Thiosemicarbazones of Acetylpyrazines: Preparation and Their Hydrophobic Properties

Some substituted acetylpyrazine derivatives were prepared as the starting materials for the subsequent synthesis of thiosemicarbazones. General synthetic approach of all newly synthesized compounds is presented. All the thiosemicarbazone derivatives of acetylpyrazines were analyzed using the reversed phase high performance liquid chromatography (RP-HPLC) method for the lipophilicity measurement. The procedure was performed under isocratic conditions with methanol as an organic modifier in the mobile phase using end-capped non-polar C18 stationary RP column. In the present study the correlation between RP-HPLC retention parameter Log K (the logarithm of capacity factor K) and various calculated Log P values is shown. The relationships between the lipophilicity and the chemical structure of the studied compounds are discussed as well.