反应详情

A solution of methyl 3,5-dimethylbenzoate (50 g; 300 mmol) in DME (80 ml) was added to a suspension of NaH (26.8 g; 60% in oil; 670 mmol) in DME (80 ml) under argon. The mixture was heated to reflux and a solution of methyl acetate (45 g; 610 mmol) in DME (40 ml) added dropwise. The mixture was heated for a further 4 h under reflux. The mixture was cooled and the excess of NaH destroyed by the dropwise addition of MeOH (40 ml). The mixture was poured into dilute HCl (2N), extracted with Et2O and the organic phase was washed with water, brine and dried over MgSO4. The residue was purified by flash chromatography eluting with Et2O/hexanes (10% Et2O) to give methyl 4-(3′,5′-dimethylphenyl)acetoacetate as a yellow oil (31 g).

1. temperatureThe mixture was heated
2. temperatureto reflux
3. temperatureThe mixture was heated for a further 4 h
4. temperatureunder reflux
5. temperatureThe mixture was cooled
6. customthe excess of NaH destroyed by the dropwise addition of MeOH (40 ml)
7. additionThe mixture was poured into dilute HCl (2N)
8. extractionextracted with Et2O
9. washthe organic phase was washed with water, brine
10. dry with materialdried over MgSO4
11. customThe residue was purified by flash chromatography
12. washeluting with Et2O/hexanes (10% Et2O)