SYNTHESIS OF SOME NEW SPIROHETEROCYCLIC PYRYLIUM-SALTS RELATED TO 1-OXA-4-THIASPIRO[4.4] NONAN-2-ONE AND OR [4.5]DECAN-2-ONE AS ANTIMICROBIAL AGENTS/

1-Oxa-4-thiaspiro[4,4]nonan-2-one (1a) and/or 1-oxa-4-thiaspiro[4.5] d ecan-2-one (1b) were reacted with aniline and/or p-chloroaniline to af ford the corresponding spirothiazolidinones (2a-d). Reaction of 2a-d w ith chalcones gave ylbenzyl)-4-aryl-1-thia-4-azaspiro[4.4]nonan-3-one and ylbenzyl)-4-aryl-1-thia-4-azaspiro[4.5]decan-3-one (2a-p) respecti vely. Compounds 3a-p were reacted with acetic anhydride and perchloric acid to yield the spiropyrano[2,3-d]thiazol[4]ium perchlorate derivat ives 4a-p. The structures of the synthesized compounds were elucidated by elemental and spectroscopic (IR and H-1-NMR) analysis. All the pre pared compounds were tested for their antimicrobial activities in comp arison with tetracyclic as a reference compound.