Ammonia → Clonazepam

HRID 725666

Reaction equation

HRID 725666 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8]1[C:14]2[CH:15]=[CH:16][CH:17]=[CH:18][C:13]=2[NH:12][C:11](=[O:19])[CH2:10][N:9]=1.S(=O)(=O)(O)O.[N+:25]([O-])([O-:27])=[O:26].[K+].N>>[N+:25]([C:16]1[CH:17]=[CH:18][C:13]2[NH:12][C:11](=[O:19])[CH2:10][N:9]=[C:8]([C:3]3[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=3[Cl:1])[C:14]=2[CH:15]=1)([O-:27])=[O:26]

Participants

5

Reactant 4

HCID 222AmmoniaHCID 1118Sulfuric Acid2×HCID 24434Potassium NitrateHCID 145904461,3-Dihydro-5-(2-chlorophenyl)-2H-1,4-benzodiozepin-2-one

Product 1

HCID 2802Clonazepam

Procedure

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°.

Workup

  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

Sources & evidence

ORD record
ord-ad0e7fb22a6a4b19a2c390a6a34d0ab0
Source dataset
uspto-grants-1998_01
Patent number
US05706829

Linked notes

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