1,1'-Carbonyldiimidazole → Ethyl 4-(2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)benzoate

HRID 1270366Notes

Reaction equation

HRID 1270366 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[NH:8][C:9]1[CH:19]=[CH:18][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][CH:10]=1.[C:20](N1C=CN=C1)(N1C=CN=C1)=[O:21]>C1COCC1>[O:21]=[C:20]1[N:8]([C:9]2[CH:19]=[CH:18][C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:11][CH:10]=2)[C:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=2[NH:1]1

Participants

4

Reactant 2

HCID 682631,1'-CarbonyldiimidazoleHCID 18449398Ethyl 4-[(2-aminophenyl)amino]benzoate

Product 1

HCID 18449399Ethyl 4-(2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)benzoate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
75 °C

Procedure

A mixture of ethyl 4-[(2-aminophenyl)amino]benzoate from Step B (442 mg, 1.72 mmol) and 1,1′-carbonyldiimidazole (652 mg, 4.02 mmol) in THF (10 mL) was heated at 75° C. for 3 h. The cooled mixture was partitioned between EtOAc (100 mL) and 10% aqueous citric acid (50 mL). The organic layer was washed with H2O (30 mL), then brine (30 mL), then dried over Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel chromatography, eluting with a gradient of hexane::EtOAc—95:5 to 75:25, to give the title compound, which was of sufficient purity for use in the next step. MS: m/z=283 (M+1).

Workup

  1. customThe cooled mixture was partitioned between EtOAc (100 mL) and 10% aqueous citric acid (50 mL)
  2. washThe organic layer was washed with H2O (30 mL)
  3. dry with materialbrine (30 mL), then dried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customThe crude product was purified by silica gel chromatography
  7. washeluting with a gradient of hexane

Sources & evidence

ORD record
ord-333e9b8dbfa34da49cf62192346dff4f
Source dataset
uspto-grants-2007_04
Patent number
US07202251B2

Reaction notes

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