R 30 Reactions of 3-nitro-2-trihalomethyl-2H-chromenes with C-nucleophiles. Synthesis of 3-nitro-4-(pyrazol-4-yl)-2-trihalomethylchromanes [Electronic resource] / V. Yu. Korotaev, V. Ya. Sosnovskikh, I. B. Kutyashev, M. I. Kodess // Russian Chemical Bulletin (Translation of Izvestiya Akademii Nauk, Seriya Khimicheskaya). - 2006. - Vol. 55, № 11. - P2020-2031 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The nucleophilic addition of acetylacetone and ethyl acetoacetate at the double bond of 3-nitro-2-trihalomethyl-2H-chromenes in the presence of NaH affords 2,3,4-trisubstituted chromanes containing the ?-dicarbonyl fragment at position 4. The trans-trans configuration and the enol structure of the reaction products were confirmed by 1H NMR spectroscopy and X-ray diffraction. Treatment of these compounds with hydrazine gives the corresponding 3-nitro-4-(pyrazol-4-yl)-2-trihalomethylchromanes. The reactions of 3-nitro-2-trihalomethyl-2H-chromenes with nitromethane and nitroethane in the presence of K2CO3 produce 1,3-dinitro derivatives of the chromane series \\\\Expert2\\nbo\\Russian Chemical Bulletin\\2006, 55 (11), 2020.pdf |