Other Six-Membered Rings With Four or Five Nitrogen, Oxygen, or Sulfur

The current chapter is an amalgamation of the synthesis of 1,2,4,6-thiatriazines, 1,4,3,5-oxathiadiazines, 1,2,3,5-oxathiadiazines, 1,2,4,5-tetroxanes, 1,2,4,5-tetrathianes and 1,2,4,5-tetrazine and their derivatives. The fundamental significance and application of multi-heteroatom scaffolds in chemistry have been reported. Synthesis and reactions of 1,2,4,5-tetrazine derivatives involving mainly Diels Alder reactions, oxidation, and cyclization strategies have also been demonstrated. Sulfonamides synthons for the synthesis of thiatriazine via cyclization have also been discussed. Lastly, temozolomide, a naturally occurring prodrug used for the treatment of malignant brain tumors has been elaborated in this article.