Triethylamine → HCID 10530305, compound

Participants

Reaction Steps

A mixture of N-[[1-[(2-(S)-mercapto-3-methyl-1-oxobutyl)amino]-1-cyclopentyl]-carbonyl]-L-tyrosine ethyl ester (0.32 g, 0.73 mmole), cyclopentanecarboxylic acid (0.083 g, 0.73 mmole), dicyclohexylcarbodiimide (0.15 g, 0.73 mmole), 1-hydroxy-7-azabenzotriazole (0.10 g, 0.73 mmole), and triethylamine (0.10 ml, 0.73 mmole) in methylene chloride (30 ml) is stirred overnight at room temperature. The resulting mixture is filtered, washed with sodium bicarbonate solution, then with brine, dried over magnesium sulfate and evaporated to dryness. The residue is purified by flash chromatography on silica gel eluting with hexane ethyl acetate. The pure fractions are concentrated and the residue is crystallized from diethyl ether to yield N-[[1-[(2-(S)-cyclopentylcarbonylmercapto-3-methyl- 1-oxobutyl)amino]-1-cyclopentyl]-carbonyl]-L-tyrosine ethyl ester, m.p. 130°-131° C., the compound of formula Ill wherein R4 is 4-hydroxyphenyl, R2 is ethyl, R3 is cyclopentylcarbonyl, and R4 is isopropyl.

Provenance & Evidence