An unexpected tautomer: synthesis and crystal structure of N-[6-amino-4-(methyl-sulfan-yl)-1,2-di-hydro-1,3,5-triazin-2-yl-idene]benzenesulfonamide

Reham A Mohamed-Ezzat; Galal H Elgemeie; Peter G Jones

doi:10.1107/S2056989023011076

An unexpected tautomer: synthesis and crystal structure of N-[6-amino-4-(methyl-sulfan-yl)-1,2-di-hydro-1,3,5-triazin-2-yl-idene]benzenesulfonamide

Acta Crystallogr E Crystallogr Commun. 2024 Jan 9;80(Pt 2):120-124. doi: 10.1107/S2056989023011076. eCollection 2024 Feb 1.

Authors

Reham A Mohamed-Ezzat¹, Galal H Elgemeie², Peter G Jones³

Affiliations

¹ Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Institute, National Research Centre, Cairo, Egypt.
² Chemistry Department, Faculty of Science, Helwan University, Cairo, Egypt.
³ Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany.

Abstract

The title compound, C₁₀H₁₁N₅O₂S₂, consists of an unexpected tautomer with a protonated nitro-gen atom in the triazine ring and a formal exocyclic double bond C=N to the sulfonamide moiety. The ring angles at the unsubstituted nitro-gen atoms are narrow, at 115.57 (12) and 115.19 (12)°, respectively, whereas the angle at the carbon atom between these N atoms is very wide, 127.97 (13)°. The inter-planar angle between the two rings is 79.56 (5)°. The mol-ecules are linked by three classical hydrogen bonds, forming a ribbon structure. There are also unusual linkages involving three short contacts (< 3 Å) from a sulfonamide oxygen atom to the C-NH-C part of a triazine ring.

Keywords: 1,3,5-triazine; benzenesulfonamide; crystal structure; hydrogen bonds.