Protonation sites and hydrogen bonding in mono-hydrobromide salts of two N,4-diheteroaryl 2-aminothiazoles

Abstract The synthesis and structural characterization of N -(6-methoxypyridin-3-yl)-4-(pyridin-2-yl)thiazol-2-amine mono-hydrobromide monohydrate ( 3 ) -(6-methoxypyridin-3-yl)-4-(pyrazin-2-yl)thiazol-2-amine 0.35 methanol solvate 4 are reported. crystal structures (monoclinic, space group P 2 1 / n , Z = 4) group, C 2/ c 8) feature ,4-diheteroaryl 2-aminothiazoles showing similar molecular conformations but different sites protonation thus distinctly intermolecular hydrogen bonding patterns. In amine –H⋯Br − + pyridine –H⋯O water O bonds link protonated molecules bromide anions into a three-dimensional hydrogen-bonded network, whereas methoxypyridine –H⋯N pyrazine result in zigzag chains .