反应 #487502

反应方程式

2-methyl-1,3-cyclopentanedione

methyl iodide

KOH

dioxane

KOH

MeI

dioxane

KOH

MeI

dioxane

→

oil

收率 93.0%

2,2-Dimethyl-cyclopentane-1,3-dione

收率 93.0%

溶剂

water

water

water

反应条件

后处理

1. 1
   其他Synthesized
2. 2
   温度was heated
3. 3
   温度at reflux
4. 4
   温度at reflux
5. 5
   温度heating
6. 6
   温度at reflux
7. 7
   workup.WAITAfter 4 hours
8. 8
   温度the mixture was cooled to room temperature
9. 9
   萃取extracted with ether (1×100 mL, 3×75 mL)
10. 10
    其他The combined ether extracts were evaporated
11. 11
    其他placed in a 120° C.
12. 12
    其他(ca. 15 minutes)
13. 13
    温度The mixture was cooled to room temperature
14. 14
    workup.ADDITIONneutralized by addition of saturated NaHCO3 solution (150 mL)
15. 15
    萃取the resulting mixture extracted with CH2Cl2 (4×75 mL)
16. 16
    干燥The combined CH2Cl2 solution was dried (MgSO4)
17. 17
    过滤filtered
18. 18
    其他evaporated

实验过程

Synthesized according to Agosta and Smith, J. Org. Chem. 35: 3856 (1970) A mixture of 2-methyl-1,3-cyclopentanedione (10.025 g, 89.4 mmol, Aldrich), methyl iodide (6.0 mL, 96.4 mmol, Aldrich), and KOH (5.097 g, 90.8 mmol) in water (25 mL)/dioxane (75 mL) was heated at reflux. After 5 hours, a solution of KOH (2 g) and MeI (2.4 mL) in water (5 mL)/dioxane (15 mL) was added and after another 3 hours at reflux, the solution was stirred at room temperature overnight. A solution of KOH (2 g) and MeI (2.4 mL) in water (5 mL)/dioxane (15 mL) was added to the overnight reaction and heating at reflux. After 4 hours, the mixture was cooled to room temperature and extracted with ether (1×100 mL, 3×75 mL). The combined ether extracts were evaporated, the residue combined with 10% HCl (50 mL), and the resulting mixture placed in a 120° C. oil bath until it began boiling (ca. 15 minutes). The mixture was cooled to room temperature, neutralized by addition of saturated NaHCO3 solution (150 mL) and the resulting mixture extracted with CH2Cl2 (4×75 mL). The combined CH2Cl2 solution was dried (MgSO4), filtered and evaporated to leave a brown oil (10.474 g, 83 mmol, 93%) which was used directly in the next step.

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