反応 #59632

反応方程式

diethyl oxalate

n-butyl-lithium

1-bromo-2-methoxybenzene

NH4Cl

→

expected product

Ethyl 2-(2-methoxyphenyl)-2-oxoacetate

溶媒

pentane

ether

反応条件

後処理

1. 1
   workup.WAITthe mixture is then left
2. 2
   workup.WAITthe mixture is left
3. 3
   workup.STIRRINGstirring
4. 4
   その他to return to RT
5. 5
   workup.STIRRINGAfter stirring for 1 hour at RT
6. 6
   その他the phases are separated after settling
7. 7
   抽出the aqueous phase is extracted with ether
8. 8
   洗浄the combined organic phases are washed with water
9. 9
   乾燥with saturated NaCl solution and dried over Na2SO4
10. 10
    その他the solvents are evaporated off under vacuum
11. 11
    その他The excess diethyl oxalate is removed by distillation under vacuum (b.p.=87° C. at 2 000 Pa)
12. 12
    その他The resulting product is chromatographed on silica gel
13. 13
    洗浄eluting with a DCM/hexane mixture (50/50; v/v)
14. 14
    その他The product obtained
15. 15
    workup.DISTILLATIONis purified by distillation under vacuum

実験手順

A solution of 27 g of 1-bromo-2-methoxybenzene in 270 ml of ether is cooled to −70° C. under an argon atmosphere, 90 ml of a 1.6 M solution of n-butyl-lithium in pentane are added dropwise and the mixture is then left stirring for 45 minutes. 78 ml of diethyl oxalate are added rapidly and the mixture is left stirring, while allowing the temperature to return to RT. After stirring for 1 hour at RT, saturated NH4Cl solution is added to the mixture, the phases are separated after settling has taken place, the aqueous phase is extracted with ether, the combined organic phases are washed with water and then with saturated NaCl solution and dried over Na2SO4, and the solvents are evaporated off under vacuum. The excess diethyl oxalate is removed by distillation under vacuum (b.p.=87° C. at 2 000 Pa). The resulting product is chromatographed on silica gel, eluting with a DCM/hexane mixture (50/50; v/v) and then with DCM. The product obtained is purified by distillation under vacuum. 13 g of the expected product are obtained; b.p.=110° C. at 3 Pa.

出典