反应详情

温度

60 °C

In an atmosphere of nitrogen, methyl acetoacetate (480 g, 4.14 mol), calcium hydroxide (80.0 g, 1.08 mol) and toluene (4822 ml) were added to a 10 liter capacity flask, and dehydration/draining was carried out under toluene reflux. After 1 hour, by cooling to 60° C., 4-chlorobutanoic acid chloride (254 g, 1.8 mol) was added dropwise thereto, followed by stirring at 60° C. Further 1 hour thereafter, methanol (1325 g, 41.4 mol) was added thereto, followed by stirring for 6 hours under methanol reflux. After completion of the reaction, the reaction was stopped with 432 ml (2.16 mol) of 5 N hydrochloric acid, and then the organic layer was separated and the organic layer was washed with 5% sodium carbonate aqueous solution and water. After evaporation of the solvent under a reduced pressure using an evaporator, the residue was distilled under a reduced pressure (75 to 85° C./0.1 ton) to obtain crude 6-chloro-3-oxo-hexanoic acid methyl ester (1); 214.9 g (GC purity; δ 0.3%).

1. temperaturereflux
2. stirringby stirring for 6 hours under methanol
3. temperaturereflux
4. customAfter completion of the reaction
5. customthe organic layer was separated
6. washthe organic layer was washed with 5% sodium carbonate aqueous solution and water
7. customAfter evaporation of the solvent under a reduced pressure
8. customan evaporator
9. distillationthe residue was distilled under a reduced pressure (75 to 85° C./0.1 ton)