Hydrochloric Acid → 5-Hydroxy-3-[3-(4-methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-pentanoic acid

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Reaction Steps

5-Hydroxy-3-[3-(4-methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-pentanoic acid methyl ester and 1-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-3-(2-oxo-tetrahydro-pyran-4-yl)-1,3-dihydro-benzimidazol-2-one (51 mg) are dissolved in 1,4-dioxane (2.5 mL). Then 1.0 N NaOH solution (2.0 mL) is added and the mixture is stirred for 2 hr. Then 1.0 M HCl (3.0 mL) is added to make it acidic and the mixture is extracted with EtOAc (3×35 mL). The organic layers are combined, dried and concentrated to give crude product. Purification by preparative TLC using 7.5% MeOH in CH2Cl2 affords 43 mg (62% for two steps) of 5-Hydroxy-3-[3-(4-methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-pentanoic acid. LCMS (ESMS): m/z 411.07 (M+H+).

Provenance & Evidence