A solution of 2-((1R)-1-{2-[(benzyloxy)amino]-2-oxoethyl}-4-cyclohexylbutyl)-N,N,5-trimethyl-1,3-oxazole-4carboxamide (Preparation 73) (105 mg, 0.23 mmol) in ethanol (5 ml) was treated with 5% palladium on barium sulphate (45 mg) and ammonium formate (73 mg, 1.15 mmol) and the mixture was heated at 45° C. for 17 hours. Further palladium on barium sulphate (30 mg) and ammonium formate (60 mg, mmol) were added and the heating was continued for 2 hours. The solution was filtered through Arbocel® and the solvent removed from the filtrate under reduced pressure. The residue was azeotroped from dichloromethane (×3) then purified by column chromatography on silica gel eluting with dichloromethane:methanol:0.88 ammonia (98:2:0.2 to 90:10:1) to afford the title compound as a foam (25 mg).
