O-Phenylenediamine → 2-(1H-benzo[d]imidazol-2-yl)-4-chlorophenol

HRID 1776876Notes

Reaction equation

HRID 1776876 reaction equation
[C:1]1([NH2:8])[C:2]([NH2:7])=[CH:3][CH:4]=[CH:5][CH:6]=1.[Cl:9][C:10]1[CH:11]=[CH:12][C:13]([O:19]C)=[C:14]([CH:18]=1)[C:15](O)=O.[OH-].[K+]>>[NH:7]1[C:2]2[CH:3]=[CH:4][CH:5]=[CH:6][C:1]=2[N:8]=[C:15]1[C:14]1[CH:18]=[C:10]([Cl:9])[CH:11]=[CH:12][C:13]=1[OH:19]

Participants

4

Reactant 3

HCID 7243O-PhenylenediamineHCID 14797Potassium HydroxideHCID 769705-Chloro-o-anisic acid

Product 1

HCID 35112112-(1H-benzo[d]imidazol-2-yl)-4-chlorophenolYield 27%

Conditions

Temperature
200 °C

Procedure

A mixture of benzene-1,2-diamine (500 mg, 4.6 mmol), 5-chloro-2-methoxy-benzoic acid (1.3 g, 6.9 mmol) in PPA (30 mL) was allowed to stir at 200° C. for 5 hours. The mixture was poured to ice and neutralized with KOH. The mixture was extracted with ethyl acetate. The organic layer was washed with brine and dried over Na2SO4. The organic phase was concentrated to provide 2-(1H-benzo[d]imidazol-2-yl)-4-chlorophenol (300 mg, yield: 27%). 1H-NMR (DMSO-d6, 400 MHz) δ 8.20 (d, J=2.5 Hz, 1H), 7.73˜7.70 (m, 2H), 7.44 (dd, J=8.8, 2.6 Hz, 1H), 7.34˜7.32 (m, 2H), 7.10 (d, J=8.8 Hz, 1H). MS (M+H)+: 245.

Workup

  1. extractionThe mixture was extracted with ethyl acetate
  2. washThe organic layer was washed with brine
  3. dry with materialdried over Na2SO4
  4. concentrationThe organic phase was concentrated

Sources & evidence

ORD record
ord-855e7ec547f94428aa6dd0d58eabbd74
Source dataset
uspto-grants-2016_02
Patent number
US09265773B2

Reaction notes

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