Sodium Iodide → N-[N-[N-[(3S)-3-[[(t-Butyloxy)carbonyl]amino]-2-oxo-5-methylhexyl]-L-leucyl]-L-valyl]-L-phenyl-alanine, methyl ester

Participants

Reaction Steps

A mixture of 856 mg (2 mmol) of L-leucyl-L-valyl-L-phenylalanine, methyl ester, hydrochloride, 100 mg (0.668 mmol) of sodium iodide, and 352 mg (4.2 mmol) of sodium bicarbonate in 3 ml of dimethylformamide was treated with 580 mg (2.2 mmol) of [(t-butyloxy)carbonyl]-L-leucine chloromethyl ketone dissolved in 2 ml of dimethylformamide, and the reaction was stirred at room temperature under a flow of nitrogen overnight. The reaction was then diluted with a mixture of 80 ml of ethyl acetate and 20 ml of ether, then washed with 20 ml portions of water (2×), 5% aqueous sodium bisulfite, water (2×), brine, dried (magnesium sulfate), and concentrated in vacuo to afford 1.1 g of crude product. Flash chromatography on 30 g of LPS-1 silica gel eluting with a 5:1 mixture of petroleum ether:acetone afforded 680 mg of partially purified product. Recrystallization from acetone:petroleum ether afforded 490 mg of the title compound, melting point 127°-129° C.

Provenance & Evidence