Water → 3-[3-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-pentanedioic acid monomethyl ester

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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 (70 mg, 0.17 mmol) is dissolved in DMF (1.5 mL) at room temperature and pyridinium dichromate (250 mg, 0.66 mmol) is added into it. The mixture is stirred for 20 hr and water (25 mL) is added. The pH of the solution is adjusted to pH 5 by adding acetic acids and the mixture is extracted with EtOAc (3×50 mL). The organic layers are combined, dried and concentrated to give crude product. Purification by preparative TLC using 80% EtOAc in Hexanes with 1% acetic acid affords 48 mg (66%) of 3-[3-(4-Methyl-benzo[b]thiophen-3-ylmethyl)-2-oxo-2,3-dihydro-benzimidazol-1-yl]-pentanedioic acid monomethyl ester. LCMS (ESMS): m/z 439.17 (M+H+).

Provenance & Evidence