反应详情

108 g (1.1 mol) of potassium acetate and 11.4 g (0.05 mol) of benzyltriethylammonium chloride are suspended in 900 ml of acetonitrile, treated with 50 ml of acetic acid and heated to reflux temperature. Within 31/2 hours there are added dropwise thereto 150.5 g (1 mol) of methyl 4-chloroacetoacetate in 100 ml of acetonitrile and the mixture is subsequently held at reflux temperature for 4 hours. The reaction mixture is washed 3 times with 200 ml of 5% NaH2PO4 solution each time and the aqueous phases are back-extracted with 200 ml of CH2Cl2. The combined organic phases are dried over magnesium sulphate and concentrated on a rotary evaporator. The crude product distils at 76°-85° C./0.6 mbar and gives 106.17 g (61%) of methyl 4-acetoxyacetoacetate.

1. temperatureheated
2. temperatureto reflux temperature
3. additionWithin 31/2 hours there are added dropwise
4. temperatureat reflux temperature for 4 hours
5. washThe reaction mixture is washed 3 times with 200 ml of 5% NaH2PO4 solution each time
6. extractionthe aqueous phases are back-extracted with 200 ml of CH2Cl2
7. dry with materialThe combined organic phases are dried over magnesium sulphate
8. concentrationconcentrated on a rotary evaporator
9. customThe crude product distils at 76°-85° C./0.6 mbar