TRYPTAMINES, CARBOLINES, AND RELATED COMPOUNDS .9. CYCLIZATION OF SOME NITRO- AND AZIDO-PHENYLPYRIDINES PYRIDO[1,2-B]INDAZOLE
TRYPTAMINES, CARBOLINES, AND RELATED COMPOUNDS .9. CYCLIZATION OF SOME NITRO- AND AZIDO-PHENYLPYRIDINES PYRIDO[1,2-B]INDAZOLE
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DOI：
10.1139/v61-332
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发表时间：
1961-01-01
期刊：
影响因子：
--
通讯作者：
ADAMS, KAH
中科院分区：
文献类型：
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作者：
ABRAMOVI.R;ADAMS, KAH
将2-邻硝基苯基吡啶与草酸亚铁加热，生成吡啶并[1，2-B]吲哚（III）。该化合物的结构的证据进行了讨论。类似地，加热2-邻硝基苯基吡啶碘甲烷和N-氧化物与草酸亚铁，在每种情况下，在环化之前，得到（III）的脱甲基和脱氧。在后一种情况下，也会形成微量的δ-咔啉。加热吡啶-N-氧化物与草酸亚铁是实现这些化合物脱氧的潜在通用方法。与Smith和Boyer（11）的结果相反，发现加热2-O-叠氮苯基吡啶也产生（III）。另一方面，加热作用于2-邻-叠氮苯基吡啶-N-氧化物，以低收率得到δ-咔啉和δ-咔啉-吡啶-N-氧化物的混合物。本文简要地讨论了叠氮化合物的环化反应机理和硝基化合物与草酸亚铁加热反应的机理，有利于氮烯中间体的形成，描述了2-邻硝基苯基吡啶-N-氧化物催化还原生成偶氮氧基、偶氮和肼基衍生物的过程，并讨论了这些化合物的紫外吸收光谱。它的结论是空间位阻的共面性存在于氧化偶氮和偶氮化合物，导致缺乏有效的共轭跨越N=N键。
Heating 2-o-nitrophenylpyridine with ferrous oxalate gives rise to pyrido[1,2-b]indazole (III). The evidence for the structure of this compound is discussed. Similarly, heating 2-o-nitrophenylpyridine methiodide andN-oxide with ferrous oxalate gives (III), in each case, demethylation and deoxygenation preceding the cyclization. In the latter case a minute amount of δ-carboline is also formed. Heating pyridine-N-oxides with ferrous oxalate is a potentially general method of effecting deoxygenations of these compounds. Contrary to the results of Smith and Boyer (11), it is found that heating 2-o-azidophenylpyridine also gives rise to (III). On the other hand, the action of heat on 2-o-azidophenyIpyridine-N-oxide gives a mixture of δ-carboline and δ-carboline-py-N-oxide in low yield. The mechanism of the cyclization of the azides and of the reaction taking place on heating nitro-compounds with ferrous oxalate is discussed briefly; the formation of a nitrene intermediate is favored.The catalytic reduction of 2-o-nitrophenylpyridine-N-oxide giving rise to the azoxy-, azo-, and hydrazo-derivatives is described and the ultraviolet absorption spectra of these compounds are discussed. It is concluded the steric inhibition of coplanarity exists in the azoxy- and azo-compounds leading to the lack of effective conjugation across the N=N bond.