Direct synthesis of polyamides by N-acyl phosphoramidites

A variety of N-acyl phosphoramidites were prepared from chlorophosphites and amide derivatives, and their structures were determined with the aid of ¹H-, ¹³C-, and ³¹P-NMR, and IR spectroscopies. These phosphoramidites were employed in direct polycondensation reaction of dicarboxylic acids and diamines under various conditions resulting in polyamides with inherent viscosities of 0.1 to 1.13. The best results were obtained when aliphatic dicarboxylic acids and aromatic diamines were condensed by 2-(N-methylacetamido)-1,3,2-dioxaphospholane in nitriles.