Reaktion #216386

Reaktionsgleichung

HCl

Dimethyl oxalate

sodium methoxide

methanol

4'-chloroacetophenone

→

yellow solid

Ausbeute 95.0%

methyl-4-[4-(chloro)phenyl]-2,4-dioxobutanoate

Ausbeute 95.0%

Lösungsmittel

ethyl acetate

diethyl ether

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONadded to the reaction dropwise over 3 minutes
2. 2
   workup.ADDITIONwere added
3. 3
   SonstigeThe organic layer was collected
4. 4
   Waschenwashed with brine (350 mL)
5. 5
   Trocknendried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated in vacuo

Vorschrift

Dimethyl oxalate (23.6 g, 200 mmol) was placed in a 500 mL three-necked round bottom flask, and dissolved in diethyl ether (200 mL). To the stirred solution was added 25 weight % sodium methoxide in methanol (48 mL, 210 mmol) via an addition funnel over a 2 minute period. Next, 4'-chloroacetophenone (25.94 g, 200 mmol) was dissolved in diethyl ether (50 mL), and added to the reaction dropwise over 3 minutes. After stirring overnight (18 hours), 1N HCl (400 mL) and ethyl acetate (750 mL) were added. The organic layer was collected, washed with brine (350 mL), dried over MgSO4, filtered, and concentrated in vacuo to give 45.7 g of a yellow solid. The solid was recrystallized from ethyl acetate and iso-octane to give 23 g, 48% of the dione, mp 108.5°-110.5° C.

Quelle