Phosphorus oxychloride → 2-Chloro-5,6-dinitrobenzimidazole
Reaction equation
[N+:1]([C:4]1[C:13]([N+:14]([O-:16])=[O:15])=[CH:12][C:7]2=[N:8][C:9](=O)[N:10]=[C:6]2[CH:5]=1)([O-:3])=[O:2].P(Cl)(Cl)([Cl:19])=O>>[N+:1]([C:4]1[C:13]([N+:14]([O-:16])=[O:15])=[CH:12][C:7]2[N:8]=[C:9]([Cl:19])[NH:10][C:6]=2[CH:5]=1)([O-:3])=[O:2]Participants
3
Procedure
As represented in the following synthesis scheme, 10 g of 2-benzoimidazolone was heated and stirred in 100 mL of nitric acid (1.38) at 70° C. for 1 hour, followed by diluting with cold water, to thereby obtain yellow green 5,6-dinitro-2-benzoimidazolone (yield 76.5%). The thus obtained 5,6-dinitro-2-benzoimidazolone was refluxed in phosphorous oxychloride at 140° C. for 7 hours, followed by evaporating the excessive phosphorous oxychloride under reduced pressure, and neutralizing with an aqueous solution of sodium hydrogen carbonate, to thereby obtain yellow 5,6-dinitro-2-chlorobenzimidazole the 2-position of which was chloridized (yield 64.7%).
Workup
- customby evaporating the excessive phosphorous oxychloride under reduced pressure
Sources & evidence
- ORD record
- ord-78624022d6884d3e9557c67970cc5689
- Source dataset
- uspto-grants-2012_12
- Patent number
- US08338609B2
Reaction notes
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