Tributylphosphine → 3-{4-[1-(2,6-Dimethyl-4'-trifluoromethyl-biphenyl-4-yl)-3-methyl-butoxy]-benzoylamino}-propionic acid methyl ester

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Reaction Steps

To a solution of 1-(2,6-dimethyl-4′-trifluoromethyl-biphenyl-4-yl)-3-methyl-butan-1-ol (270 mg, 0.8 mmol) in toluene (8 mL) is added 1,1′-(azodicarbonyl) dipiperidine (ADDP, 304 mg, 1.21 mmol) at 0° C., followed by the addition of tributylphosphine (0.3 mL, 12.1 mmol) and 3-(4-hydroxy-benzoylamino)-propionic acid methyl ester (215 mg, 0.96 mmol). The reaction mixture is warmed up to room temperature and stirred overnight. The mixture is loaded on silica gel, eluted with hexanes with a gradient from 0% of ethyl acetate to 100% of ethyl acetate giving 3-{4-[1-(2,6-dimethyl-4′-trifluoromethyl-biphenyl-4-yl)-3-methyl-butoxy]-benzoylamino}-propionic acid methyl ester. The ester product is taken into methanol (2 mL), treated with sodium hydroxide (5N aqueous, 1 mL) for 5 h at room temperature. The mixture is concentrated, diluted with ethyl acetate, acidified with 5 N HCl (1.1 mL), extracted with ethyl acetate. The organic layers are dried and concentrated to afford 51 mg of the titled compound. MS (ES): 528.3 [M+H]+.

Provenance & Evidence