General Synthesis of 1-Aryl-6-azaisocytosines and Their Utilization for the Preparation of Related Condensed 1,2,4-Triazines

Molecules. 2019 Oct 1;24(19):3558. doi: 10.3390/molecules24193558.

Abstract

A simple general synthesis of 1-aryl-6-azaisocytosine-5-carbonitriles 4 is described. This method is based on coupling diazonium salts with cyanoacetylcyanamide 2 and then cyclization of the formed 2-arylhydrazono-2-cyanoacetylcyanamides 3. The 6-azaisocytosines 4 were studied with respect to tautomeric equilibrium and the transformation of functional groups, and used in the synthesis of the condensed heterocyclic compounds: Purine isosteric imidazo[2,1-c]-[1,2,4]triazine 8 and the 1,2,4-triazino[2,3-a]quinazolines 9-12.

Keywords: 1,2,4-triazine; 1-aryl-6-azaisocytosine; condensed 1,2,4-triazine; cyclization of arylhydrazones; fused azaisocytosines.

MeSH terms

  • Cyclization
  • Cytosine / chemistry*
  • Molecular Structure
  • Pyrimidines / chemical synthesis*
  • Pyrimidines / chemistry
  • Triazines / chemical synthesis*
  • Triazines / chemistry

Substances

  • Pyrimidines
  • Triazines
  • 1,2,4-triazine
  • Cytosine