L-Malic Acid → 2-((s)-2-((r)-3-Methyl-1-((s)-3-phenyl-2-(pyrazine-2-carboxamido)propanamido)butyl)-5-oxo-1,3,2-dioxaborolan-4-yl)acetic acid

Participants

Reaction Steps

A mixture of N,N′,N″-(boroxin-2,4,6-triyltris{[(1R)-3-methylbutane-1,1-diyl]imino[(2S)-1-oxo-3-phenylpropane-1,2-diyl]})tripyrazine-2-carboxamide (0.500 g, 0.455 mmol) and L-malic acid (213.6 mg, 0.55 mmol) were mixed in THF (5 mL). The mixture was heated to form a solution. The solution was cooled uncontrolled until the internal temperature was about 25° C. White solid precipitated out and the resultant slurry was agitated at ambient temperature for 1 h. The slurry was filtered to collect solid 2-((S)-2-((R)-3-methyl-1-((S)-3-phenyl-2-(pyrazine-2-carboxamido)propanamido)butyl)-5-oxo-1,3,2-dioxaborolan-4-yl)acetic acid (0.625 g, 95%). MS (m/z) in CH3CN: [M+H] calculated for C23H28BN4O7, 483.2051. found, 483.2.

Provenance & Evidence