Flumazenil → ethyl 8-fluoro-5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

HRID 1447334Notes

Reaction equation

HRID 1447334 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][CH3:19])=[O:16])=[C:10]3[CH2:9][N:8]([CH3:20])[C:7](=O)[C:6]=2[CH:22]=1.COC1C=CC(P2(=S)SP(=S)(C3C=CC(OC)=CC=3)[S:32]2)=CC=1>C1(C)C=CC=CC=1>[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][CH3:19])=[O:16])=[C:10]3[CH2:9][N:8]([CH3:20])[C:7](=[S:32])[C:6]=2[CH:22]=1

Participants

4

Reactant 2

HCID 3373FlumazenilHCID 87949Lawesson's reagent

Product 1

HCID 20515334ethyl 8-fluoro-5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

10.7 g (35.3 mmol) of ethyl 8-fluoro-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]-benzodiazepine-3-carboxylate and 7.13 g (17.6 mmol) of 2,4-bis(p-methoxyphenyl)-1,3,2,4-dithiadiphosphetane-2,4-disulphide in 100 ml of toluene are heated to boiling under reflux for 22 hours. The mixture is subsequently concentrated in vacuo until crystallisation begins and is then left to stand in an ice-bath for 1 hour. The crystallised-out material is filtered off under suction and washed with a small amount of toluene. The mixture is separated on silica gel with ethyl acetate/chloroform (1:9). After recrystallisation from ethyl acetate, there is obtained pure ethyl 8-fluoro-5,6-dihydro-5-methyl-6-thioxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of melting point 157°-159° C.

Workup

  1. temperatureunder reflux for 22 hours
  2. concentrationThe mixture is subsequently concentrated in vacuo until crystallisation
  3. waitis then left
  4. filtrationThe crystallised-out material is filtered off under suction
  5. washwashed with a small amount of toluene
  6. customThe mixture is separated on silica gel with ethyl acetate/chloroform (1:9)
  7. customAfter recrystallisation from ethyl acetate

Sources & evidence

ORD record
ord-2849b489b51e4ab78bfd93770b47096d
Source dataset
uspto-grants-1982_02
Patent number
US04316839

Reaction notes

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