Synthesis and Cycloaddition Reaction of C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium Bromides

  • Hassaneen, Hamdi M. (Department of Chemistry, Faculty of Science, University of Cairo) ;
  • Shawali, Ahmad S. (Department of Chemistry, Faculty of Science, University of Cairo) ;
  • Elwan, Nehal M. (Department of Chemistry, Faculty of Science, University of Cairo) ;
  • Abounada, Nada M. (Department of Chemistry, Faculty of Science, University of Cairo) ;
  • Algharib, Mohammed S. (Department of Chemistry, Faculty of Science, University of Cairo)
  • Published : 1992.12.01

Abstract

Coupling of naphthacylpyridinium bromide 2 [1-(2-naphthyl) ethanone-2-pyridinium bromide] with N-nitrosoacetarylamides afforded C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium bromides 3A-C. Treatment of 3A-C with base afforded the corresponding tetrazines 6A-C. Cycloaddition of nitrilimines 5A-C to N-arylmaleimides, acrylonitrile, ethyl acrylate, acrylamide, fumaronitrile, $\alpha$-cyanocinnamonitriles, ethyl $\alpha$-cyano-p-nitrocinnamates and $\alpha$-cyano-p-nitrocinnamamide afforded the corresponding cycloadducts 7-14, respectively. The cycloadducts 11-14 undergo a facile thermal elimination of hydrogen cyanide to give the corresponding pyrazoles 18-21 respectively.

Keywords