Synthesen mit Nitrilen, LXXXVIII<sup>1</sup>; Cyan-Nitropropenide - Synthone zur Herstellung von Nitropyridinen
作者:Gerhard H. Reidlinger、Hans Junek
DOI:10.1055/s-1991-26585
日期:——
Syntheses with Nitriles, LXXXVIII;1 Cyanonitropropenides - Synthons for the Preparation of Nitropyridines Nitroacetonitrile reacts with triethyl orthoformate, orthoacetate and orthopropionate, respectively in presence of pyridine to the pyridinium salts of 1,3-dicyano-1,3-dinitro-2-propen-1-ides. With ethoxymethylenemalononitrile nitroacetonitrile yields 1,1,3-tricyano-3-nitropropenide, which can be cyclized with sodium methoxide or ethoxide to 2-alkoxy-6-amino-3-cyano-5-nitropyridines. Ether cleavage of the latter leads to 6-amino-3-cyano-5-nitro-2(1H)-pyridone, subsequent chlorination gives the corresponding 2-chloropyridine, suitable for nucleophilic substitutions. By hydrolysis of the nitrile group 6-amino-5-nitro-3-pyridinecarboxylic acid derivatives are obtained.
硝基腈与原甲酸三乙酯、原乙酸三乙酯和原丙酸三乙酯分别在吡啶存在下发生反应,生成 1,3-二氰基-1,3-二硝基-2-丙烯-1-ides 的吡啶鎓盐。硝基乙腈与乙氧基亚甲基丙二腈可生成 1,1,3-三氰基-3-硝基丙烯酰胺,后者可与甲醇钠或乙醇环化生成 2-烷氧基-6-氨基-3-氰基-5-硝基吡啶。 后者经乙醚裂解可得到 6-氨基-3-氰基-5-硝基-2(1H)-吡啶酮,随后经氯化可得到相应的 2-氯吡啶,适合亲核取代。通过水解腈基,可得到 6-氨基-5-硝基-3-吡啶甲酸衍生物。