tert-Butanol → 1-{4'-[4-(2-Amino-ethyl)-3-methyl-isoxazol-5-yl]-biphenyl-4-yl}-cyclopropanecarboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

1-{4′-[4-(2-Carboxy-ethyl)-3-methyl-isoxazol-5-yl]-biphenyl-4-yl}-cyclopropanecarboxylic acid ethyl ester (0.825 g, 1.97 mmol), tert-butanol (0.21 mL, 2.16 mmol), diphenylphosphoryl azide (0.47 mL, 2.16 mmol), and triethylamine (0.3 mL, 2.16 mmol) were combined in toluene (8 mL) and stirred at 100° C. for 4 hours. The reaction was cooled to 80° C. and additional tert-butanol (0.21 mL, 2.16 mmol) was added. After stirring overnight at 80° C., the reaction was cooled to room temperature and submitted to aqueous workup. The crude material was purified by silica gel chromatography (0-100% EtOAc in hexanes). Then, the isolated product was treated with 4 N HCl in 1,4-dioxane and stirred at 60° C. overnight. The solution was filtered and concentrated to give the title compound.

Provenance & Evidence