Reaktion #462873

Reaktionsgleichung

2-butyl-4-dimethylaminomethylene-2-imidazolin-5-one

POCl3

sodium hydroxide

→

2-butyl-5-chloroimidazole-4-carbaldehyde

Ausbeute 93.0%

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.DISTILLATIONThen, 1.76 g of POCl3 was distilled off on the Rotavapor
2. 2
   workup.ADDITIONthe residue was treated with 6 ml of ethyl acetate
3. 3
   SonstigeThe mixture thus obtained
4. 4
   ExtraktionThe mixture was extracted twice
5. 5
   TrocknenThe combined organic phases were dried (MgSO4)
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated
8. 8
   Sonstigethe residue was dried in a high vacuum

Vorschrift

A mixture of 1.00 g (5.12 mmol) of 2-butyl-4-dimethylaminomethylene-2-imidazolin-5-one and 3.20 g (20.48 mmol) of POCl3 was heated at 100° C. for 45 minutes. Then, 1.76 g of POCl3 was distilled off on the Rotavapor, and the residue was treated with 6 ml of ethyl acetate. The mixture thus obtained was added to 20 ml of water, and the water was stirred at room temperature for 5 minutes. Then, the pH was adjusted from 0.34 to 7, using 30 percent strength sodium hydroxide solution. The mixture was extracted twice, using 10 ml of ethyl acetate each time. The combined organic phases were dried (MgSO4), filtered and concentrated, and the residue was dried in a high vacuum. 0.89 g of 2-butyl-5-chloroimidazole-4-carbaldehyde was obtained; this product having a purity greater than 95 percent, according to H-NMR. This corresponds to a yield of 93 percent, based on the 2-butyl-4-dimethylaminomethylene-2-imidazolin-5-one.

Quelle