Patent ID: 7414144

Claim:
A process for preparing a compound having the following general formula: said process comprising: (a) combining nosyl chloride with an alkyl acetate to form a first reaction mixture; (b) combining a tertiary amine with a compound of Formula I in an aromatic solvent to form a second reaction mixture, said compound of Formula I having the following general formula: (c) adding said first reaction mixture while hot with said second reaction mixture to form a third reaction mixture and heating said third reaction mixture until the reaction is complete, thereby forming said compound of Formula II; wherein: R 1 is an amino acid side chain or a functionalized amino acid side chain; R 2 is a protecting group; and R 3 and R 4 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, aryl and -NHP, wherein P is selected from the group consisting of H, alkyl, cycloalkyl, aryl and a protecting group, or R 3 and R 4 together form a cyclic structure selected from the group consisting of quinoline and isoquinoline.