Reaction #59632

Reaction equation

diethyl oxalate

n-butyl-lithium

1-bromo-2-methoxybenzene

NH4Cl

→

expected product

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

Solvents

pentane

ether

Conditions

Workup

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

Procedure

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.

Source