One-pot synthesis of dendritic polyamide III. Dendritic polyamide from 5-[3-(4-aminophenyl)propionylamino]isophthalic acid hydrochloride and 1,1,1-tris(4-carboxymethyloxyphenyl) ethane as a core molecule

One-pot synthesis of the dendritic polyamides from the Ist to the 4th generations with a very narrow molecular weight distribution was performed by condensation of 1,1,l-tris(4-carboxymethyloxyphenyl)ethane as a core molecule with aminodicarboxylic acid using the condensing agent, diphenyl(2,3-dihydro-2-thioxo-3-benzoxazolyl)phosphonate (DBOP) in N-methyl-2-pyrrolidinone (NMP). Activation and condensation reactions were each completed in 30 min. All dendritic polyamides were obtained quantitatively and fully characterized by IR and NMR spectroscopy. Number average molecular weights (M-n) of dendritic polyamides were estimated by end group analysis and each dendritic polyamide had M-n close to the calculated value. Molecular weight distribution was 1.07-1.09 as measured by GPC using THF as eluent. The degree of branching for the third generation dendritic polyamide was 0.91.