반응 #5118

반응 방정식

diethyl malonate

sodium

3,4-dimethylbenzyl chloride

→

3-(3,4-dimethylphenyl)propanoic acid

수율 55.0%

용매

ethanol

ethyl ether

반응 조건

후처리

1. 1
   workup.STIRRINGThis reaction mixture was stirred for 1 hour at room temperature
2. 2
   온도heated at the boiling temperature for 4 hours
3. 3
   농축concentrated under reduced pressure
4. 4
   기타to produce residues, which
5. 5
   세척This ethereal solution was washed with water
6. 6
   기타To the residues obtained
7. 7
   농축after a further concentration of the organic phase
8. 8
   workup.ADDITIONwere added 500 ml of water and 170 g of KOH
9. 9
   온도and this mixture was heated at the boiling temperature for 24 hours
10. 10
    농축This 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
    온도The resultant solution was heated at the boiling temperature for 24 hours
13. 13
    추출extracted twice with 300 ml of ethyl ether
14. 14
    기타evaporated under reduced pressure
15. 15
    기타to obtain solids, which
16. 16
    기타were recrystallized

실험 절차

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).

출처