Synthesis of poly(ethylene glycol methyl ether)-b-poly(ethylenimine) and its derivatives containing thymine and amino acids as pendants

Abstract

Poly(ethylene glycol methyl ether)tosylate was prepared and used to initiate the polymerization of 2-methyl-2-oxazoline. The resulting poly(ethylene glycol methyl ether)-b-poly( N -acetyl ethylenimine) was hydrolyzed and neutralized to give poly(ethylene glycol methyl ether)-b-poly(ethyl-enimine) (PEO–PEI). 2-(thymin-1-yl)propionic acid, N -Cbz-alanine, N -Cbz-proline, N -Cbz-O- t -Bu-serine. and N -FMOC-proline were grafted onto the PEO–PEI copolymer; attempts were then made to remove the Cbz and FMOC protecting groups.