Dichloromethane → 1H-Benzimidazole-7-carboxamide,2-(4-hydroxyphenyl)-

HRID 382354Notes

Reaction equation

HRID 382354 reaction equation
B(Br)(Br)Br.ClCCl.C[O:9][C:10]1[CH:15]=[CH:14][C:13]([C:16]2[NH:17][C:18]3[C:24]([C:25]([NH2:27])=[O:26])=[CH:23][CH:22]=[CH:21][C:19]=3[N:20]=2)=[CH:12][CH:11]=1>CO>[OH:9][C:10]1[CH:11]=[CH:12][C:13]([C:16]2[NH:20][C:19]3[CH:21]=[CH:22][CH:23]=[C:24]([C:25]([NH2:27])=[O:26])[C:18]=3[N:17]=2)=[CH:14][CH:15]=1

Participants

5

Reactant 3

HCID 6344DichloromethaneHCID 25134Boron tribromideHCID 178488846HCID 178488846, compound

Product 1

HCID 1355464821H-Benzimidazole-7-carboxamide,2-(4-hydroxyphenyl)-

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Under an argon atmosphere 1M boron tribromide in dichloromethane (3.8 ml, 3.79 mmol) was transferred to a flask containing 2-(4′-methoxyphenyl)benzimidazole-4-carboxamide (NU 1076 from Example 5) (202.4 mg, 0.758 mmol). The resulting solution was refluxed for 24 hours using an air condenser. The solvent was removed by distillation to complete dryness. The solid residue was treated with 10% NaOH (10 ml), followed by dropwise addition of concentrated hydrochloric acid to neutralise (pH 7). The white precipitate was collected by filtration and dissolved in ethyl acetate (0 ml). The organic solvent was washed with water (2×3 ml), dried over MgSO4, and the product was obtained by removal of the solvent under reduced pressure. (109.5 mg, 57%). mp 266-267° C.; Found C 63.27, H 4.37, N 15.67 C14H11N3O2.0.75 MeOH requires C 63.04 H 4.69 N 15.76; vmax(cm−1) 3424.01, 3384.16, 3309.20, 3249.55, 3155.62, 1642.35, 1618.02, 1594.50, 1577.74; δH 7.03-7.07 (2H, d, J=8.5), 7.34-7.42 (1H, t), 7.75-7.79 (1H, d), 7.85 (1H, br s), 7.90-7.94 (1H, d), 8.15-8.19 (2H, d, J=8.5), 9.4-9.6 (1H, br s), 10.0-10.4 (1H, br s), 13.0-13.4 (1H, br s); m/z (EI) 253 (M+), 236, 208, 93.

Workup

  1. temperatureThe resulting solution was refluxed for 24 hours
  2. customThe solvent was removed by distillation
  3. additionThe solid residue was treated with 10% NaOH (10 ml)
  4. additionfollowed by dropwise addition of concentrated hydrochloric acid
  5. filtrationThe white precipitate was collected by filtration
  6. dissolutiondissolved in ethyl acetate (0 ml)
  7. washThe organic solvent was washed with water (2×3 ml)
  8. dry with materialdried over MgSO4
  9. customthe product was obtained by removal of the solvent under reduced pressure

Sources & evidence

ORD record
ord-659dba3019134a27ae50d5eff4de1377
Source dataset
uspto-grants-2001_10
Patent number
US06310082B1

Reaction notes

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