Tributylphosphine → 3-(4-{1-[2-(4-Bromo-phenyl)-4-isopropyl-oxazol-5-yl]-ethoxy}-2-methyl-phenyl)-propionic acid methyl ester

Participants

Reaction Steps

To a solution of 1-[2-(4-bromo-phenyl)-4-isopropyl-oxazol-5-yl]-ethanol (9.05 g, 29.2 mmol) in toluene (300 ml) at 0° C. is added tri-n-butylphosphine (7.70 g, 38.1 mmol) and 1,1′-(azodicarbonyl)-dipiperidine (8.84 g, 35.0 mmol), followed by addition of 3-(4-hydroxy-2-methyl-phenyl)-propionic acid methyl ester (6.30 g, 32.1 mmol). The resulting mixture is stirred for 18 hours while warmed up to room temperature. The reaction is quenched with water (100 ml) and the aqueous layer is extracted with EtOAc (2×100 ml). The combined organics are dried over Na2SO4 and concentrated, purified by silica gel chromatography (Hexanes/EtOAc, 9/1 to 8.5/1.5) to afford the 3-(4-{1-[2-(4-bromo-phenyl)-4-isopropyl-oxazol-5-yl]-ethoxy}-2-methyl-phenyl)-propionic acid methyl ester as a colorless oil (11.4 g, 80%). MS (MH+): 488.1.

Provenance & Evidence