Patent ID: 7038073

Claim:
A method of preparing a compound represented by Structural Formula (I): or a salt thereof; wherein: R 1 is —H or a substituted or unsubstituted alkyl group; R 2 is a substituted or unsubstituted alkyl group; R 3 is —H, —(CH 2 ) x S(CH 2 ) y H, —(CH 2 ) x O(CH 2 ) y H, —(CH 2 ) x NH(CH 2 ) y H, —COOH, —CONH 2 , —NHC(NH)NH 2 , a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloaliphatic group, or a substituted or unsubstituted aromatic group, wherein R 3 optionally comprises a protecting group; x is an integer from 0–12; and y is an integer from 0–4; comprising the steps of: a.) reacting the compound represented by Structural Formula (III): wherein: L is a bond, a sulfoxide (—S(O)—), or a sulfone (—S(O)(O)—); and R 4 is a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group; with a nucleophile of the formula A-R 3 , wherein A is —H, —Li, —MgCl, —MgBr, or —MgI, provided that A and R 3 are not each —H, and R 1 , R 2 and R 3 are as defined above; thereby forming a compound represented by Structural Formula (IV): b.) cleaving L-R 4 and optionally the protecting group of R 3 from the compound represented by Structural Formula (IV), thereby forming the compound represented by Structural Formula (I).