nitrogen atmosphere. Then added 3-chlorophenylmagnesium bromide (0.5 M in THF, 72.5 mL, 36.2 mmol) dropwise, via an addition funnel, while keeping the temperature between −75 to −78° C. The addition took approximately 90 minutes. After 3 hours, the reaction was quenched by the dropwise addition of 2N sulfuric acid (50 mL, 91 mmol) at −78° C. and upon completion of the addition, the mixture was allowed to return to room temperature. The mixture was extracted with ethyl ether (3×) and the combined ether extracts were washed with brine (2×), dried over magnesium sulfate, filtered, evaporated in vacuo and vacuum-dried to yield ethyl-(3-chlorophenyl)(oxo)acetate (6.5 g, HPLC RT=3.46 min, Method A; LCMS m/z=213).

1. custombetween −75 to −78° C
2. additionThe addition
3. waitAfter 3 hours
4. customto return to room temperature
5. extractionThe mixture was extracted with ethyl ether (3×)
6. washthe combined ether extracts were washed with brine (2×)
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. customevaporated in vacuo
10. customvacuum-dried