Reaktion #739153

Reaktionsgleichung

acetic acid

ethyl isocyanoacetate

4-methyl-3,4-dihydro-2H-1,4-benzodiazepine-2,5(1H)-dione

diethylchlorophosphate

→

title compound

Ethyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo(1,5-a) (1,4)-benzodiazepine-3-carboxylate

Lösungsmittel

water

DMF

dimethyl formamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred for 10 minutes
2. 2
   workup.ADDITIONwas added to the above prepared mixture at -10° to --20° C.
3. 3
   workup.STIRRINGthe resulting mixture was stirred for one hour at RT, whereafter it
4. 4
   ExtraktionThis mixture was extracted 2 times with 150 ml methylene chloride
5. 5
   SonstigeThe organic phase was dried
6. 6
   Sonstigeevaporated
7. 7
   SonstigeThe resulting residue was crystallized

Vorschrift

16.5 g of 4-methyl-3,4-dihydro-2H-1,4-benzodiazepine-2,5(1H)-dione and 11.7 g of K-t-butoxide was dissolved in 100 ml of dry dimethyl formamide (DMF) and the mixture was stirred for 10 minutes. Then 13.2 ml of diethylchlorophosphate was added and the resulting mixture was cooled to -20° C. and stirred for 10 minutes. A mixture of 10.8 g K-t-butoxide and 10.5 ml ethyl isocyanoacetate in 30 ml of dry DMF was added to the above prepared mixture at -10° to --20° C. and the resulting mixture was stirred for one hour at RT, whereafter it was poured into 8.7 ml acetic acid in 300 ml water. This mixture was extracted 2 times with 150 ml methylene chloride. The organic phase was dried and evaporated. The resulting residue was crystallized leaving 10 g of the title compound as crystals.

Quelle