3-(4-Hydroxy-phenyl)-isoxazole-5-carboxylic acid amide (which may be prepared as described in Preparation of Intermediate 2; 50 mg, 0.245 mmol) was dissolved in DMF (1.5 mL). K2CO3 (42 mg, 0.30 mmol), tetrabutylammonium iodide (14 mg, 0.038 mmol), and 1-bromomethyl-2-methylsulfonyl-benzene (which is available from Combi-Blocks; 62 mg, 0.25 mmol) were added. The reaction mixture was heated at 40° C. for 13 h. The reaction mixture was cooled to room temperature and partitioned between H2O (5 mL) and EtOAc (5 mL). The organic layer was dried (Na2SO4), filtered, evaporated, and purified twice by chromatography (40-60% EtOAc/hexanes) to give 3-[4-(2-methanesulfonyl-benzyloxy)-phenyl]-isoxazole-5-carboxylic acid amide (3 mg, 3%) as a white powder. HRMS Calcd. for C18H17N2O5S (M+H)+, 373.0853. Found: 373.0854.
