反应详情

1.10 g of ethyl α-amino-1,3,4,5-tetrahydro-4-methyl-5-oxo-2H-1,4-benzodiazepin-2-ylidene-acetate are dissolved in 15 ml of toluene and treated with 1.0 ml of triethyl orthoformate. The mixture is heated to reflux for 50 minutes, subsequently cooled and evaporated in vacuo. The crystalline residue is suspended in 25 ml of ethyl acetate, filtered off and dried. There is obtained ethyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylate of melting point 165° C.

1. temperatureThe mixture is heated
2. temperatureto reflux for 50 minutes
3. temperaturesubsequently cooled
4. customevaporated in vacuo
5. filtrationfiltered off
6. customdried