Sulfuric Acid → 9H-Dibenz(b,f)imidazo(1,2-d)(1,4)diazepine

HRID 1076202Notes

Reaction equation

HRID 1076202 reaction equation
CO[CH:3](OC)[CH2:4][NH:5][C:6]1[C:7]2[CH:20]=[CH:19][CH:18]=[CH:17][C:8]=2[NH:9][C:10]2[CH:16]=[CH:15][CH:14]=[CH:13][C:11]=2[N:12]=1.N1C=CN2C=1C1C=CC=CC=1NC1C=CC=CC2=1.S(=O)(=O)(O)O>>[N:5]1[CH:4]=[CH:3][N:12]2[C:6]=1[C:7]1[CH:20]=[CH:19][CH:18]=[CH:17][C:8]=1[NH:9][C:10]1[CH:16]=[CH:15][CH:14]=[CH:13][C:11]2=1

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 178495878HCID 178495878, compound

Product 1

HCID 30444909H-Dibenz(b,f)imidazo(1,2-d)(1,4)diazepineYield 70%

Procedure

9H-Dibenzo[b,f]imidazo[1,2-d][1,4]diazepine [(5H-dibenzo[b,e][1,4]diazepine-11-yl)amino]acetaldehyde dimethyl acetal (30.0 g., 101.0 mmol.) is dissolved in 100 ml. of concentrated sulfuric acid and stirred at room temperature for 3 hours. The product is isolated by pouring the acid solution cautiously, and in portions into ice-cold distilled water, and carefully adding the resulting slurry to 3.0 L. of cold 10% aqueous sodium hydroxide solution. The product is extracted with chloroform; the chloroform layer is back-extracted with 10% aqueous sodium hydroxide followed by washing with a brine soltuion and then the chloroform solution is dried over magnesium sulfate. After filtration and concentration in vacuo, a residue is obtained, which is dissolved in 800 ml. of hot ethyl acetate, filtered to remove insoluble material, and then concentrated to a volume of 500 ml. On colling, 16.34 g. (70.0%) of 9H-dibenzo[b,f]imidazo[1,2-d][1, 4]diazepine of melting point 215°-217° C. is obtained in the form of prisms. An additional 5.23 g. (22.4%) of product is obtained in two additional crops.

Workup

  1. customThe product is isolated
  2. additionby pouring the acid solution cautiously
  3. distillationin portions into ice-cold distilled water
  4. additioncarefully adding the resulting slurry to 3.0 L
  5. extractionThe product is extracted with chloroform
  6. extractionthe chloroform layer is back-extracted with 10% aqueous sodium hydroxide
  7. washby washing with a brine soltuion
  8. dry with materialthe chloroform solution is dried over magnesium sulfate
  9. filtrationAfter filtration and concentration in vacuo
  10. customa residue is obtained
  11. dissolutionwhich is dissolved in 800 ml
  12. filtrationof hot ethyl acetate, filtered
  13. customto remove insoluble material
  14. concentrationconcentrated to a volume of 500 ml

Sources & evidence

ORD record
ord-17f5e73bd15b422d8efed18506f4ee8f
Source dataset
uspto-grants-1976_05
Patent number
US03956297

Reaction notes

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