邻,对二硝基苯的相转移催化甲氧基化反应探讨

利用相转移催化还甲氧基反应,对精制间二硝基苯进行处理,将其中的邻,对位异构体转化为对应的硝基苯甲醚 ,经处理后的粗制间二硝基苯可用于制备高纯度的间苯二胺。     

间氨基苯甲醚合成的研究

本文研究了以间二硝基苯为原料经相转移催化醚化，水合肼还原的工艺，对各步反应的条件和影响因素进行了讨论。     

滴流床反应器中镍基催化剂催化加氢合成间苯二胺工艺的研究

以Ni／La2O3-SiO2为催化剂,采用滴流床反应器较系统地考察了反应温度、压力、气体和液体空速、溶剂等因素对问二硝基苯液相催化加氢合成间苯二胺反应的影响规律。结果表明,在较佳的温度范围内催化剂具有较好的间二硝基苯转化率及间苯二胺选择性,温度过低间苯二胺选择性较低,而温度过高会使间二硝基苯的转化率下降。反应压力及氢气空速提高、间二硝基苯液时空速降低均有刺于提高间二硝基苯的转化率和间苯二胺的选择性。乙酸乙酯对间二硝基苯有良好溶解性能,以乙酸乙酯作为溶剂可以提高催化剂的反应性能。在实验确定的适宜加氢反应工艺条件下,间二硝基苯转化率和间苯二胺选择性均可以达到99．5％以上。     

采用相转移催化法精制粗间二硝基苯

采用相转移催化法对租间二硝基苯进行醚化处理,将其中的邻、对位异构体转化为对应的硝基苯醚,考察了不同烷氧基化试剂及季铵盐、反应条件、聚乙二醇和季铵盐与聚乙二醇两者复配对间二硝基苯精制反应的影响.结果表明,以甲醇为烷氧基化试剂,四丁基溴化铵为催化剂时,醚化效果较好.在粗间二硝基苯、甲醇、NaOH(质量分数40%)和四丁基溴...     

进口己内酰胺现场快速定性鉴定方法的研究

建立了用间二硝基苯快速检测己内酰胺的方法,采用含有2%间二硝基苯的乙醇溶液与己内酰胺在氢氧化钾存在下的显色反应进行。实验结果表明,该方法简便、快速,成本低,适合己内酰胺的现场快速定性测定。     

间二氯苯两种合成工艺路线的比较

通过间二氯苯两种合成工艺路线、反应原理、工艺流程、三废处理等进行分析比较，推荐应用间二硝基苯一步氯化法。     

地衣芽孢杆菌转化间二硝基苯为间硝基苯羟胺、间硝基苯胺和间苯二胺的研究

从土壤中筛选得到1株转化间二硝基苯的芽孢杆菌,经生理生化实验及16SrDNA序列分析,确定其为地衣芽孢杆菌CGMCC2280。对含间二硝基苯的菌体转化液在不同时间取样,分离纯化得到化合物A、B和C,通过LC-MS和1 HNMR分析,同时与标准品对照,确定化合物A、B和C分别为间硝基苯羟胺、间硝基苯胺和间苯二胺。底物特异性表明,该菌对间二硝基苯和邻二硝基苯的底物转化率10h达到98%以上,但对对二硝基苯的底物转化率却不到10%。转化液中葡萄糖具有促进间二硝基苯还原的作用,在没有葡萄糖存在的情况下,转化反应速度较慢,且反应后期反应产物间苯二胺会进一步降解。在转化反应的不同时间加入丙酮终止反应并进行产物分析,发现该菌还原间二硝基苯的转化过程是先形成间硝基苯羟胺,再形成间硝基苯胺,最后形成间苯二胺。     

负载型纳米钌催化剂催化加氢合成间苯二胺工艺研究

以高分子/二氧化硅双重负载的纳米钌为催化剂,由间二硝基苯液相催化加氢制备间苯二胺,考察了反应温度、压力、催化剂用量、溶剂等对催化反应的影响,同时对催化剂的稳定性进行了研究。结果表明,该催化剂具有很高的催化活性,以甲醇为溶剂,间二硝基苯初始浓度0.5 mol/L,温度80℃,压力1.5MPa,反应1.5 h后间二硝基苯转化率和间苯二胺选择性分别达到95.6%和99%以上;同时,催化剂具有良好的稳定性,经过25次套用实验后,催化剂的反应性能未发生明显变化。     

聚乙二醇催化合成间硝基茴香醚的研究

以间二硝基苯为原料，用聚乙二醇（ＰＥＧ）作相转移催化剂，一步合成了间硝基茴香醚，并考察了各因素对反应的影响，操作简单，成本低，适合工业生产。     

三相相转移催化法精制粗间二硝基苯

以氯甲基聚苯乙烯树脂分别与三甲胺、三乙胺、三丁胺、三乙醇胺、吡啶5种叔胺反应,制备了不同的聚合物三相相转移催化剂,并用于间二硝基苯精制,考察了催化剂、氢氧化钠、甲醇的用量及催化剂种类对邻、对二硝基苯转化率的影响,得到了适宜的精制工艺条件为:m(粗间二硝基苯)∶m(甲醇)∶m(NaOH)∶m(聚苯乙烯吡啶树脂)=1∶0.8∶0.1∶0.12,反应温度76～78℃,反应时间2 h。在该条件下,邻对二硝基苯的转化率在99.5%以上,精制后的间二硝基苯经色谱分析后其色谱纯度达99.8%,间二硝基苯的收率在99%左右,聚苯乙烯吡啶树脂催化剂可重复使用7次以上。     

Hydrogenation of m‐dinitrobenzene to m‐phenylenediamine over La2O3‐promoted Ni/SiO2 catalysts

BACKGROUND: Liquid‐phase catalytic hydrogenation of m‐dinitrobenzene is an environmentally friendly routine for m‐phenylenediamine production. The key to increasing product yield is to develop catalysts with high catalytic performance. In this work, La₂O₃‐modified Ni/SiO₂ catalysts were prepared and applied to the hydrogenation of m‐dinitrobenzene to m‐phenylenediamine. The effect of La₂O₃ loading on the properties of Ni/SiO₂ was investigated. The reaction kinetic study was performed in ethanol over Ni/3%La₂O₃–SiO₂ catalyst, in order to clarify the reaction mechanism of m‐dinitrobenzene hydrogenation. RESULTS: It was found that the activity of the silica supported nickel catalysts is obviously influenced by La₂O₃ loading. Ni/3%La₂O₃–SiO₂ catalyst exhibits high activity owing to its well dispersed nickel species, with conversion of m‐dinitrobenzene and yield of m‐phenylenediamine up to 97.1% and 94%, respectively. The results also show that Ni/3%La₂O₃–SiO₂ catalyst can be reused at least six times without significant loss of activity. CONCLUSION: La₂O₃ shows strong promotion of the effect of Ni/SiO₂ catalyst for liquid‐phase hydrogenation of m‐dinitrobenzene. La₂O₃ loading can affect the properties of Ni/SiO₂ catalyst. Based on the study of m‐dinitrobenzene hydrogenation kinetics over Ni/3%La₂O₃–SiO₂ catalyst, a possible reaction mechanism is proposed. Copyright © 2009 Society of Chemical Industry     

间苯二胺的合成

介绍了用工业间二硝基苯、Fe粉在HCl溶液中还原合成间苯二胺的工艺条件。本产品纯度高，稳定性好。     

非诱变性间苯二胺衍生物的合成工艺研究

由 2 ,4-二硝基氯苯出发 ,经亲核取代、加氢还原两步合成了三种非诱变性间苯二胺衍生物 :2 ,4-二氨基苯丙醚 ,2 ,4-二氨基苯丁醚和 2 ,4-二氨基苯基 -β-羟乙基醚。在合适的反应条件下 ,合成这三种化合物的总产率分别为 91 .0 % ,90 .8%和 74.1 %。所合成的三种二胺化合物可替代间苯二胺用于染料的生产     

氟代脱硝合成芳香氟化物的初步探索

以间二硝基苯为反应底物,探讨了氟代脱硝合成间硝基氟苯中反应溶剂、反应时间等因素对收率的影响。该法是一种新型的合成芳香氟化物方法,与传统的方法相比较,具有反应容易、工艺简单等优点。     

The Synthesis and Ultraviolet Spectra of Nitrodiphenylamine Disperse Dyes I–Derivatives of 2, 4– and 2, 6–Dinitrodiphenylamine

Condensation of l–chloro–2, 4– and –2, 6–dinitrobenzene with arylamines readily affords the corresponding dinitrodiphenylamines.     

2-氨基-4-氯-5-硝基苯酚的合成

以对二氯苯为原料,经双硝化、水解羟基化、选择还原氨化的路线,合成了双酰胺基苯酚型青成色剂的主要中间体２ 氨基 ４ 氯 ５ 硝基苯酚（Ⅲ）。硝化产率７４％,纯度８０５３％;羟基化产率４５％,纯度９９８３％;选择还原产率６４％,纯度９９８９％。     

A Novel Cocrystal Explosive of HNIW with Good Comprehensive Properties

In order to improve the safety of the high explosive 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane (HNIW), we cocrystallized HNIW with the insensitive explosive DNB (1,3‐dinitrobenzene) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that it belongs to the orthorhombic system with space group Pbca. Therein, layers of DNB alternate with bilayers of HNIW. Analysis of interactions in the cocrystal indicated that the cocrystal is mainly formed by hydrogen bonds and nitro‐aromatic interactions. Moreover, the thermal behavior, sensitivity, and detonation properties of the cocrystal were evaluated. The results implied that the melting point of the cocrystal is 136.6 °C, which means an increase of 45 °C relative that of pure DNB. The predicted detonation velocity and detonation pressure of the cocrystal are 8434 m s⁻¹ and 34 GPa, respectively, which are similar to that of the reported HNIW/TNT cocrystal, but its reduced sensitivity (H₅₀=55 cm) makes it an attractive ingredient in HNIW propellant formulations.     

Preparation and Performance of a BTF/DNB Cocrystal Explosive

An energetic cocrystal containing benzotrifuroxan (BTF) and 1,3‐dinitrobenzene (DNB) in 1 : 1 molar ratio was prepared by slow evaporation of solvent. The structure of the cocrystal was determined by single crystal X‐ray diffraction (XRD). It belongs to the monoclinic crystal system with space group P2₁/c. The performance of the cocrystal was evaluated on the basis of thermolysis, impact sensitivity, and detonation properties. Differential scanning calorimetry (DSC) revealed that the cocrystal has a melting point of 130 °C, which is an increase of 38 °C compared to pure DNB; the decomposition temperature is similar to that of pure BTF. The cocrystal exhibits an impact height with 50 % ignition probability of 88 cm, suggesting a substantial reduction in impact sensitivity compared to pure BTF. Furthermore, the cocrystal is predicted to have a detonation velocity of about 7373 m s⁻¹ and a detonation pressure of about 24 GPa, respectively, indicating excellent detonation performance.     

Nitration of nitrobenzene at high‐concentrations of sulfuric acid: Mass transfer and kinetic aspects

This article reports studies on mass transfer and kinetics of nitration of nitrobenzene at high concentrations of sulfuric acid in a batch reactor at different temperatures. The effects of concentration of sulfuric acid, speed of stirring, and temperature on mass transfer coefficient were investigated. The kinetics of nitration under homogenized conditions was studied at different sulfuric acid concentrations at these temperatures. The reaction rate constants were determined. The variation of rate constant with sulfuric acid concentration was explained by the M_c function. The activation energies of the reactions were determined from the Arrhenius plots. The regimes of the reactions were determined using the values of the mass transfer coefficients and the reaction rate constants. A model was developed for simultaneous mass transfer and chemical reaction in the aqueous phase. The yields of the three isomers of dinitrobenzene were determined, and the variation of isomer distribution with sulfuric acid concentration and temperature was analyzed. This work demonstrates that more than 90% conversion of nitrobenzene is possible at high‐sulfuric acid concentrations resulting in high yield of the product even at moderate temperatures and at low speeds of stirring. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Thiol–Disulphide Interchange Reactions in the Setting of Single Wool Fibres

Wool fibres pretreated with fluoro–2, 4–dinitrobenzene, N–ethylmaleimide, peracetic acid, or nitrous acid set less readily than untreated fibres when stretched for 1 h at 100C in water or acetate buffer at pH 5. Incorporation of sodium bisulphite in the setting solution at concentrations greater than 0005 M eliminated these differences, except for fibres that had been treated with nitrous acid. The set retained by both untreated and modified fibres was increased by the addition of bisulphite to the setting solution. The presence of bisulphite in the solution used for releasing (1 h at 100C) the fibres set in the absence of bisulphite decreased the set retained, but had no effect if the fibres were set in the presence of bisulphite. Treatment of the unmodified wool fibres with solutions of bromine, peracetic acid, or methyl mercuric iodide before and during release at 100C greatly increased the set retained in an acetate buffer. Similar aftertreatments of the modified fibres caused a relatively small increase in set. Setting in buffer solutions at pH 9, when followed by release in the same solution, was only slightly decreased in extent by pretreatment of the fibres with N–ethylmaleimide or peracetic acid, whereas setting was prevented by pretreatment with fluoro–2, 4–dinitrobenzene or nitrous acid. The presence of sulphite in the solutions used for setting or releasing the fibres did not affect the result. It is suggested that rearrangement of disulphide bonds by a thiol–disulphide interchange reaction is chiefly responsible for setting of wool fibres at pH 5 in the absence of a reducing agent, but that a second type of interaction, possibly the formation of β–keratin, assumes great importance when the fibres are set in bisulphite solution. Setting at pH 9 probably takes place by the formation of new covalent linkages. Lysine side–chain groups may participate in the formation of these linkages.