Реакция #5118

Уравнение реакции

diethyl malonate

sodium

3,4-dimethylbenzyl chloride

→

3-(3,4-dimethylphenyl)propanoic acid

Выход 55.0%

Растворители

ethanol

ethyl ether

Условия реакции

Обработка

1. 1
   workup.STIRRINGThis reaction mixture was stirred for 1 hour at room temperature
2. 2
   Температураheated at the boiling temperature for 4 hours
3. 3
   Концентрированиеconcentrated under reduced pressure
4. 4
   Другоеto produce residues, which
5. 5
   ПромывкаThis ethereal solution was washed with water
6. 6
   ДругоеTo the residues obtained
7. 7
   Концентрированиеafter a further concentration of the organic phase
8. 8
   workup.ADDITIONwere added 500 ml of water and 170 g of KOH
9. 9
   Температураand this mixture was heated at the boiling temperature for 24 hours
10. 10
    КонцентрированиеThis mixture was concentrated under reduced pressure until about a half of the amount
11. 11
    workup.ADDITION200 ml of sulfuric acid was then slowly added
12. 12
    ТемператураThe resultant solution was heated at the boiling temperature for 24 hours
13. 13
    Экстракцияextracted twice with 300 ml of ethyl ether
14. 14
    Другоеevaporated under reduced pressure
15. 15
    Другоеto obtain solids, which
16. 16
    Другоеwere recrystallized

Методика

To a solution of 70.0 ml of diethyl malonate dissolved in 400 ml of dry ethanol was added 10.0 g of metalic sodium. The reaction mixture was stirred for 30 minutes and cooled to 0° C; and 66.5 g of 3,4-dimethylbenzyl chloride was added thereto. This reaction mixture was stirred for 1 hour at room temperature, heated at the boiling temperature for 4 hours and concentrated under reduced pressure to produce residues, which were dissolved in ethyl ether. This ethereal solution was washed with water. To the residues obtained after a further concentration of the organic phase were added 500 ml of water and 170 g of KOH; and this mixture was heated at the boiling temperature for 24 hours. This mixture was concentrated under reduced pressure until about a half of the amount remained, and 200 ml of sulfuric acid was then slowly added thereto. The resultant solution was heated at the boiling temperature for 24 hours, extracted twice with 300 ml of ethyl ether and evaporated under reduced pressure to obtain solids, which were recrystallized from boiling hexane to provide 42.1 g of 3-(3,4-dimethylphenyl)propanoic acid as a white solid (yield 55%), having the characteristics of: m.p. 82° C.; NMR(CDCl3, 300 MHz) δ2.22(s, 3H, CH3), 2.24(s, 3H, CH3), 2.66(t, J=8 Hz, 2H, ArCH2), 2.89(t, J=8 Hz, 2H, CH2CO), 6.93~7.70(m, 3H, ArH).

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