Dimethylformamide → 4,5,6-trichloro-1H-benzoimidazole

HRID 538193Notes

Reaction equation

HRID 538193 reaction equation
[Cl:1][C:2]1[C:7]([Cl:8])=[C:6]([Cl:9])[CH:5]=[C:4]([N+:10]([O-])=O)[C:3]=1[NH2:13].S(S([O-])=O)([O-])=O.[Na+].[Na+].[CH:22](OC)(OC)OC.CN(C=O)C>C(O)(=O)C>[Cl:1][C:2]1[C:3]2[N:13]=[CH:22][NH:10][C:4]=2[CH:5]=[C:6]([Cl:9])[C:7]=1[Cl:8]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 9005Trimethyl orthoformateHCID 24489Sodium DithioniteHCID 107052972,3,4-Trichloro-6-nitrobenzenamine

Product 1

HCID 3445854,5,6-trichloro-1H-benzoimidazoleYield 43%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 2,3,4-trichloro-6-nitro-phenylamine (0.250 g, 1.04 mmol), sodium dithionite (0.907 g, 5.21 mmol), trimethyl orthoformate (4 ml), DMF (4 mL), and acetic acid (0.5 mL) was heated in a sealed tube for 15 h at 100° C. The reaction mixture was cooled to 23° C. and partitioned between EtOAc and saturated aqueous NaHCO3. The organic layer was collected and the aqueous layer was extracted with EtOAc. The combined organic layers were dried (MgSO4), filtered, and concentrated to yield the titled compound (0.098 g, 43%). MS (ESI/CI): mass calcd. for C7H3Cl3N2, 219.9; m/z found, 221.0 [M+H]+. 1H NMR (400 MHz, DMSO-d6): 13.16 (s, 1H), 8.43 (s, 1H), 7.90 (s, 1H).

Workup

  1. temperatureThe reaction mixture was cooled to 23° C.
  2. custompartitioned between EtOAc and saturated aqueous NaHCO3
  3. customThe organic layer was collected
  4. extractionthe aqueous layer was extracted with EtOAc
  5. dry with materialThe combined organic layers were dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-5ac12312bc4043058eb10792e6bda741
Source dataset
uspto-grants-2014_10
Patent number
US08865713B2

Reaction notes

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