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

HRID 1902404Notes

Reaction equation

HRID 1902404 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-adbe97d38e64417db97e5b1116bf42eb
Source dataset
uspto-grants-1982_12
Patent number
US04363762

Reaction notes

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