Silica sulfuric acid/NaNO2 as a novel heterogeneous system for production of thionitrites and disulfides under mild conditions
在温和的条件下以硅磺酸的亚硝酸钠作为一种新型的非均相体系制备硫代亚硝酸盐和二硫化物
Mohammad Ali Zolfigol
Department of Chemistry, College of Science, Bu-Ali Sina University, P.O. Box 4135, Hamadan 65174, Iran
Received 9 April 2001; revised 23 August 2001; accepted 13 September 2001
穆罕默德·阿里·Zolfigol
学院，理学院化学系，布阿里新浪，P.O.Box 4135，哈马丹65174，伊朗
收稿日期2001年4月9号修订日期2001年8月23日发表日期2001年9月13号
Abstract-Neat chlorosulfonic acid reacts with silica gel to give silica sulfuric acid in which sulfuric acid is immobilized on the surface of silica gel via covalent bond. Thiols can be readil
y converted to their corresponding thionitrites with a combination of silica sulfuric acid, wet SiO2and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrites and subsequent coupling of the resultant thiyl radicals. 2001 Elsevier Science Ltd. All rights reserved.
摘要规整反应，用硅胶，得到二氧化硅硫酸，其中硫酸是通过共价键固定在硅凝胶的表面上。硫醇类，可以很容易地转换为用硫酸，在室温下在二氯甲烷中的溶胀的二氧化硅和亚硝酸钠的组合其相应的硫醇类亚硝酸盐。二硫化物的不稳定硫醇类亚硝酸盐和随后耦合，所得到的硫中心自由基的硫氮键的均裂。2001 Elsevier科学有限公司保留所有权利。
Any reduction in the amount of sulfuric acid needed and/or any simplification in handling procedures is required for risk reduction, economic advantage and environment protection. In addition, there is current research and general interest in heterogeneous systems because of the importance such systems have in industry and in developing technologies. In continuation of our studies on the application of inorganic acidic salts we found that silica gel reacts with chlorosulfonic acid to give silica sulfuric acid (I). It is interesting to note that t
react to中文
he reaction is easy and clean without any work-up procedure because HCl gas is evolved from the reaction vessel immediately (Scheme 1).
任何减少硫磺酸用量或处理程序的简化，都要符合减少风险，确立经济优势和环保要求。此外，目前的研究和普遍关心的是异构系统，因为这样的系统对工业和技术发展很重要。在无机酸性盐的应用上继续我们的研究，我们发现，硅胶硫酸（I）与反应。有趣的是，该反应是容易和清洁的，因为HCl气体立即从反应容器（图1）放出，没有任何工作程序。
We hoped that the silica sulfuric acid (I) would be a superior proton source to all of the reported acidic solid supports or acidic resins such as polystyrene sulfonic acid and Nafion-H3 for running reactions under heterogeneous conditions. Therefore, we were interested in using this inorganic acidic resin (I) for the in situ generation of HNO2 when used in conjunction with NaNO2, wet SiO2 and an organic solvent. On the other hand, thionitrites have not been as widely studied as their oxygen counterparts alkyl nitrites, generally because of their reduced stability. However, in recent years there has been much interest generated in the chemistry and biochemistry of nitrosothiols, since (a) they are being exami
ned as possible drugs to effect vasodilatation and to reduce platelet aggregation, (b) they are now believed to play an important part in some of the physiological processes involving nitric oxide and (c) they are being investigated as a source of thiyl radicals or as nitrosating agents.
我们希望用硫酸（Ⅰ），硫酸将是一个优越的质子源，所有报道的酸性固体支撑物或异构的条件下运行反应的酸性树脂，如聚苯乙烯磺酸和Nafion-H3。因此，我们感兴趣的是使用这种无机酸性树脂（I）与亚硝酸钠，湿二氧化硅和有机溶剂配合使用的原位生成亚硝酸盐。另一方面，但硫醇亚硝酸盐一直是亚硝酸烷基化广泛研究的，一般是因为其稳定性降低。然而，近年来一直在亚硝基硫醇的化学和生物化学产生很大的兴趣，因为（一）它们可能药物影响血管舒张，降低血小板聚集，（B），它们现在认为在一些涉及一氧化氮生理过程发挥了重要作用及（c）它们被调查是硫中心自由基的来源或亚硝基化剂的生理过程的一部分。
The most general nitrosating reagent is nitrous acid, generated from sodium nitrite and mineral acid in water or in mixed alcohol-water solvents. Other nitrosating agents have been used successfully to synthesize thionitrites, notably alkyl nitrites, nitrosyl salts, trioxide, dinitrogen tetroxide, oxalic acid dehydrate or inorganic acidic salts and sodium nitrite. Very recently, we among many others, have demonstrated that heterogeneous reagent systems have many advantages such as simple experimental procedures, mild reaction conditions and minimization of chemical wastes as compared to the liquid phase counter-parts. Therefore, we decided to apply silica sulfuric acid(I)/NaNO2 as a new heterogeneous system for the nitrosation of thiols. We wish to report a simple, cheap and convenient method for the effective nitrosation of thiols and production of disulfides under mild and heterogeneous conditions (Scheme 2).
最一般的亚硝基化试剂是从亚硝酸钠和无机酸在水中或在醇水混合溶剂中，生成的亚硝酸。已经成功地使用的其他的亚硝基化剂合成硫代亚硝酸盐，特别是亚硝酸烷基酯，亚硝酰盐，三氧化硫，四氧化二氮，草酸脱水的或无机的酸式盐和亚硝酸钠。最近，在许多其他之中，已经证明异构试剂系统到液相反部分相比有很多优点，例如简单的实验程序，反应条件温和，
尽量减少化学废物。因此，我们决定申请硅石硫酸（I）/亚硝酸钠，亚硝化硫醇作为一个新的非均相体系。我们要报告的一个简单，经济方便的方法有效硫醇和亚硝化生产轻度和异构条件下的二硫化物（方案2）。
Different kinds of thiols were subjected to the nitrosation亚硝化reaction in the presence of NaNO2, wet SiO2(50% w/w) and silica sulfuric acid (I) in dichloromethane. The nitrosation reactions were performed under mild and completely heterogeneous conditions. A bright-red heterogeneous solution was obtained immediately due to the formation of thionitrite硫代亚硝酸盐. Disulfides result from the homolytic cleavage of the sulfur-nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals. Therefore, this method could be used for conversion of thiols to their corresponding disul des quantitatively with increasing temperature (Scheme 2 and Table 1).

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