Triethylamine → Amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide

Participants

Reaction Conditions

Reaction Steps

22.9 mg of L-N-[(2R or S)-5-ethylsulfonyl-2-(1-naphthylmethyl)pentanoyl]norleucine was dissolved in 0.2 ml of dry DMF, and 6.23 mg of triethylamine and 16.9 mg of DPPA were added under stirring at -15° C. Then, 26.8 mg of (2RS,4S,5S)-5-amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide monohydrochloride was dissolved in 0.1 ml of dry DMF and neutralized with 8.79 mg of triethylamine. This dry DMF solution was added to the previous reaction solution, and the mixture was stirred at -10° C. for one hour and at 5° C. overnight. The reaction solution was diluted with 20 ml of ethyl acetate, and the ethyl acetate layer was washed with water and with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate. Then, the solvent was distilled off, and the residue thereby obtained was purified by silica gel column chromatography (chloroform/methanol=75/1) to obtain 18.2 mg of (2RS,4 S,5S)-5-{L-N-[(2R or S)-5-ethylsulfonyl-2-(1-naphthylmethyl)pentanoyl]norleucyl}-amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide as colorless solid.

Provenance & Evidence