Reaktion #79504

Reaktionsgleichung

POCl3

methyl 2-oxobutanoate

toluene

2-pyrrolidinone

→

product

Ausbeute 60.0%

Methyl (Z)-2-(2-oxotetrahydro-1H-1-pyrrolyl)-2-butenoate

Ausbeute 60.0%

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 100 ml flask fitted with a magnetic stirring bar
2. 2
   TemperaturAfter cooling down the solution
3. 3
   Waschenwas washed with 10% aq KHSO4 (2×3 vol)
4. 4
   Extraktionback extracted with toluene (1×6 vol)
5. 5
   TrocknenThe combined organic phase was dried over MgSO4
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated in vacuo
8. 8
   Sonstigeto afford crude material (7.5 g) as an orange mobile oil
9. 9
   workup.DISTILLATIONThe crude oil was distilled (92-94° C., 0.1 mm Hg)

Vorschrift

A 100 ml flask fitted with a magnetic stirring bar and a Dean-Stark trap was charged with methyl 2-oxobutanoate (7.5 g, 73 mmol), toluene (50 ml, 7 vol) and 2-pyrrolidinone (8.4 ml, 111 mmol, 1.5 equiv) followed by dropwise addition of POCl3 (1.6 ml, 20 mmol, 0.27 equiv). The reaction mixture was stirred under reflux with azeotropic removal of water via the Dean-Stask trap for 8 hours. After cooling down the solution was washed with 10% aq KHSO4 (2×3 vol). The aqueous phase was saturated with NaCl and back extracted with toluene (1×6 vol). The combined organic phase was dried over MgSO4, filtered and concentrated in vacuo to afford crude material (7.5 g) as an orange mobile oil. The crude oil was distilled (92-94° C., 0.1 mm Hg) and gave pure product (4.7 g, 60%) as a colourless oil.

Quelle