Flumazenil → Flumazenil Impurity 8

HRID 2198696Notes

Reaction equation

HRID 2198696 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[CH:12]=[N:13][C:14]([C:15]([O:17][CH2:18]C)=[O:16])=[C:10]3[CH2:9][N:8]([CH3:20])[C:7](=[O:21])[C:6]=2[CH:22]=1.[C-]#N.[K+]>CO>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[CH:12]=[N:13][C:14]([C:15]([O:17][CH3:18])=[O:16])=[C:10]3[CH2:9][N:8]([CH3:20])[C:7](=[O:21])[C:6]=2[CH:22]=1

Participants

4

Reactant 2

HCID 3373FlumazenilHCID 9032Potassium Cyanide

Product 1

HCID 20515347Flumazenil Impurity 8

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 3.5 g (11.5 mmol) of ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate, 0.15 g of potassium cyanide and 40 ml of methanol is stirred at the boiling point for 2.5 hours. The solvent is distilled off on a rotary evaporator and the residue is taken up in chloroform. After filtration from insoluble material, the filtrate is concentrated. After recrystallisation of the residue from ethyl acetate, there is obtained methyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of melting point 195°-196.5° C.

Workup

  1. distillationThe solvent is distilled off on a rotary evaporator
  2. filtrationAfter filtration from insoluble material
  3. concentrationthe filtrate is concentrated
  4. customAfter recrystallisation of the residue from ethyl acetate

Sources & evidence

ORD record
ord-9692dce089904a06a0801f72e15214ac
Source dataset
uspto-grants-1982_11
Patent number
US04359420

Reaction notes

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