15N‐NMR. Studies of Aminopyridines, Aminopyrimidines and of Some Diazine N‐Oxides
15N‐NMR. Studies of Aminopyridines, Aminopyrimidines and of Some Diazine N‐Oxides
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15N-NMR。氨基吡啶、氨基嘧啶和一些二嗪氮氧化物的研究
DOI：
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发表时间：
1980
期刊：
影响因子：
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通讯作者：
I. Kompiš
中科院分区：
文献类型：
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作者：
Werner Städeli;W. V. Philipsborn;A. Wick;I. Kompiš
15 n-nmr。在中性和酸性介质中研究了单、二氨基嘧啶和单、二、三氨基嘧啶的光谱，包括甲氧苄啶和其他二氢叶酸还原酶抑制剂。给出了完整的化学移位作业。从氨基和烷基的β-、χ-和δ-取代效应的角度讨论了环氮位移。测定了TFA-和fso3h溶液中的质子化状态以及环和氨基n原子15n位移的质子化增量。氨基吡啶环n原子上的氨基取代基效应（Δδ(15N)）与氨基苯中相应的Δδ(13C)值呈线性相关，同样，氨基吡啶中的Δδ(15N)值与氨基吡啶中的Δδ(13C)值也呈线性相关。15N-NMR的分配。通过与14N-NMR的比较，得到了嘧啶n -氧化物、吡嗪n -氧化物和吡嗪n -氧化物的光谱。数据，并借助Yb(food)3诱导位移。报道了氨基吡啶和氨基嘧啶的单键15N， 1h偶联常数，并从nh2基团与环体系的共轭相互作用的角度进行了讨论。
15N-NMR. spectra of mono- and diaminopyridines, and mono-, di- and triaminopyrimidines including trimethoprim and other dihydrofolate reductase inhibitors have been studied in neutral and acidic media. Complete chemical shift assignments are given. Ring-nitrogen shifts are discussed in terms of β-, χ- and δ-substituent effects of amino and alkyl groups. Protonation states in TFA- and FSO3H-solution and protonation increments for the 15N-shifts of ring and amino N-atoms are determined. A linear correlation is observed between amino substituent effects (Δδ(15N)) on the ring N-atom in aminopyridines and corresponding Δδ (13C) values in aminobenzenes and, similarly, between Δδ(15N) values in aminopyrimidines and Δδ(13C) values in aminopyridines. Assignment of the 15N-NMR. spectra of pyrimidine N-oxides, pyrazine N-oxides and pyridazine N-oxides is achieved by comparison with 14N-NMR. data and with the aid of Yb(fod)3-induced shifts. One-bond 15N, 1H-coupling constants are reported for aminopyridines and aminopyrimidines and discussed in terms of conjugative interaction between NH2-group and ring system.