Ammonia → Clonazepam

Participants

Reaction Steps

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°.

Provenance & Evidence