反应详情

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-butyllithium in pentane are added dropwise and the mixture is then stirred for 45 minutes. 78 ml of diethyl oxalate are added rapidly and the mixture is stirred while allowing the temperature to return to RT. After stirring for 1 hour at RT, saturated NH4Cl solution is added to the reaction mixture, the phases are separated by settling, the aqueous phase is extracted with ether, the combined organic phases are washed with water, 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 2000 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.

1. stirringthe mixture is stirred
2. customto return to RT
3. stirringAfter stirring for 1 hour at RT
4. customthe phases are separated
5. extractionthe aqueous phase is extracted with ether
6. washthe combined organic phases are washed with water, with saturated NaCl solution
7. dry with materialdried over Na2SO4
8. customthe solvents are evaporated off under vacuum
9. customThe excess diethyl oxalate is removed by distillation under vacuum (b.p.=87° C. at 2000 Pa)
10. customThe resulting product is chromatographed on silica gel eluting with a DCM/hexane mixture (50/50; v/v)
11. customThe product obtained
12. distillationis purified by distillation under vacuum