1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → HCID 67771702, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of N-(3,5-dimethylbenzoyl)-N-methyl-2-methyl-3-[4-(3-thienyl)phenyl]alanine (135 mg, 0.33 mmol) in DMF are successively added tryptophan methyl ester hydrochloride (110 ml, 0.43 mmol), 1-Hydroxybenzotriazole (58 mg, 0.43 mmol), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (5.46M solution) 79μ, 0.43 mmol) at 0° C. under nitrogen atomosphere. The reaction mixture is allowed to stir at 0° C. for 2 h, then at room temperature overnight. The mixture is diluted with ethyl acetate and washed with 10% citric acid twice. The organic layer is dried over magnesium sulfate and concentrated in vacuo. The residue is chromatographed on silica with hexane/ethyl acetate (1:1) to give (D,L)-isomer (55 mg) and (L,L)-isomer (80 mg: including 15% of (D,L)-isomer) (total 67%) of 3-[4-(3-thienyl)phenyl]alanyl-tryptophan methyl ester. Hydrolysis of (D,L)-isomer (55 mg, 0.09 mmol) with lithium hydroxide hydrate (6 mg, 0.14 mmol) affords N-(3,5-Dimethylbenzoyl)-N-methyl-(D)-2-methyl-3-[4-(3-thienyl)phenyl)-alanyl-(L)-tryptophan FAB-MS m/e 592 (M-H)+.

Provenance & Evidence