Polymerizable dendrimers .2. Mono-methacryl modified dendrimers containing up to 16 ester functions via stepwise condensations of L-aspartic acids

A convergent synthesis of polymerizable dendrimers consisting of one methacrylic function combined with an alkylene spacer and several condensed L-aspartic acid components is described. The highly functionalized monomers were prepared from N-methacryloyl amino undecanoic acid (9) via condensation with free amino groups of L-aspartic acid dimethyl ester (2), alpha,beta-bis-(L-dimethoxyaspartyl)-L-aspartic acid hydrobromide (4) and alpha,beta-bis-(L-aspartyl-alpha,beta-bis-(L-dimethoxyaspartyl))-L-aspartic acid hydrobromide (6). The number of ester groups increased from 2 to 4 and 8, up to 16, depending on the dendritic generation of the condensed amino acids. The monomers were homopolymerized and copolymerized with styrene through a free radical mechanism.