Stuclies on 4-Thiazolidinones. Preparation and Antimicrobial Activity of α-Phenyl-2-(2/, 5/-dihydroxy-3'-bromophenyl)-3'-aryl-5'-carboxymethy 1-4-thiazolidinones, α -Methyl2-(2'-hydroxy-3'/-nitro-5',-,-benzyl) .. 3'-aryl-5'-H/carboxymethyl4-thiazolidinones and α -Methyl-2-(2'/-hydroxy-3'/-nitro-5'/-chlorophenyl)-3-aryl-5-H/carboxymethyl-4-thiazoliGlinones