Sodium Hydroxide → 2H-Benzimidazol-2-one, 1,3-dihydro-5-hydroxy-

HRID 1750110Notes

Reaction equation

HRID 1750110 reaction equation
C[O:2][C:3]1[CH:12]=[CH:11][C:6]2[NH:7][C:8](=[O:10])[NH:9][C:5]=2[CH:4]=1.[OH-].[Na+]>I>[OH:2][C:3]1[CH:12]=[CH:11][C:6]2[NH:7][C:8](=[O:10])[NH:9][C:5]=2[CH:4]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 5911011,3-Dihydro-5-methoxy-2H-benzimidazol-2-one

Product 1

HCID 136166402H-Benzimidazol-2-one, 1,3-dihydro-5-hydroxy-Yield 511.7%

Reagents, catalysts & solvents 1

HCID 24841Hydrogen iodideSolvent

Conditions

Temperature
130 °C

Procedure

A mixture of intermediate 37 (3.6 g, 22 mmol) and 48% hydrogen iodide (30 mL) was heated to reflux (130° C.) and stirred for 12 h. The reaction mixture was neutralized to pH=8 with aq NaOH and then extracted with EtOAc. The combined organic layers were dried over anhydrous Na2SO4, concentrated under vacuum and purified by flash chromatography on silica gel column (elution with DCM/MeOH=80:1) to give 5-hydroxy-1H-benzo[d]imidazol-2(3H)-one (intermediate 38) (16.9 g, 80%). HPLC: 99%, RT 1.377 min. MS (ESI) m/z 151.0 [M+H]+. mp: 186-187° C.

Workup

  1. temperaturewas heated
  2. extractionextracted with EtOAc
  3. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  4. concentrationconcentrated under vacuum
  5. custompurified by flash chromatography on silica gel column (elution with DCM/MeOH=80:1)

Sources & evidence

ORD record
ord-fdc58e521c1d4eb1be16cc9be88c4cc3
Source dataset
uspto-grants-2015_10
Patent number
US09156822B2

Reaction notes

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