Synthesis and antibacterial activity of some new 1,8-naphthyridinyl-4-thiazolidinones

Ethyl 1,8-napthyridin-2-one-3-carboxylate 1 on reaction with hydrazine hydr ate furnishes 1,8-naphthyridin-2-one-3-carboxylic acid hydrazide 2, which o n treatment with different aromatic aldehydes yields 1,8-naphthyridin-2-one -3-carboxylic acid arylidene-hydrazides 3. Cyclocondensation of 3 with merc aptoacetic acid in DMF in the presence of anhyd. ZnCl2 affords 2-aryl-3-(1, 8-naphthyridin-2-one-3-carbonylamino)-4-thiazolidinones 4. Structure elucid ation of the products has been deduced on the basis of elemental analyses, IR, H-1 NMR and MS data. Compounds 4 have been screened for their antibacte rial activity against both grampositive and gram-negative bacteria.