Lega D. Synthesis and biological activity of condensed 2-amino-4H-pyrans based on 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide

The work is devoted to the complex investigation of three-component interaction of 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide with active methylene nitriles and various classes of carbonyl compounds aiming to synthesize new promising biologically active compounds, namely 2-amino-4H-pyrans fused with 1-ethyl-1H-2,1-benzothiazine core. Compounds comprising new heterocyclic systems 2-amino-4,6-dihydropyrano[3,2-с][2,1]benzothiazine 5,5-dioxide and spiro[(2-amino-4,6-dihydropyrano[3,2-c][2,1]benzothiazine 5,5-dioxide)-4,3?-(indolin-2?-one)] were obtained. The new experimental data, related to direction of the three-component interaction were found out. The latter were used to complete the known mechanism of three-component reactions of enolnucleophiles with active methylene nitriles and carbonyl compounds. Pharmacological screening of the obtained compounds revealed a promising route to search among them new efficient substances with analgesic and anti-inflammatory activities.