Phosphorus sulfide (P2S5) → 7-chloro 5-(2-chlorophenyl)-1,3-dihydro-2H-(1,4)-benzodiazepine-2-thione

HRID 1580644Notes

Reaction equation

HRID 1580644 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10](=O)[CH2:9][N:8]=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=3[Cl:19])[C:6]=2[CH:20]=1.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:22]>N1C=CC=CC=1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10](=[S:22])[CH2:9][N:8]=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][C:14]=3[Cl:19])[C:6]=2[CH:20]=1

Participants

4

Reactant 2

HCID 14817Phosphorus sulfide (P2S5)HCID 17925Delorazepam

Product 1

HCID 8267037-chloro 5-(2-chlorophenyl)-1,3-dihydro-2H-(1,4)-benzodiazepine-2-thione

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of (0.025 mole) of 1,3-dihydro-7-chloro-5-(2-chlorophenyl)-2H-1,4-benzodiazepin-2-one in about 500 ml. of pyridine is treated with 5.55 g. (0.025 mole) of phosphorus pentasulfide and heated under reflux in a nitrogen atmosphere for 2 hours. The pyridine is removed in vacuo and the thus-produced residue is poured onto crushed ice. The aqueous phase is extracted with methylene chloride and then discarded. The extract is washed successively with three 200-ml. portions of water and 100 ml. of brine, and dried over anhydrous sodium sulfate. Removal of the solvent gives a solid which is recrystallized from ethanol-water, to give crude material which, after recrystallization from ethanolwater, gives pure 1,3-dihydro-7-chloro-5-(2-chlorophenyl)-2H-1,4-benzodiazepine-2-thione, melting point 251°-253° C.

Workup

  1. temperatureunder reflux in a nitrogen atmosphere for 2 hours
  2. customThe pyridine is removed in vacuo
  3. additionthe thus-produced residue is poured
  4. customonto crushed ice
  5. extractionThe aqueous phase is extracted with methylene chloride
  6. washThe extract is washed successively with three 200-ml
  7. dry with materialof brine, and dried over anhydrous sodium sulfate
  8. customRemoval of the solvent
  9. customgives a solid which
  10. customis recrystallized from ethanol-water
  11. customto give crude material which
  12. customafter recrystallization from ethanolwater

Sources & evidence

ORD record
ord-5b11856449e04e038253543b61a8de55
Source dataset
uspto-grants-1976_01
Patent number
US03933794

Reaction notes

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