Synthesis of N₈-macrocyclic ligands by polyphosphoric acid-catalysed condensation <span style="font-size:12.0pt;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-IN;mso-fareast-language: EN-IN;mso-bidi-language:AR-SA" lang="EN-IN">of trimethoprim with amino acids</span>

Abstract

<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">Trimethoprim [2,4-diamino-5-(3', 4',5'-trimethoxybenzyl) pyrimidine] reacts with amino acids to give colourless N₈-macrocyclic compounds by the polyphosphoric acid-catalysed condensation. The products contain a cross conjugated macrocyclic system of a novel type, related to some extent to azoporphins. The condensation proceeds to give products which, in certain instances, are not readily attainable by conventional condensation techniques.</span>