Flumazenil → Flumazenil Impurity 8

HRID 67489

Reaction equation

HRID 67489 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-7707367bc4b04173954be4eef17bcc3c
Source dataset
uspto-grants-1982_08
Patent number
US04346033

Linked notes

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