Synthesis of polyamides by direct polycondensation with (1,2‐benzisoxazol‐3‐yl) diphenyl phosphate as a new activating agent

Abstract

AbstractA new activating agent for amide condensations, (1,2‐benzisoxazol‐3‐yl) diphenyl phosphate (1), was readily prepared in high yield by the reaction of 1,2‐benzisoxazol‐3‐ol (2) with diphenyl phosphorochloridate (3) in the presence of triethylamine in benzene. The new activating agent 1 was found to be very useful for the preparation of amides from carboxylic acids and amines. The direct polycondensation of several dicarboxylic acids with aromatic diamines using the activating agent 1 in the presence of triethylamine proceeded slowly at room temperature to produce polyamides with inherent viscosities up to 1.2 dL g−1.