A solution 2-((1R)-1-{2-[(benzyloxy)amino]-2-oxoethyl}-4-cyclohexylbutyl)-5-methyl-1,3-oxazole-4-carboxylic acid (Preparation 72) (200 mg, 0.47 mmol), N-methylmorpholine (77 □1,0.70 mmol), 1-hydroxybenzotriazole hydrate (63 mg, 0.47 mmol)and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydochloride (134 mg, 0.70 mmol) in dichloromethane (10 ml) was treated with N,N-dimethylethylenediamine (56 □1,0.51 mmol) and stirred at room temperature for 18 hours. The reaction mixture was diluted with dichloromethane and washed with water, saturated sodium hydrogen carbonate solution and brine, dried over anhydrous magnesium sulphate, filtered and the solvent removed under reduced pressure. The residue was purified by column chromatography on silica gel eluting with a system of 94:4:0.4 (dichloromethane:methanol:ammonia) to afford the title compound as a white solid (216 mg).
