Difluoroacetic acid → 4-bromo-2-(difluoromethyl)-6-nitro-1H-benzo[d]imidazole

HRID 1622476Notes

Reaction equation

HRID 1622476 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([N+:8]([O-:10])=[O:9])[CH:5]=[C:4]([NH2:11])[C:3]=1[NH2:12].[F:13][CH:14]([F:18])[C:15](O)=O>C1(C)C=CC=CC=1.CCOC(C)=O>[Br:1][C:2]1[C:3]2[N:12]=[C:15]([CH:14]([F:18])[F:13])[NH:11][C:4]=2[CH:5]=[C:6]([N+:8]([O-:10])=[O:9])[CH:7]=1

Participants

5

Reactant 2

HCID 9788Difluoroacetic acidHCID 203480123-Bromo-5-nitrobenzene-1,2-diamine

Product 1

HCID 866878364-bromo-2-(difluoromethyl)-6-nitro-1H-benzo[d]imidazoleYield 97%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
105 °C

Procedure

To a 100 mL round bottomed flask was added 3-bromo-5-nitrobenzene-1,2-diamine (5.5 g, 23.70 mmol) and 2,2-difluoroacetic acid (4.46 mL, 71.1 mmol) in Toluene (55 mL). The stirred solution was heated to 105° C. and monitored by LC/MS. After stirring at 105° C. for 2 hr the reaction was allowed to cool to rt, was diluted with EtOAc (20 mL) and filtered through celite. The filtrate was concentrated in-vacuo then taken up in EtOAc, washed several times with sat'd NaHCO3 soln, brine and then dried over Na2SO4 and concentrated to provide crude 4-bromo-2-(difluoromethyl)-6-nitro-1H-benzo[d]imidazole (6.7 g, 22.94 mmol, 97% yield) as a brown solid. LC/MS: MS (ES+) m/e 293.7 [M+H]+.

Workup

  1. temperatureto cool to rt
  2. filtrationfiltered through celite
  3. concentrationThe filtrate was concentrated in-vacuo
  4. washwashed several times with sat'd NaHCO3 soln
  5. dry with materialbrine and then dried over Na2SO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-532e1d4331254702a6975b277ae98bad
Source dataset
uspto-grants-2014_07
Patent number
US08778937B2

Reaction notes

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