5,6-二甲基苯并咪唑
外观
5,6-二甲基苯并咪唑 | |
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IUPAC名 5,6-Dimethyl-1H-benzimidazole | |
识别 | |
CAS号 | 582-60-5 ![]() |
PubChem | 675 |
ChemSpider | 655 |
SMILES |
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InChI |
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InChIKey | LJUQGASMPRMWIW-UHFFFAOYAV |
Beilstein | 116595 |
Gmelin | 279255 |
EINECS | 209-488-1 |
ChEBI | 15890 |
DrugBank | DB02591 |
KEGG | C03114 |
性质 | |
化学式 | C9H10N2 |
摩尔质量 | 146.19 g·mol−1 |
外观 | 浅黄色固体[1] |
密度 | 1.17 g·cm−3(25 °C)(漂浮法测定)[2] |
熔点 | 201—202 °C(474—475 K)[1] 205—206 °C(478—479 K)[3] |
危险性 | |
GHS危险性符号![]() | |
GHS提示词 | 警告 |
H-术语 | H302, H315, H319, H335, H412 |
P-术语 | P261, P264, P270, P271, P273, P280, P301+312, P302+352, P304+340, P305+351+338, P312, P321, P330, P332+313 |
若非注明,所有数据均出自标准状态(25 ℃,100 kPa)下。 |
5,6-二甲基苯并咪唑是一种天然的苯并咪唑衍生物,它是维生素B12中的钴的配位分子片段,[4]也是维生素B12的酸降解产物。[5]
合成
[编辑]5,6-二甲基苯并咪唑可由黄素单核苷酸经5,6-二甲基苯并咪唑合成酶生物合成。[6]
它也可以由4,5-二甲基-1,2-苯二胺和原甲酸三乙酯在碘(或三氟甲磺酸镓[3])催化下于乙腈中反应制得。[1]
结构
[编辑]5,6-二甲基苯并咪唑从常压下的水溶液中结晶,可以得到无水物晶体,无水物的α型和β型均以单斜晶系P21/c空间群结晶[7],其结构中包含晶体学独立的5,6-二甲基苯并咪唑单元,它们通过NH⋯N氢键连接,每个单元中的所有原子共平面。[2]它在0.25 GPa以上的压力下结晶,可以得到半水合物晶体C9H10N2·1⁄2H2O,X射线单晶衍射表明,该晶体以正交晶系Fddd空间群结晶,相比于无水物,半水合物分子中的NH⋯N氢键被NH⋯O键和OH⋯N键取代。[7]
当它在0.6 GPa以上的甲醇或乙醇溶液结晶时,可以得到P21/c空间群的α-C9H10N2·CH3OH或P1空间群的C9H10N2·CH3CH2OH。其中,α-C9H10N2·CH3OH加压至1.4 GPa发生相变,得到三斜晶系P1空间群的β-C9H10N2·CH3OH,这些晶体中均存在NH⋯OH⋯N氢键。[8]
反应
[编辑]5,6-二甲基苯并咪唑和溴化氰在三甲胺存在下反应,可以得到5,6-二甲基苯并咪唑-1-甲腈。[9]
它和苦味酸在水溶液中反应,可以得到黄色的苦味酸盐沉淀。[5]它和高氯酸在水溶液中反应,可以得到相应的高氯酸盐。[10]
参考文献
[编辑]- ^ 1.0 1.1 1.2 Zhang, Zhan-Hui; Li, Jian-Jiong; Gao, Yuan-Zhe; Liu, Yu-Heng. Synthesis of 2-substituted benzimidazoles by iodine-mediated condensation of orthoesters with 1,2-phenylenediamines. Journal of Heterocyclic Chemistry. 2007, 44 (6): 1509-1512. ISSN 0022-152X. doi:10.1002/jhet.5570440642.
- ^ 2.0 2.1 YoungJa Lee and W. R. Scheidt. Structure of 5,6-dimethylbenzimidazole. Acta. Cryst. 1986, (C42): 1652-1654.
- ^ 3.0 3.1 Liu, Juyan; Liu, Qian; Xu, Wei; Wang, Weilu. Expeditious and Efficient Synthesis of Benzoxazoles, Benzothiazoles, Benzimidazoles Catalyzed by Ga(OTf)3 under Solvent-Free Conditions. Chinese Journal of Chemistry. 2011, 29 (8): 1739-1744. ISSN 1001-604X. doi:10.1002/cjoc.201180310.
- ^ Barker, HA; Smyth, RD; Weissbach, H; Toohey, JI; Ladd, JN; Volcani, BE. Isolation and properties of crystalline cobamide coenzymes containing benzimidazole or 5,6-dimethylbenzimidazole. The Journal of Biological Chemistry. 1960, 235 (2): 480–8. PMID 13796809. doi:10.1016/S0021-9258(18)69550-X
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- ^ 5.0 5.1 Brink, Norman G.; Folkers, Karl. Vitamin B12. X. 5,6-Dimethylbenzimidazole, a degradation product of vitamin B12. Journal of the American Chemical Society. 1950, 72 (4442-4443). ISSN 0002-7863. doi:10.1021/ja01166a027.
- ^ 5,6-Dimethylbenzimidazole biosynthesis. MetaCyc. 2024-07-12 [2024-07-13].
- ^ 7.0 7.1 Witold Zieliński and Andrzej Katrusiak. Hydrate smaller than the anhydrate. CrystEngComm. 2015, 17 (29): 5468-5473.
- ^ Witold Zielinski and Andrzej Katrusiak. Pressure-induced preference for solvation of 5,6-dimethylbenzimidazole. CrystEngComm. 2016, (18): 3211-3215.
- ^ Kaupp, Gerd; Schmeyers, Jens; Boy, Jurgen. Quantitative Gas–Solid Reactions with ClCN and BrCN: Synthesis of Cyanamides, Cyanates, Thiocyanates, and Their Derivatives. Chemistry - A European Journal. 1998, 4 (12): 2467-2474. ISSN 0947-6539. doi:10.1002/(SICI)1521-3765(19981204)4:12<2467::AID-CHEM2467>3.0.CO;2-D.
- ^ Bayar, I.; Khedhiri, L.; Soudani, S.; Lefebvre, F.; Ferretti, V.; Ben Nasr, C. Crystal structure, quantum mechanical investigation, IR and NMR spectroscopy of two new organic perchlorates: (C6H18N3)·(ClO4)3H2O (1) and (C9H11N2)·ClO4 (2). Journal of Molecular Structure. 2018, 1161: 486-496. ISSN 0022-2860. doi:10.1016/j.molstruc.2018.02.038.