Abstract: The condensation between benzylamine and isonicotinic acid leading to N-benzylamide-4-pyridinecarboxylic acid is
the first stage in the synthesis of the modern antiviral Enisamium iodide (N-methyl-4-benzylcarbomidepyridinium iodide), also
known on the domestic market as Amizon. The condensation product yield and quality have a strong bearing on a successful
synthesis of the drug and on technical-economic indicators of the manufacture of the active pharmaceutical ingredient Enisamium
iodide. Thermoanalytical studies were done for N-benzylamide-4-pyridinecarboxylic acid by differential scanning calorimetry
(DSC) and thermogravimetric analysis (TGA), and the relationship between the conversion degree of isonicotinic acid and
benzylamide quantity was examined. The product yield depending on the solvent mass ratio upon crystallization of N-benzylamide4-pyridinecarboxylic acid from toluene was shown. The findings can be used in organizing the manufacture of the active
pharmaceutical ingredient Enisamium iodide.
Index terms: N benzylamide-4-pyridinecarboxylic acid, N-methyl-4-benzylcarbomidepyridinium iodide, Enisamium iodide, condensation.