Orthoamide, LXII [1]. – Mikrowellen-unterst ¨ utzte Formylierung schwach CH2-acider Verbindungen mit dem Bredereck-Simchen Reagenz – Umwandlung der Kondensationsprodukte in Heteroaromaten / Orthoamides, LXII [1]. – Microwave Assisted Formylation of Weak CH2-Acidic Compounds with the Bredereck-Simchen Reagent – Preparation of Heteroaromatic Compounds from the Condensation Products
| Autor: | Edmont V. Stoyanov, Willi Kantlehner, Wolfgang Frey, Ralf Kreß, Jochen Mezger, Gerhard Simchen, Björn Sievers |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Zeitschrift für Naturforschung B. 60:231-241 |
| ISSN: | 1865-7117 0932-0776 |
| DOI: | 10.1515/znb-2005-0218 |
| Popis: | The diformylation of the dinitriles 4 and diesters 7 with the Bredereck-Simchen reagent HC[N(CH3)2]2[OC(CH3)3] (1) under microwave irradiation give the bis-enamines 6 and 8 with dramatically reduced reaction times and improved yields compared to conventional heating. The condensation products formed can be easily converted to bis-pyrazole and bis-isoxazole derivatives 13 and 20, respectively. Methyl anthranilate reacts on prolonged heating with the orthoamide 21 to give ketene aminal 23 in low yield (8 %). Under microwave irradiation the same reagents lead to a mixture of 23 (14 %) and dihydropyrane 24 (28 %). |
| Databáze: | OpenAIRE |
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