“…The synthesis used in this study is a practical procedure that permits us to prepare very beautiful crystalline dyes 2 – 4 (R1 = H, phenyl) from Zincke salts ( DNP) 2,4‐dinitrophenyl 1 and secondary amines diethylamine or pyrrolidine according to Scheme . Pyridinium salts are a versatile class of compounds used as phase transfer catalysts,16 initiators of cationic polymerization,17 wide range antimicrobials,18 enzyme inhibitors,19, 20 acylating agents,21 dyes, and cationic surfactants 22. Their chiral representatives, that is, pyridinium salts containing a chiral auxiliary group linked to the ring nitrogen, have been largely used as starting materials in asymmetric synthesis to obtain substituted chiral dihydropyridines,23 tetrahydropyridines,24 piperidines,25 and nitrogenated complex compounds such as natural alkaloids26 and synthetic candidates for drugs 20…”