5,6-Dichloro-2-(4-methoxy-3-nitro-phenyl)-benzoimidazole-1-carboxylic acid benzyl ester → 2-(3-Amino-4-methoxy-phenyl)-5,6-dichloro-benzoimidazole-1-carboxylic acid benzyl ester

HRID 25499Notes

Reaction equation

HRID 25499 reaction equation
[CH2:1]([O:8][C:9]([N:11]1[C:15]2[CH:16]=[C:17]([Cl:21])[C:18]([Cl:20])=[CH:19][C:14]=2[N:13]=[C:12]1[C:22]1[CH:27]=[CH:26][C:25]([O:28][CH3:29])=[C:24]([N+:30]([O-])=O)[CH:23]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1>[Zn].C(O)(=O)C>[CH2:1]([O:8][C:9]([N:11]1[C:15]2[CH:16]=[C:17]([Cl:21])[C:18]([Cl:20])=[CH:19][C:14]=2[N:13]=[C:12]1[C:22]1[CH:27]=[CH:26][C:25]([O:28][CH3:29])=[C:24]([NH2:30])[CH:23]=1)=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 1

HCID 698015975,6-Dichloro-2-(4-methoxy-3-nitro-phenyl)-benzoimidazole-1-carboxylic acid benzyl ester

Product 1

HCID 102751152-(3-Amino-4-methoxy-phenyl)-5,6-dichloro-benzoimidazole-1-carboxylic acid benzyl esterYield 56.5%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Procedure

5,6-Dichloro-2-(4-methoxy-3-nitro-phenyl)-benzoimidazole-1-carboxylic acid benzyl ester (1.14 g, 2.4 mmol) from Step B was combined with glacial acetic acid (50 mL). Zinc dust (7.81 g, 120 mmol) was then gradually added to the stirred reaction mixture. After 2 hours, the zinc was filtered from the reaction mixture and the filtrate concentrated to an oil via rotary evaporation (60° C.). The oil was taken up in ethyl acetate and washed with saturated aqueous sodium bicarbonate solution and brine, dried (magnesium sulfate), filtered and the solvent removed. The solid was triturated with 7:3 hexane:ethyl acetate to give the product (0.6 g), mp 150-160° C.

Workup

  1. filtrationthe zinc was filtered from the reaction mixture
  2. concentrationthe filtrate concentrated to an oil via rotary evaporation (60° C.)
  3. washwashed with saturated aqueous sodium bicarbonate solution and brine
  4. dry with materialdried (magnesium sulfate)
  5. filtrationfiltered
  6. customthe solvent removed
  7. customThe solid was triturated with 7:3 hexane

Sources & evidence

ORD record
ord-464cd0e7f58342a68184274ec6d685a9
Source dataset
uspto-grants-2005_02
Patent number
US06858739B2

Reaction notes

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