Sodium Hydroxide → 2-[4-(2-Butylbenzimidazol-1-yl)methylphenyl]benzoic acid

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Reaction Steps

1M Aqueous sodium hydroxide solution (6.5 ml) was added to a solution of methyl 4'-[(2-butyl-1H-benzimidazol-1-yl)methyl]biphenyl-2-carboxylate (A) (2.0 g) in ethanol (20 ml). The solution was heated under reflux for 3 hours and then volatile material was removed by evaporation. The residue was dissolved in water (20 ml) and the solution acidified to pH 4 with 20% aqueous citric acid. The precipitated solid was collected and dried under high vacuum to give 4'-[(2-butyl-1H-benzimidazol-1-yl)methyl]biphenyl-2-carboxylic acid (0.83 g), as a white powder, m.p. 225°-227° C.; NMR (d6 -DMSO): 0.9(t,3H), 1.4(m,2H), 1.7(m,2H), 2.85(t,3H), 5.5(s,2H), 7.15(m,4H), 7.3(m,3H), 7.4-7.7 (complex m,5H); 12.6(br, 1H); mass spectrum (positive chemical ionisation; hereinafter referred to as "+ve CI" ): 385 (M+H)+, 384 (M+), 355, 342, 298, 211, 165, 145, 132, 77; microanalysis found: C,77.2; H,6.5; N,7.0; C25H25N2.025 H2O requires: C,77.2; H,6.2; N,7.2%.

Provenance & Evidence