4,5-Dinitrobenzene-1,2-diamine → Phenyl 4-(5,6-dinitro-1H-benzimidazol-2-yl)benzoate

HRID 1414377Notes

Reaction equation

HRID 1414377 reaction equation
Cl[C:2]([C:4]1[CH:12]=[CH:11][C:7]([C:8]([O-:10])=[O:9])=[C:6](C2C=CC=CC=2)[CH:5]=1)=O.[NH2:19][C:20]1[CH:25]=[C:24]([N+:26]([O-:28])=[O:27])[C:23]([N+:29]([O-:31])=[O:30])=[CH:22][C:21]=1[NH2:32]>C1C(Cl)=CC=C(Cl)C=1>[C:8]([C:7]1[CH:6]=[CH:5][C:4]([C:2]2[NH:19][C:20]3[CH:25]=[C:24]([N+:26]([O-:28])=[O:27])[C:23]([N+:29]([O-:31])=[O:30])=[CH:22][C:21]=3[N:32]=2)=[CH:12][CH:11]=1)([O:10][C:4]1[CH:12]=[CH:11][CH:7]=[CH:6][CH:5]=1)=[O:9]

Participants

4

Reactant 2

HCID 44419034,5-Dinitrobenzene-1,2-diamineHCID 131710586HCID 131710586, compound

Product 1

HCID 21487229Phenyl 4-(5,6-dinitro-1H-benzimidazol-2-yl)benzoateYield 58%

Reagents, catalysts & solvents 1

HCID 46851,4-DichlorobenzeneSolvent

Procedure

To a solution containing 10 g (38.4 mmole) of p-chlorocarbonylphenylbenzoate dissolved in 100 ml of dichlorobenzene was added 2.53 g (12.8 mmole) of 1,2-diamino-4,5-dinitrobenzene. After heating the resulting mixture under nitrogen to reflux (frothing), it was maintained at that temperature for 2 hours. The solution was then allowed to cool in ice for one hour, and the precipitate that formed was filtered by suction, washed with benzene, and air-dried. The crude product was chromatographed on a 2× 18 inch dry column of silica gel. Elution with methylene chloride removed traces of impurities, while further elution of the column with 20/1 methylene chloride-THF slowly removed a broad band of the desired product, leaving a third band of side-product on the column. After all of the second band had been removed from the column, the solvent was removed in vacuo leaving a pale yellow residue. Recrystallization from THF-n-propanol yielded 3.0 g (58%) of 2-[p-carbophenoxyphenyl]-5,6-dinitrobenzimidazole as pale yellow needles, m.p. 239°-240°.

Workup

  1. temperatureAfter heating the resulting mixture under nitrogen
  2. temperatureto reflux (frothing), it
  3. temperaturewas maintained at that temperature for 2 hours
  4. temperatureto cool in ice for one hour
  5. customthe precipitate that formed
  6. filtrationwas filtered by suction
  7. washwashed with benzene
  8. customair-dried
  9. customThe crude product was chromatographed on a 2× 18 inch
  10. customdry column of silica gel
  11. washElution with methylene chloride removed traces of impurities
  12. washwhile further elution of the column with 20/1 methylene chloride-THF
  13. customslowly removed a broad band of the desired product
  14. customleaving a third band of side-product on the column
  15. customAfter all of the second band had been removed from the column
  16. customthe solvent was removed in vacuo
  17. customleaving a pale yellow residue
  18. customRecrystallization from THF-n-propanol

Sources & evidence

ORD record
ord-51cc99db22174f51bee68b467ab28c69
Source dataset
uspto-grants-1977_01
Patent number
US04001268

Reaction notes

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