Synthesis of 1-ethyl-1H-2,1-benzothiazine 2,2-dioxide derivatives using cycloalkanecarbaldehydes and evaluation of their antimicrobial activity

 4,6-Dihydropyrano[3,2-c][2,1]benzothiazine 5,5-dioxides were synthesized via three-component interaction of 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide with active methylene nitriles and cycloalkanecarbaldehydes. The latter were also applied to obtain ammonium salts of 3,3'-(cycloalkylmethanediyl)bis(1-ethyl-1H-2,1-benzothiazin-4-ol) 2,2,2',2'-tetraoxides. The structures of the synthesized compounds were confirmed by 1H, 13C NMR as well as mass spectral and elemental analysis data. The structures of two representatives from each class of the target compounds have been additionally confirmed by single crystal X-ray diffraction study. The synthesized compounds were screened for antibacterial and antifungal activities.