THE REDUCTION OF 2-NITROFLUORENE
THE REDUCTION OF 2-NITROFLUORENE
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2-硝基芴的还原
DOI：
10.1021/ja01408a029
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发表时间：
1927
影响因子：
15
通讯作者：
J. K. Senior
中科院分区：
文献类型：
--
作者：
F. E. Cislak;I. M. Eastman;J. K. Senior
1927年9月，还原2-硝基氟溴2319混合物升温，直到所有的锌都溶解了。在还原过程中，盐酸一加入苯酚溶液就会出现深蓝绿色，并从反应混合物中分离出相当于所用偶氮化合物82%的量的2-氨基荧烯。这一结果与分析和相对分子质量一起被认为证明了有关物质的结构。有人尝试用热色乙酸处理2，2‘-偶氮氧亚甲基荧烯，使其氧化成相应的1’A荧酮，但即使用这种试剂长时间煮沸也没有改变化合物--考虑到在这种条件下大多数荧衍生物很容易转化为荧酮，这是一个不寻常的结果。在2，2‘-氮氧基-5’-呋喃还原为2-氨基荧烯的过程中，总会与胺一起形成少量白色的难溶物质，它在二甲苯重结晶时形成六方小片，在257-258℃熔化。通过改进还原方法，可以得到该化合物作为主要反应产物。用醋酸代替盐酸，在45℃以下用尽可能少的酸进行还原。该化合物最初被认为是2，2‘-肼并四茂铁(II)，这一假设与其分析和相对分子质量一致；但该物质的行为与这一假设不相容。首先，即使在苯酚溶液中，它也顽固地抵制锌和盐酸的进一步还原。在任何条件下都不能转化为2-氨基荧烯。其次，当化合物被氧化时，只产生深色的无定形产物。不可能分离出任何可鉴定为2，2‘-偶氮二茂铁(III)的物质，如果该化合物含有
Sept., 1927 REDUCTION OF 2-nitrofluorbnb 2319 mixture warmed until all the zinc had dissolved. The deep blue-green color, which appeared as soon as the hydrochloric acid was added to the phenol solution, was bleached during the reduction, and from the reaction mixture 2-aminofluorene was isolated in an amount corresponding to 82% of the azoxy compound used. This result, together with theanalysis and molecular weight, is considered to demonstrate the structure of the substance in question.Attempts were made to oxidize 2, 2'-azoxyivsfluorene to the correspond-ing i'Afluorenone by treating it with hot chromacetic acid, but even prolonged boiling with this reagent failed to alter the compound—an unusual result in view of the ease with which most fluorenederivatives are converted to fluorenones under these conditions. During the reductionof 2, 2'-azoxy5fsfluorene to 2-aminofluorene, there was always formed along with the amine a small amount of a white, difficultly soluble substance which, when recrystallized from xylene, formed hexagonal platelets, melting at 257-258 (corr.). By modifying the method of reduction, this compound could be obtained as the principal reaction product. To prepare it, acetic acid instead ofhydrochloric acid was used and the reduction was conducted below 45 with as little acid as possible. The compound was at first supposed to be 2, 2'-hydrazocTfluorene (II), a supposition with which its analysis and molecular weight agreed; but the behavior of the substance was incompatible with this assumption. In the first place, it obstinately resisted further reduction with zinc and hydrochloric acid even in phenol solution. Under no conditions could it be converted to 2-aminofluorene. Secondly, the compound, when oxidized, yielded only deeply-colored amorphous products. It was impossible to isolate any substance identifiable as 2, 2'-azobis-fluorene (III) which ought easilyto be formed if the compound had the