Formamide → Estazolam

HRID 1764512

Reaction equation

HRID 1764512 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]=[C:10]([NH:12][NH2:13])[CH2:9][N:8]=[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[C:6]=2[CH:20]=1.[CH:21](N)=O.S(=O)(=O)(O)O.C(=O)(O)[O-].[Na+]>O>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[N:11]3[CH:21]=[N:13][N:12]=[C:10]3[CH2:9][N:8]=[C:7]([C:14]3[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=3)[C:6]=2[CH:20]=1

Participants

6

Reactant 4

HCID 713FormamideHCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 123908747-Chloro-2-hydrazinyl-5-phenyl-3H-1,4-benzodiazepine

Product 1

HCID 3261Estazolam

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a suspension of 2.8 parts of 7-chloro-2-hydrazino 5-phenyl-3H-1,4-benzodiazepine in 40 parts by volume of formamide is added 1 part by volume of concentrated sulfuric acid. The resulting solution is left standing for 6 hours and then warmed on a boiling water bath for 30 minutes. The solution is diluted with water, neutralized with sodium bicarbonate and extracted with chloroform. The chloroform extract is washed with water and dried over anhydrous sodium sulfate, followed by evaporation of the solvent. The residue is recrystallized from ethyl acetate to give 8-chloro-6-phenyl-4H-s-triazolo [4,3-a][1,4] benzodiazepine as colorless flakes. Melting point: 226° C to 227° C.

Workup

  1. waitThe resulting solution is left
  2. temperaturewarmed on a boiling water bath for 30 minutes
  3. extractionextracted with chloroform
  4. extractionThe chloroform extract
  5. washis washed with water
  6. dry with materialdried over anhydrous sodium sulfate
  7. customfollowed by evaporation of the solvent
  8. customThe residue is recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-d3a6908b9fdc482f960c84e892097c9e
Source dataset
uspto-grants-1978_09
Patent number
US04116956

Linked notes

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