Substituted Ureas and Their Analogues Containing Cage Fragments: IV. Synthesis of Unsymmetrical N,N′-Disubstituted Bis-ureas and Urea–Thiourea Hybrids

The synthesis of new unsymmetrical aromatic bis-ureas and urea–thiourea hybrids with a hexa­methylene linker is described. The key intermediate compound in these syntheses was N-(6-aminohexyl)-N′-(3-fluorophenyl)urea salt with trifluoroacetic acid, which reacted with various halogen-substituted aryl isocyanates and isothiocyanates to give the target products in 48–80% yields. Hybrid structures containing both urea and thiourea fragments were successfully obtained through an alternative approach starting from the corresponding thiourea derivatives. Importantly, the thiourea moiety was found to be stable under acid hydrolysis conditions, which extends the scope of potential applications of these compounds.