CID 66185 → 1-{[3-(Tert-butyl-dimethylsilanyloxy)-propyl]-[4-(4-fluorophenoxy)benzenesulfonyl]-amino}cyclopentanecarboxylic acid benzyl ester

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Reaction Steps

To a solution of 1-[4-(4-fluorophenoxy)benzenesulfonylamino]-cyclopentanecarboxylic acid benzyl ester (199 grams, 0.42 mole) in dry N,N-dimethylformamide (2.5 L) at room temperature was added potassium hexamethyldisilazide (100 grams, 0.50 mole) and, after 3 hours, tert-butyl-(3-iodopropoxy)dimethylsilane (150 grams, 0.50 mole). The resulting mixture was stirred at room temperature for 16 hours. Additional tert-butyl-3-iodopropoxy)-dimethylsilane (20 grams, 0.067 mole) was then added. Stirring at room temperature was continued for a further 3.5 hours. The mixture was quenched by addition of saturated ammonium chloride solution. The N,N-dimethylformamide was removed by evaporation under vacuum. The residue was taken up in diethyl ether and washed with water and brine. After drying over magnesium sulfate, the diethyl ether was evaporated to afford crude 1-{[3-(tert-butyl-dimethylsilanyloxy)-propyl]-[4-(4-fluorophenoxy)benzenesulfonyl]-amino}cyclopentanecarboxylic acid benzyl ester as an amber oil (279.6 grams).

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