Polydentate N, O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold

Stanislava E Todorova; Rusi I Rusew; Boris L Shivachev; Vanya B Kurteva

doi:10.3390/molecules28186540

Polydentate N, O-Ligands Possessing Unsymmetrical Urea Fragments Attached to a p-Cresol Scaffold

Molecules. 2023 Sep 9;28(18):6540. doi: 10.3390/molecules28186540.

Authors

Stanislava E Todorova¹, Rusi I Rusew², Boris L Shivachev², Vanya B Kurteva¹

Affiliations

¹ Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 9, 1113 Sofia, Bulgaria.
² Institute of Mineralogy and Crystallography "Acad. Ivan Kostov", Bulgarian Academy of Sciences, Acad. G. Bonchev Str., bl. 107, 1113 Sofia, Bulgaria.

Abstract

In this study, three series of polydentate N,O-ligands possessing unsymmetrical urea fragments attached to a p-cresol scaffold are obtained, namely mono- and bi-substituted open-chain aromatics, synthesised using a common experiment, as well as fused aryloxazinones. Separate protocols for the preparation of each series are developed. It is found that in the case of open-chain compounds, the reaction output is strongly dependent on both bis-amine and carbamoyl chloride substituents, while oxazinones can be effectively obtained via a common protocol. The products are characterized via 1D and 2D NMR spectra in solution and using single-crystal XRD. A preliminary study on the coordination abilities of the products performed via ITC shows that there are no substantial interactions in the pH range of 5.0-8.5 in general.

Keywords: ITC; NMR; XRD; fused aryloxazinones; polydentate N,O-ligands; unsymmetrical urea.

Grants and funding

This research received no external funding.