5-(2,4-Bis-benzyloxy-5-chloro-phenyl)-isoxazole-3-carboxylic acid ethylamide (0.90 g, 1.94 mmol), N-Iodosuccinimide (0.44 g, 1 equiv.) and Ammonium cerium (IV) nitrate (0.53 g, 0.5 equiv) were suspended in Acetonitrile (55 ml) before heating to reflux (oil bath 100° C.) where upon the mixture became homogeneous. After 18 hrs the solution was cooled and the solvent removed in vacuo to give a thick orange oil. This was partitioned between DCM (25 ml) and water (10 ml), the organic layer was kept and washed with brine (2×25 ml) before drying over Na2SO4. The DCM was removed in vacuo to provide 0.88 g (77% yield) of the product as a orange/tan coloured powder.
