Synthesis of 4-thiazolidinone and 2-azetidinone derivatives of 2-trifluoromethyl- <span style="font-size:12.0pt;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";mso-ansi-language:EN-IN;mso-fareast-language: EN-IN;mso-bidi-language:AR-SA" lang="EN-IN">1,8-naphthyridine as antibacterial agents</span>

Abstract

Ethyl 2-trifluoromethyl- 1,8-naphthyridine-3-carboxylate <b style="mso-bidi-font-weight:normal">3</b> has been synthesized by the condensation of 2- aminonicotinaldehyde <b style="mso-bidi-font-weight:normal">1</b> with ethyl trifluoroacetoacetate <b style="mso-bidi-font-weight:normal">2</b> and subjected to hydrazinolysis with refluxing hydrazine hydrate to give 2-trilluoromethyl-1,8-naphth yridine-3-carboxylic acid hydrazide <b style="mso-bidi-font-weight:normal">4</b>. The acid hydrazide <b style="mso-bidi-font-weight:normal">4</b> reacts with aromatic aldehydes to yield the corresponding 2-trilluoromethyl -1,8-naphthyridine-3-carboxylic acid arylidenehydrazides <b style="mso-bidi-font-weight:normal">5</b>. Cyclocondensation of <b style="mso-bidi-font-weight:normal">5</b> with mercaptoacetic acid in DMF in the presence of anhyd. ZnCl₂ affords 2-aryl-3-(2-

<span style="font-size:12.0pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-in;mso-fareast-language:="" en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">trifluoromethyl-1,8-naphthyridine-3-carbonylalllino)-4-thiazolidinones <b style="mso-bidi-font-weight:normal">6</b>. On the other hand, cycloaddition of chloroacetyl chloride to <b style="mso-bidi-font-weight:normal">5</b> in dioxane in the presence of Et₃N gives 4-aryl-3-chloro-1-(2-trilluoromethyl-1,8 -naphthyridine-3-carbonylamino)-2-azetidinones <b style="mso-bidi-font-weight: normal">7</b>. These compounds have been characterized on the basis of elemental analysis. IR, ¹H NMR and MS. All the products have been evaluated for antibacterial activity.</span>