Synthesis of Acid-Degradable Poly(amidoamine)s

A new class of acid-degradable polymers with poly(amidoamine) backbones was synthesized. Reaction of N-(2-hydroxyethyl)phthalimide (1) with acetal 2a or ketal 2b provided intermediate 3, which was deprotected with NaOH and further reacted with acryloyl chloride (4) to afford monomer 5. Michael addition of piperazine monomer (6) to 5 provided the desired poly(amidoamine)s 7, which were characterized by NMR spectroscopy and GPC. The hydrolysis rate constants and half-lives of the polymers were also obtained from the hydrolysis kinetic studies. The data suggested the potential usefulness of polymer 7 in the field of polymer therapeutics and drug delivery.