Ethyl 3-hydroxycyclopentanecarboxylate → Ethyl 3-{[5-(biphenyl-4-yl)-6-chloro-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-benzimidazol-2-yl]oxy}cyclopentanecarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-(biphenyl-4-yl)-6-chloro-2-(methylsulfonyl)-1-{[2-(trimethylsilyl)ethoxy]methyl}-1H-benzimidazole (Intermediate 3, 0.350 g, 0.682 mmol) and ethyl 3-hydroxycyclopentanecarboxylate (Intermediate 9, 0.647 mL, 4.09 mmol) in 2.3 mL DMF was added DSU (0.514 mL. 3.41 mmol) dropwise via syringe. The reaction was heated overnight at 80° C., then diluted with EtOAc, and washed with H2O and brine. The aqueous layer was further extracted with EtOAc, and the combined organic layers were dried over Na2SO4, filtered, and concentrated. Purification of the resulting residue by preparative TLC (25% EtOAc/hexanes) furnished the desired compound as a pale yellow oil. LCMS: calculated for C33H39ClN2O4Si 591.21, observed m/e 591.04 M+ (Rt 3.06/4 min).

Provenance & Evidence