4-Methylmorpholine → 2-((1R)-1-{2-[(Benzyloxy)amino]-2-oxoethyl}-4-cyclohexylbutyl)-N,N-dimethyl-1,3-oxazole-4-carboxamide

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Reaction Steps

A solution of 2-((1R)-1-{2-[(benzyloxy)amino]-2-oxoethyl}-4-cyclohexylbutyl)-1,3-oxazole-4-carboxylic acid (Preparation 65) (200 mg, 0.48 mmol) in dichloromethane (6 ml) was treated sequentially with 1-hydroxybenzotriazole hydrate (72 mg, 0.53 mmol), dimethylamine hydrochloride (79 mg, 0.96 mmol), N-methylmorpholine (160 μl, 1.45 mmol) and 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride (111 mg, 0.58 mmol) and the resulting mixture was stirred at room temperature under a nitrogen atmosphere for 4 hours. The solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate and washed sequentially with aqueous citric acid solution (10% w/v), a saturated aqueous solution of sodium hydrogen carbonate and brine, dried over anhydrous magnesium sulphate, filtered and the solvent removed under reduced pressure. The residue was then purified by column chromatography on silica gel eluting with dichloromethane:methanol:0.88 ammonia (95:5:0.5) to afford the title compound as a colourless oil (200 mg).

Provenance & Evidence