Pentafluorophenyl ester activation for the preparation of N,N'-diaroylhydrazines

Article abstract of DOI:10.1016/S0040-4020(97)00149-X

Procedures are reported for the preparation of N,N'-diaroylhydrazines using pentafluorophenyl (Pfp) ester activation of aryl carboxylic acids. Mild conditions which avoid intermediate protection of ring substituents, allows the synthesis of both symmetrical and unsymmetrical diaroylhydrazines in high yields. The recent discovery of potent HIV-1 integrase inhibition by N,N'-bis-salicylhydrazine (1) highlights the potential importance of this class of compounds. The stability of pre-activated Pfp ester intermediates and the facility with which N,N'-diaroylhydrazines can be synthesized using this procedure (stirring at room temperature in DMF) may make the method particularly attractive for synthesis of hydrazide libraries.