Patent ID: 7002036

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; and R 3 is —H, —SH, —OH, —NH 2 , —CO 2 H, —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; comprising the steps of: a.) reacting a nucleophile of the formula A—R 3 or A—(R 3 ) 2 with a compound represented by Structural Formula (II): wherein: A is —H, —Li, —MgCl, —MgBr, or —MgI, provided that A and R 3 are not each —H; R 4 is —H or a substituted or unsubstituted alkyl group; and R 1 and R 3 are as defined above; thereby forming a compound represented by Structural Formula (III): b.) reacting the compound represented by Structural Formula (III) with one or more bases, R 2 X, and a phase transfer catalyst, wherein X is a leaving group; and R 1 , R 2 , R 3 , and R 4 are as defined above; thereby forming a compound represented by Structural Formula (IV): c.) converting the compound represented by Structural Formual (IV) into a compound represented by Structural Formula (V): d.) optionally cleaving the protecting group of R 3 , thereby forming the compound represented by Structural Formula (I).