Formic Acid → 5-bromo-4-chloro-1H-benzoimidazole

HRID 475221Notes

Reaction equation

HRID 475221 reaction equation
[Br:1][C:2]1[C:3]([Cl:10])=[C:4]([NH2:9])[C:5]([NH2:8])=[CH:6][CH:7]=1.[OH-].[Na+].[CH:13](O)=O>>[Br:1][C:2]1[CH:7]=[CH:6][C:5]2[NH:8][CH:13]=[N:9][C:4]=2[C:3]=1[Cl:10]

Participants

4

Reactant 3

HCID 284Formic AcidHCID 14798Sodium HydroxideHCID 578001544-Bromo-3-chlorobenzene-1,2-diamine

Product 1

HCID 594744835-bromo-4-chloro-1H-benzoimidazoleYield 78%

Procedure

A mixture of 4-bromo-3-chloro-benzene-1,2-diamine (CASRN 1008361-80-5, 27 g, 0.1221 mol) and formic acid (80 mL) was heated to reflux for 1.5 h. After the completion of the reaction, 10% NaOH was added until the solution basic. The resulting solid was filtered and washed well with water then dried over night over suction to afford 22 g (78%) of 5-bromo-4-chloro-1H-benzoimidazole (128) as pale yellow solid which was used without additional purification.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 1.5 h
  3. additionwas added until the solution basic
  4. filtrationThe resulting solid was filtered
  5. washwashed well with water
  6. customthen dried over night over suction

Sources & evidence

ORD record
ord-2152470eec4c4135a9f5aaa1666b2842
Source dataset
uspto-grants-2014_01
Patent number
US08637537B2

Reaction notes

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