反応 #2308

反応方程式

methyl bromoacetate

3,5-dichloro-4-hydroxyacetophenone

Sodium hydride

hexane

→

methyl 4-acetyl-2,6-dichlorophenoxyacetate

溶媒

water

DMF

DMF

反応条件

後処理

1. 1
   温度cooling (ice-bath)
2. 2
   workup.STIRRINGStirring
3. 3
   workup.STIRRINGstirring
4. 4
   workup.WAITwas continued for a further 18 hours at ambient temperature
5. 5
   抽出the mixture was extracted twice with ethyl acetate
6. 6
   乾燥the organic phases dried (MgSO4)
7. 7
   ろ過filtered
8. 8
   その他evaporated
9. 9
   その他The residue, after recrystallisation from hexane (250 ml)

実験手順

Sodium hydride (50% w/w dispersion in mineral oil, 1.32 g) was treated under argon with repeated washes of hexane. The oil-free residue was suspended in dry DMF (10 ml) and, with stirring and cooling (ice-bath), a solution of 3,5-dichloro-4-hydroxyacetophenone (5.13 g) in dry DMF (15 ml) was added dropwise. Stirring was continued for 30 minutes when methyl bromoacetate (3.06 ml) was added dropwise and stirring was continued for a further 18 hours at ambient temperature. The reaction mixture was added to water, the mixture was extracted twice with ethyl acetate, the organic phases dried (MgSO4), filtered and then evaporated. The residue, after recrystallisation from hexane (250 ml), gave methyl 4-acetyl-2,6-dichlorophenoxyacetate, 4.25 g, as white crystals: NMR (d6DMSO) δ 8.00 (2H, s), 4.80 (2H, s), 3.73 (3H, s), 2.59 (3H, s).

出典