Reaktion #95694

Reaktionsgleichung

ethyl α-amino-1,3,4,5-tetrahydro-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetate

ethyl acetate

N,N-dimethylformamide diethyl acetal

→

ethyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturunder reflux for 0.5 hour
3. 3
   TemperaturAfter cooling
4. 4
   Filtrationthe separated material is filtered off under suction
5. 5
   Sonstigerecrystallised
6. 6
   Sonstigeform ethanol

Vorschrift

4.1 g of ethyl α-amino-1,3,4,5-tetrahydro-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetate are dissolved in 25 ml of ethyl acetate, treated with 3.1 ml (18.1 mmol) of N,N-dimethylformamide diethyl acetal and heated to boiling under reflux for 0.5 hour. After cooling, the separated material is filtered off under suction and recrystallised form ethanol. After chromatography of the mother liquor, there is obtained a second portion of ethyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of the same purity; melting point 166°-168° C.

Quelle