Dicyclohexylcarbodiimide → HCID 10552575, compound

Participants

Reaction Steps

To a stirred solution of 1-mercapto-1-cyclopentanecarboxylic acid (1.74 g, 4.54 mmol) in dichloromethane (50 mL) and triethylamine (0.63 mL) is added [(1-amino-(1-cyclopentyl)carbonyl]-L-tyrosine butyl ester hydrochloride (0.66 g). To this solution is added 1-hydroxy-7-azabenzotriazole (0.68 g, 4.55 mmol) and 1,3-dicyclohexylcarbodiimide (1.03 g, 4.99 mmol). The mixture is stirred for 14 hours and then the solid precipitate is removed by filtration. The organic phase is washed with a saturated solution of sodium bicarbonate (10 mL), brine (10 mL), dried over magnesium sulfate and the solvent is removed to give a clear oil. The oil is purified by flash chromatography (SiO2, hexane/ethyl acetate, 6:4) to give a clear foam. The foam is crystallized from ethyl ether to yield N-[[1-[[(1-mercapto-1-cyclopentyl)carbonyl]amino]-1-cyclopentyl]carbonyl]-L-tyrosine butyl ester, m.p. 106°-107° C.

Provenance & Evidence