Bioisosteric Replacement in the Search for Biologically Active Compounds: Design, Synthesis and Anti-Inflammatory Activity of Novel [1,2,4]triazino[2,3-c]quinazolines.

Designing novel biologically active compounds with anti-inflammatory properties based on condensed quinazolines is a significant area of interest in modern medicinal chemistry. In the present study, we describe the development of promising new bioactive molecules through the bioisosteric replacement of a carbon atom with a sulfur atom in anti-inflammatory agents, specifically 3-methyl-2-oxo-2-[1,2,4]triazino[2,3-]quinazolin-6-yl)butanoate. Design and synthetic studies have led to the series of previously unknown substituted 2-[((3-R-2-oxo-2-[1,2,4]triazino[2,3-]quinazolin-6-yl)methyl)thio]carboxylic acids and their esters.