Imidazole → HCID 22876422, compound

Participants

Reaction Steps

5.08 g (9.81 mmol) of 5(S)-(Boc-amino)-4(S)-hydroxy-6-phenyl-2(R)-{[p-(2-phenylethyl)phenyl]methyl}hexanoic acid in 22 ml of DMF are silylated, under a protective gas, with 6.80 g (45.1 mmol) of tert-butyldimethylchlorosilane and 5.48 g (80.4 mmol) of imidazole at RT for 20 h. The reaction mixture is poured onto 500 ml of ice-water, and this mixture is extracted 3× with ethyl acetate. The organic phases are washed with 10% citric acid solution, 2× water and saline, dried with Na2SO4 and evaporated. The residue is dissolved in 119 ml of methanol and 46 ml of THF, and this solution is treated with 8.1 g of potassium carbonate and 46 ml of water, and then stirred at RT for 17 h. The reaction mixture is subsequently poured onto ice-cold 10% citric acid solution, and this mixture is extracted 3× with ethyl acetate. The organic phases are washed with 2 portions of water and saline, dried with Na2SO4 and evaporated. Column chromatography (SiO2, hexane/ethyl acetate 2:1→1:1→ethyl acetate) results in the pure title compound: TLC Rf (D)=0.22; tRet (II)=23.3 min.

Provenance & Evidence