反应详情

To a solution of 13.5 g. of 5-(2-chlorophenyl)-3H-1,4-benzodiazepin-2(1H)-one in 60 ml. of concentrated sulfuric acid, a solution of 5.5 g. of potassium nitrate in 20 ml. concentrated sulfuric acid is added dropwise. The solution is then heated in a bath at 45-50° for 2 1/2 hours, cooled and poured on ice. After neutralizing with ammonia, the formed precipitate is filtered off and boiled with ethanol. A small amount of white insoluble material is then filtered off. The alcoholic solution on concentration yields crystals of 7-nitro-5-(2-chlorophenyl)-3H-1,4-benzodiazepin-2(1H)-one (clonazepam) which, after recrystallization from dichloromethane, melt at 238-240°.

1. temperatureThe solution is then heated in a bath at 45-50° for 2 1/2 hours
2. temperaturecooled
3. additionpoured on ice
4. filtrationthe formed precipitate is filtered off
5. filtrationA small amount of white insoluble material is then filtered off
6. concentrationThe alcoholic solution on concentration