4156-16-5

white to off-white crystalline powder

Peptide-bond former.

Crystallise the reagent from diethyl ether or ethyl acetate/pet ether. [Lamas et al. J Am Chem Soc 108 5543 1986.] It is best purified by dissolving in excess of aqueous N HCl and precipitating with Me2CO to give a white fluffy solid. [Woodward et al. Tetrahedron 22 Suppl 8 321 1966, Fieser & Fieser Reagents for Organic Synthesis 1 385, 2 198.]