Synthesis and structure of novel 1lambda4,2,6-thiadiazines

Area of Science:

• Organic Chemistry
• Heterocyclic Chemistry
• Sulfur Chemistry

Background:

• Sulfodiimines are established precursors for sulfur-nitrogen heterocycles.
• The synthesis of novel thiadiazine derivatives remains an active area of research.

Purpose of the Study:

• To synthesize and characterize new 1lambda(4),2,6-thiadiazine-3-ones.
• To explore the reactivity of these novel heterocycles with various electrophiles.

Main Methods:

• Addition-condensation reactions of S,S-disubstituted sulfodiimines with activated carbonyl substrates.
• S-Debenzylation using electrophiles like TMSCl, Alk(3)O(+)BF(4)(-), Tos(2)O, and Mes(2)O.
• Structure elucidation using spectroscopic methods, revealing NH/CH tautomers and a tetrahedral sulfur center.

Main Results:

• Synthesis of new 1lambda(6),2,6-thiadiazine-3-ones and 1lambda(4),2,6-thiadiazine-3-ones.
• Identification of NH/CH tautomers and a tetrahedral asymmetric sulfur atom within the thiadiazine ring.
• Selective alkylation leading to 3-alkoxy-1lambda(4)-2,6-thiadiazines and N-2-alkyl isomers.
• Mesylation followed by aminolysis yielded desired heterocycles.

Conclusions:

• Novel 1lambda(4),2,6-thiadiazine-3-ones were successfully synthesized and characterized.
• The study details the structural features and reactivity patterns of these compounds.
• The developed synthetic routes offer access to previously inaccessible sulfur-nitrogen heterocycles.