SYNTHESIS, OPTIMIZATION, AND SPECTROSCOPIC CHARACTERIZATION OF A NOVEL SYMMETRICAL AROMATIC BIS-CARBAMATE: N,N′-HEXAMETHYLENE BIS(ORTHO-CRESOLYL CARBAMATE)

Abstract

Carbamate derivatives constitute an important class of organic compounds owing to their extensive applications in medicinal chemistry, agrochemistry, polymer science, and advanced functional materials. The development of new aromatic bis-carbamates with high synthetic efficiency and well-defined structures remains an important challenge in modern organic synthesis. In the present work, a previously unreported symmetrical aromatic bis-carbamate, N,N′-hexamethylene bis(ortho-cresolyl carbamate), was synthesized via the reaction of ortho-cresol with hexamethylene diisocyanate in the presence of triethylamine using dimethylformamide as the reaction medium. The influence of reaction temperature, reaction time, and solvent nature on the synthesis efficiency was systematically investigated. The optimum reaction conditions were established at 35–40 °C for 3.0–3.5 h in DMF, providing the target compound in an excellent isolated yield of 97.6\%. The synthesized bis-carbamate was characterized by elemental analysis together with FTIR, ¹H NMR, and ¹³C NMR spectroscopy. The spectroscopic data unequivocally confirmed the formation of the urethane functional groups, the complete consumption of the isocyanate precursor, and the highly symmetrical molecular structure of the target compound. The developed synthetic methodology provides a simple, efficient, and reproducible route for the preparation of aromatic bis-carbamates and may serve as a versatile platform for the synthesis of structurally related carbamate derivatives with potential applications in polymer chemistry, functional materials, and biologically active compounds. To the best of our knowledge, this work represents the first report on the synthesis and comprehensive spectroscopic characterization of N,N′-hexamethylene bis(ortho-cresolyl carbamate), thereby expanding the structural diversity of aromatic bis-carbamates and providing a promising molecular scaffold for future functional and biological studies.