Patent ID: 7331920

Claim:
A method for preparing a glycopeptide comprising the steps of: (a) selecting a protected glycopeptide of the formula A 1 -A 2 -A 3 -A 4 -A 5 -A 6 -A 7 , wherein the groups A 1 to A 7 comprise the heptapeptide structure of naturally occurring vancomycin; at least A 4 is linked to a glycosidic group which has a hexose residue linked to A 4 ; and said protected glycopeptide has a free primary hydroxyl group only at the 6-position of said hexose residue; (b) contacting said protected glycopeptide with a compound ArSO 2 G in which Ar is an aryl group and G is a leaving group under conditions effective to allow reaction of said free primary hydroxyl group to form a glycopeptide sulfonate ester; and (c) contacting said glycopeptide sulfonate ester with a nucleophile under conditions effective to allow displacement of a sulfonate group to produce a substituted glycopeptide.