3-Methyl Flunitrazepam → rac-7-amino-5(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one

HRID 848125Notes

Reaction equation

HRID 848125 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[C:8]1[C:14]2[CH:15]=[C:16]([N+:19]([O-])=O)[CH:17]=[CH:18][C:13]=2[N:12]([CH3:22])[C:11](=[O:23])[CH:10]([CH3:24])[N:9]=1>Cl>[NH2:19][C:16]1[CH:17]=[CH:18][C:13]2[N:12]([CH3:22])[C:11](=[O:23])[CH:10]([CH3:24])[N:9]=[C:8]([C:3]3[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=3[F:1])[C:14]=2[CH:15]=1

Participants

3

Reactant 1

HCID 205623323-Methyl Flunitrazepam

Product 1

HCID 20562337rac-7-amino-5(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

85 g (0.26 M) of rac-5-(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-7-nitro-2H-1,4-benzodiazepin-2-one are dissolved in 700 ml of concentrated hydrochloric acid and treated slowly with 180 g of stannous chloride. After about 15 minutes, the mixture is cooled with ice and then concentrated on a rotary evaporator. The residue is dissolved in ice-water, slowly made alkaline with 200 g of sodium carbonate in 1 liter of water and extracted several times with methylene chloride. The organic solution is dried over sodium sulphate, filtered and concentrated. The residue is crystallised from ethyl acetate and there is obtained rac-7-amino-5(o-fluorophenyl)-1,3-dihydro-1,3-dimethyl-2H-1,4-benzodiazepin-2-one which melts at 178°-180° C.

Workup

  1. temperaturethe mixture is cooled with ice
  2. concentrationconcentrated on a rotary evaporator
  3. dissolutionThe residue is dissolved in ice-water
  4. extractionslowly made alkaline with 200 g of sodium carbonate in 1 liter of water and extracted several times with methylene chloride
  5. dry with materialThe organic solution is dried over sodium sulphate
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue is crystallised from ethyl acetate

Sources & evidence

ORD record
ord-80a8fe5e178e4ac2a43cdf7f0f191005
Source dataset
uspto-grants-1981_10
Patent number
US04294758

Reaction notes

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