N,N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack adducts with 1,3,5-triazine compounds as efficient catalysts for the transesterification of β-ketoesters |
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Authors: | Govardhan Duguta Satish Kumar Mukka Bhooshan Muddam Yadaiah Chityala |
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Institution: | 1. Department of Chemistry, Osmania University, Hyderabad, India;2. P. G. College, Osmania University, Mirzapur (B), India;3. Department of Chemistry, M.V.S.R. Engineering College, Hyderabad, India |
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Abstract: | AbstractN, N’-dimethyl formamide (DMF) mediated Vilsmeier–Haack (VH) adducts with 1,3,5-triazine compunds such as trichloroisocyanuric acid (TCCA) and trichlorotriazine (TCTA) were prepared by replacing classical oxy chlorides POCl3, and SOCl2, which were explored as efficient catalysts for the transesterification of β-ketoesters. The prepared (TCCA/DMF) and (TCTA/DMF) adducts improved greenery of the classical Vilsmeier–Haack reagents (POCl3/DMF), and (SOCl2/DMF), and demonstrated their better efficient catalytic ativity. Reaction times were in the range: 3.5 to 6.5?hr (SOCl2/DMF); 2.8–5.2?hr (POCl3/DMF); 2.5–5.2?hr (TCCA/DMF) and 2.5–5.0?hr (TCTA/DMF) catalytic systems. Ultrasonically (US) assisted protocols with these reagents further reduced the reaction times (two to three times), while microwave assisted (MW) protocols with these reagents were much more effective. The reactions could be completed in only few seconds (less than a minute) in MWassisted protocols as compared to US assited reactions, followed by good product yields. |
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Keywords: | β-Ketoesters oxychloride/DMF adducts rate enhancements symmetric triazine/DMF adducts transesterification |
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