Dicyclohexylcarbodiimide → N,N'-Dicyclohexylurea

Participants

Reaction Steps

Dicyclohexylcarbodiimide (963 mg, 4.67 mmol), 4-dimethylaminopyridine (574 mg, 4.70 mmol) and (R)-3-benzyloxytetradecanoic acid (1.50 g, 4.48 mmol) were added to a solution of the compound of Reference Example 5 (1.96 g, 3.71 mmol) in methylene chloride (30 ml) and the mixture was stirred at room temperature for 18 hours. Dicyclohexylurea produced during the reaction was removed by filtration and the filtrate was concentrated under reduced pressure. The residue was diluted with ethyl acetate. The ethyl acetate layer was successively washed with saturated aqueous sodium hydrogencarbonate solution and saturated aqueous sodium chloride solution, dried over magnesium sulfate and then concentrated under reduced pressure. The residue was purified by chromatography on a silica gel column using cyclohexane:ethyl acetate 4:1 as the eluant to give the desired product (2.79 g, yield 89%).

Provenance & Evidence