腈钠

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提示:本条目的主题不是肼基钠

腈钠是指类化合物和离子形成的盐,这类盐被认为是反应中存在的中间体。腈钠可由腈和氨基钠、取代氨基钠或金属钠反应得到。但由于腈钠的高度不稳定性,其固体的分离特别困难。[1]

乙腈钠[编辑]

乙腈钠(NaCH2CN,Mr=63.0)被认为是一种白色固体,可由乙腈和NaN(SiMe3)2反应得到:[2]

CH3CN + 3 NaN(SiMe3)2乙醚→ NaCH2CN + HN(SiMe3)2 + 2 NaN(SiMe3)2

该反应中,乙腈只有1个氢原子被钠取代。

由于乙腈的α-H具有一定的酸性,因此与氨基钠液氨中反应,生成了一种被认为是NaCH2CN·xNH3或(CH2CN)-Na+·xNH3的产物。但当这种化合物在液氨中结晶时,产生的却是CH3C(=NH)NHNa(的钠盐)。[3]

乙腈钠可以和卤代烃反应:

NaCH2CN + RX → NaX + RCH2CN

苯乙腈钠[编辑]

苯乙腈钠(C16H13N2Na,Mr=256.3)可由苯乙腈和金属钠直接反应得到,其产物为二聚体的钠盐:[1]

3 C6H5CH2CN + 2 Na → NaCN + C6H5CH3 + C16H13N2Na

Fred等认为苯乙腈钠的结构应该是(C6H5)HC=C=N-Na(Mr=139.1)[4]

2 (C6H5)H-C=C=N-H + 2 Na → 2 (C6H5)H-C=C=N-Na
(C6H5)H-C=C=N-Na + H2 → C6H5CH3 + NaCN (副反应)

其化学性质活泼,高温下发生分解反应,产生二苯乙烯氰化钠

2 (C6H5)H-C=C=N-Na → NaCN + (C6H5)H-C=C-H(C6H5)

它和空气中的氧气反应,得到苯甲酸和氰化钠:

2 (C6H5)H-C=C=N-Na + O2 → C6H5COOH + NaCN

它和硝酸银在无水乙醇中反应,得到相应的银盐。

腈的其它金属盐[编辑]

乙腈和叔丁基锂反应,可以得到Li2CHCN。[2]

苯乙腈和钾的反应可以得到相应的钾盐,反应按如下方程式发生:[5]

2 C6H5CH2CN + 2 K → 2 C6H5HC=C=NK + H2

产物C6H5HC=C=NK对水蒸气和二氧化碳敏感,酸会将其分解,放出氰化氢。它和(C6H5)(CN)HCK有着互变异构,虽然该异构体不占主导,但能够和碘乙烷反应,产生该异构体的取代物:

(C6H5)(CN)HCK + C2H5I → (C6H5)(CN)HC(C2H5) + KI

腈的镁、铜[6]、锌盐[7]也被制得,它们和钠盐一样,都是很强的亲核试剂。这些腈的金属盐中碳氮键的三键性质之外,通过X射线分析,还有部分碳碳双键的性质。[8]

参考文献[编辑]

  1. ^ 1.0 1.1 Mary M. Rising, Tsoh-Wu Zee. SODIUM SALTS OF AROMATIC NITRILES. I. J. Am. Chem. Soc., 1928, 50 (6), pp 1699–1707. DOI: 10.1021/ja01393a028
  2. ^ 2.0 2.1 Robert West, Gerald A. Gornowicz. Polylithium compounds. IV. Polylithiation of nitriles and the preparations of trisilyl ynamines. J. Am. Chem. Soc., 1971, 93 (7), pp 1714–1720. DOI: 10.1021/ja00736a025
  3. ^ F. W. Bergstrom, Robert Agostinho. The Alkylation and Arylation of Aliphatic Nitriles in Liquid Ammonia. J. Am. Chem. Soc., 1945, 67 (12), pp 2152–2154. DOI: 10.1021/ja01228a025
  4. ^ Fred W. Upson, Robert T. Maxwell, Howard M. Parmelee. STRUCTURE OF THE SALTS OF AROMATIC NITRILES. J. Am. Chem. Soc., 1930, 52 (5), pp 1971–1975. DOI: 10.1021/ja01368a031
  5. ^ Mary M. Rising, Irving E. Muskat, Edmund W. Lowe. SALTS OF AROMATIC NITRILES. II. POTASSIUM PHENYLACETONITRILE. J. Am. Chem. Soc., 1929, 51 (1), pp 262–265. DOI: 10.1021/ja01376a033
  6. ^ Matthew Purzycki, Wang Liu, Göran Hilmersson, et al. Metalated nitriles: N- and C-coordination preferences of Li, Mg, and Cu cations. Chem. Commun., 2013,49, 4700-4702. DOI: 10.1039/C3CC41703D
  7. ^ Xun Yang, Dinesh Nath, and Fraser F. Fleming. Chemoselective Alkylations with N- and C-Metalated Nitriles. Org. Lett., 2015, 17 (19), pp 4906–4909 DOI: 10.1021/acs.orglett.5b02481
  8. ^ Fraser F. Fleming , Zhiyu Zhang , Wang Liu, et al. Metalated Nitriles: Organolithium, -magnesium, and -copper Exchange of α-Halonitriles. J. Org. Chem., 2005, 70 (6), pp 2200–2205. DOI: 10.1021/jo047877r