An Efficient Synthesis of Spiro‐oxindole Derivatives by Three‐Component Reactions in Water |
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Authors: | Abdolali Alizadeh Leila Moafi |
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Affiliation: | 1. Department of Chemistry, Tarbiat Modares University, P.O. Box 14115‐175, Tehran, Iran, (phone: +98‐21‐88006631;2. fax: +98‐21‐88006544) |
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Abstract: | An efficient synthesis of (3S)‐1,1′,2,2′,3′,4′,6′,7′‐octahydro‐9′‐nitro‐2,6′‐dioxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carbonitrile is achieved via a three‐component reaction of isatin, ethyl cyanoacetate, and 1,2,3,4,5,6‐hexahydro‐2‐(nitromethylidene)pyrimidine. The present method does not involve any hazardous organic solvents or catalysts. Also the synthesis of ethyl 6′‐amino‐1,1′,2,2′,3′,4′‐hexahydro‐9′‐nitro‐2‐oxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carboxylates in high yields, at reflux, using a catalytic amount of piperidine, is described. The structures were confirmed spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS data) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2). |
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Keywords: | Isatin Acetate, ethyl 2‐cyano‐ Pyrimidine, hexahydro‐2‐(nitromethylidene)‐ Spiro‐oxindole Oxindole Pyrido[1,2‐a]pyrimidine Multicomponent reactions |
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