イミダゾール 化学特性,用途語,生産方法
外観
白色～わずかにうすい黄色, 結晶～結晶性粉末
溶解性
水、エタノール及びアセトンに溶けやすい。
解説
イミダゾールは環内に窒素原子二つを含む複素環式化合物の一つ。1,3-ジアゾールの別名をもつ。グリオキサールにホルムアルデヒドとアンモニアを反応させると生成する。1858年にグリオキサールとアンモニアとの反応によって得られた。誘導体は1799年にすでに見いだされていた。誘導体には，ヒスタミン，ヒスチジン，ピロカルピンアルカロイドなどがある．
結晶性のよい固体で，融点91℃，沸点257℃。塩基性で，塩基解離指数pKb＝7.05(25℃)で，異性体のピラゾールより強く，酸と結晶性の塩をつくる。水、エタノール（エチルアルコール）、エーテルによく溶けるほか、酸に溶けて塩を生成する。コバルト(Ⅱ)イオンと反応して青紫色の沈殿を生ずるので、コバルトの検出試薬となる。混酸（硝酸と硫酸の混合物）によりニトロ化すると4-ニトロイミダゾールを生成する。
用途
有機合成原料。緩衝液調製。
イミダゾール化合物は、エポキシ樹脂の硬化剤、医農薬中間体、ウレタンの硬化触媒、銅の防錆剤、電解質などさまざまな工業分野に広く応用されています。最近ではイミダゾリウム塩が、グリーンソルベントとして注目されています。
用途
医薬品?農薬の原料、エポキシ樹脂の硬化剤原料、防錆剤、電解めっき薬として使用
化学的特性
Imidazole is a moderately strong base (pKb= 7.0), and a weak acid (pKa= 14.9). Imidazoles substituted with electron-withdrawing groups are stronger acids than imidazole itself; e.g., 4(5)-nitroimidazole has a pKa of 9.3. Imidazole is stable at 400°C, possesses considerable aromatic character, and undergoes the usual electrophilic aromatic substitution reactions. Nitration and sulfonation require, however, far more drastic conditions than the corresponding reactions with benzene. Other substitution reactions of imidazole include halogenation, hydroxymethylation, coupling with aromatic diazonium salts, and carboxylation.
来歴
Imidazole[288-32-4] was first synthesized in 1858 by Debus from ammonia and glyoxal; it was originally named glyoxalin. The name imidazole was introduced by Hantzsch. Industrial production of imidazole began in the 1950s; a wide range of derivatives is now available in industrial quantities.
主な応用
Imidazole is a versatile heterocycle used in the preparation of various biologically active compounds such as the amino acid histidine and is present in many antifungal medication. It is also used ext ensively as a corrosion inhibitor on transition metals such as copper.It is used in organic synthesis and as an antiirradiationagent.
Imidazole has been used:
in the lysis, wash and elution buffer for the purification of histidine tagged Sonic Hedgehog(shh-N) protein.
in elution buffer in stepwise gradient for the purification of histidine tagged aldo keto reductases using nickel affinity chromatography.
as a component of homogenization buffer for the purification of phagosomal compartments from dendritic cell.
製造方法
Imidazole is formed by reacting glyoxal with formaldehyde in the presence of ammonium acetate in acetic acid. The driving energy is microwave radiation. More generally, this reaction is used to produce substituted imidazoles.
Although there had been discoveries of various derivatives of imidazole in 1840, it was first reported in 1858. The synthesis process of imidazole follows the reaction between formaldehyde in ammonia and glyoxal. This process gives low yield of imidazole but it is still used to form imidazole with C-substitution (Wolkenberg et al., 2004).
定義
ChEBI: Imidazole is an imidazole tautomer which has the migrating hydrogen at position 1. It is a conjugate base of an imidazolium cation. It is a conjugate acid of an imidazolide. It is a tautomer of a 4H-imidazole. It is an important pharmacophore in drug discovery. Imidazole is used as a Karl Fischer reagent in analytical chemistry and a reagent in synthetic organic chemistry.
一般的な説明
Imidazole is a heterocyclic compound with a five-membered planar ring. It is amphoteric and highly polar. The pharmacophore of imidazole exists in bioactive compounds including amino acids, plant growth regulators and therapeutic agents.
健康ハザード
It is less toxic relative to pyrrole and otherfive-membered heterocyclic compounds ofnitrogen. Intraperitoneal administration ofimidazole caused somnolence, muscle contractions,and convulsions in mice. Theoral LD50 value in mice is in the range900 mg/kg.
火災危険
Noncombustible solid.
純化方法
Crystallise imidazole from *benzene, CCl4, CH2Cl2, EtOH, pet ether, acetone/pet ether and distilled de-ionized water. Dry it at 40o under vacuum over P2O5. Distil it at low pressure. It is also purified by sublimation or by zone melting. [Snyder et al. Org Synth Coll Vol III 471 1955, Bredereck et al. Chem Ber 97 827 1964, Caswell & Spiro J Am Chem Soc 108 6470 1986.] 15N-imidazole crystallises from *benzene [Scholes et al. J Am Chem Soc 108 1660 1986]. [Beilstein 23 II 34, 23 III/IV 564, 23/4 V 191.]
イミダゾール 上流と下流の製品情報
原材料
準備製品