1-Phenylcyclopentanecarboxylic acid → (s)-1-Phenyl-cyclopentanecarboxylic acid [2-(4-benzyloxy-phenyl)-1-tert-butylcarbamoyl-ethyl]-amide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1-Phenyl-1-cyclopentanecarboxylic acid (0.171 g, 0.899 mmol) was dissolved in dry DMF (3 mL) under a nitrogen atmosphere and cooled to 0° C. in an ice-water bath. To this solution were added in succession N,N-diisopropylethylamine (0.310 mL, 1.80 mmol) and solid O-benzotriazol-1-yl-N,N,N′,N′-tetramethyluronium hexafluorophosphate (0.341 g, 0.899 mmol, Novabiochem, La Jolla, Calif.). The resulting reaction mixture was stirred at 0° C. for 30 minutes, (S)-2-Amino-3-(4-benzyloxy-phenyl)-N-tert-butyl-propionamide (0.293 g, 0.899 mmol) was then added. After an additional 60 minutes stirring at 0° C. the reaction mixture was mixed with 60 mL of diethyl ether. The resulting mixture was successively washed with 5% aqueous HCl solution, brine, saturated aqueous NaHCO3 solution and brine, and was dried over Na2SO4. The solution was concentrated in vacuo, and an oil was obtained. The crude residue was purified by chromatography (silica gel, 60% ether in hexanes) to give the title compound as a white foam (0.20 g, 45%); mp 40-50° C.

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