1,3-Dipolar Cycloaddition Reaction of Nitrile Oxides to Isatin Imines

Abstract

<em><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: PMingLiU; mso-ansi-language: EN-US; mso-fareast-language: ZH-TW; mso-bidi-language: AR-SA;">A</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> simple and efficient one-pot route for the synthesis</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: PMingLiU; mso-ansi-language: EN-US; mso-fareast-language: ZH-TW; mso-bidi-language: AR-SA;"> of novel</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;"> spiro [indolin– oxadiazol] derivatives</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">by </span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: PMingLiU; mso-ansi-language: EN-US; mso-fareast-language: ZH-TW; mso-bidi-language: AR-SA;">1,3-dipolar cycloaddition reaction of </span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">nitrile oxides</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: PMingLiU; mso-ansi-language: EN-US; mso-fareast-language: ZH-TW; mso-bidi-language: AR-SA;"> and isatin imine under <span style="color: #1c1c1a;">classical or </span></span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">microwave irradiation</span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: PMingLiU; color: #1c1c1a; mso-ansi-language: EN-US; mso-fareast-language: ZH-TW; mso-bidi-language: AR-SA;"> conditions </span><span style="font-size: 10.0pt; font-family: 'Times New Roman','serif'; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;">is described.4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione was synthesized by cyclization of thiocarbohydrazide and acetic acid. 3-((3-methyl-5-thioxo-1,5-dihydro-4H-1,2,4-triazol-4-yl)imino)indolin-2-one was prepared by condensation of primary amine of 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-thione with isatin through a single step and 4'-(3-methyl-5-thioxo-1H-1,2,4-triazol-4(5H)-yl)- 3'-(substituted phenyl)-4'-hydro spiro[indolin-3,5'[1,2,4]oxadiazol]-2-one were afforded by the reaction of corresponding Schiff base with hydroximinoyl chloride and their derivatives under basic conditions at room temperature. The products were obtained in good yields.</span><span style="font-size: 10pt; font-family: 'Times New Roman', serif;"> Elemental analysis, IR, ¹H NMR, ¹³C NMR, and Mass spectral data confirmed the structure of newly synthesized compounds.</span></em>