A mixture of (4-adamantan-1-yl-phenoxymethyl)-acetic acid (200.0 mg, 0.70 mmol) and 3-amino-4-hydroxy-benzoic acid methyl ester (164.3 mg, 0.98 mmol) in PPSE (3 mL) was heated at 140° C. for 2 h. At the end of the reaction period, the mixture was taken to dichloromethane and neutralized with 1 N NaOH solution. The organic layer was separated and the aqueous solution extracted with dichloromethane. The combined extracts were dried over anhydrous MgSO4, filtered and the solvent was removed with rotary evaporator under reduced pressure. The residue was purified by flash chromatography (n-Hexane:EtoAc:MeOH=6:3:1) to afford 2-(4-adamantan-1-yl-phenoxymethyl)-benzoxazole-5-carboxylic acid methyl ester as a white solid (187.3 mg, 64.1% yield).
