4-正丁基-2-硝基苯胺的制备

以对正丁基苯胺为原料,合成了4-正丁基-2-硝基苯胺。经过酰化,硝化,水解三步反应,总收率可达72%。以醋酐为溶剂用浓硝酸硝化,最后用乙醇作溶剂水解得到目标产物。实验得出物料的最佳配比为:n(对正丁基苯胺)∶n(乙酸酐)=1∶3,n(对正丁基乙酰苯胺)∶n(醋酐)∶n(浓硝酸)=1∶3∶5,n(4-正丁基-2-硝基乙酰苯胺)∶n(氢氧化钾)=1∶1.3。     

3-烃硫基-4-甲基-N-(二乙氨基乙基)苯胺类化合物的制备

3-烃硫基-4-甲基乙酰苯胺,1-氯-2-二乙氨基乙烷与粉末氢氧化钾在丙酮中作用,不经分离3-烃硫基-4-甲基-N-(二乙氨基乙基)-N-乙酰苯胺类化合物,而直接用盐酸水解得3-烃硫基-4-甲基-N-(二乙氨基乙基)苯胺类化合物六种,但3-丙烯硫基-4-甲基-N-(二乙氨基乙基)苯胺应用此法制备未获成功,继改用3-丙烯硫基-4-甲基苯胺与1-氯-2-二乙氨基乙烷作用制得。     

2-氯-4,6-二苯氨基-1,3,5-三嗪改性纤维素的制备、结晶结构与水解性能

目前, 纤维素水解产生可发酵糖的效率很低, 是纤维素-乙醇转化的瓶颈问题. 拟以化学改性的方法改变纤维素结晶结构从而提高其水解效率. 首先以三聚氰氯(TCT)、苯胺为原料, 合成2-氯-4,6-二苯氨基-1,3,5-三嗪(DACT), 通过红外光谱、核磁共振谱图表征其结构. 将DACT用于微晶纤维素羟基的修饰, 并将修饰后的纤维素于50 ℃、固液比为1∶20 (W/V)比为条件下用70 wt%硫酸水解60 min, 研究DACT用量对纤维素结晶结构和水解性能的影响. 水解实验结果表明DACT的相对物质的量的百分含量(以葡萄糖环计)为30%左右时, 改性纤维素经酸催化水解后还原糖得率最高, 广角X射线衍射证实该水解结果可归因于化学改性令纤维素的结晶结构发生变化, 利于纤维素水解产生可发酵糖.     

多色染料的合成——综合设计型化学实验

将2-氨基苯酚-4-(2′-羧基)磺酰苯胺重氮化,分别与乙酰乙酰苯胺、2-萘酚、1-苯基-3-甲基-5-吡唑啉酮等偶合,得到不同的偶氮物,然后再分别与硫酸铬或氯化钴进行络合反应,得到多种颜色的染料,并进行了毛织品的染色实验。该产物的色彩艳丽,实验周期合理,达到了预期的综合设计实验的目标。     

间氨基茴香醚的合成

以间氨基苯酚为原料,经乙酰化、甲基化和碱水解合成了间氨基茴香醚,3步反应的收率分别为90.7%,82.8%和88.2%。最佳的甲基化反应条件为:间羟基乙酰苯胺56 mmol,n(间羟基乙酰苯胺)∶n(M e2SO4)∶n(NaOH)=1.0∶1.5∶1.2,回流反应8 h,四氯化碳为溶剂。     

手持技术支持下的乙酸乙酯水解实验探究*

乙酸乙酯的水解实验是现行高中有机化学教学内容中的重要实验,教材中提出通过观察酯层消失的时间差异来判断水解速率的差别,在实际操作过程中实验效果并不理想。借助手持技术分别探究了乙酸乙酯在中性、酸性、碱性、不同温度条件下的水解速率情况,并借助相关知识理论分析了乙酸乙酯在酸性和碱性条件下水解速率的差异,旨在帮助教师和学生深度理解乙酸乙酯发生水解的条件及规律。     

有机化学实验课上的细节教学——以合成乙酰苯胺为例

以合成乙酰苯胺为例说明细节教学对于有机化学实验取得预期效果的重要性。首先将学生分组,采用不同的方法进行教学,然后将学生的实验结果进行对比分析;结果表明细节教学与学生实验的正确操作直接相关。归纳、解析了学生在乙酰苯胺合成实验中的常见问题,并对教师教学时应强调和指导的要点提出了建议。     

苯甲酰基乙酸乙酯的合成

苯甲酰基乙酸乙酯是合成苯甲酰基乙酰苯胺等的重要原料,后者是彩色照相成色剂,又是其它彩色成色剂的中间体,也是稀土及金属的重要试剂。苯甲酰基乙酸乙酯的合成方法,都是由乙酰基乙酸乙酯在金属锂、钠、镁和无水条件下与苯甲酰氯反应,然后再水解制得。但这种方法不适宜制备量大的。     

氯代苯胺液相催化加氢合成环己酮

提出了一种催化降解氯代苯胺高选择性合成环己酮的技术.在La修饰Pd/Al2O3催化剂作用下,通过催化加氢的方法实现了由多氯代苯胺(2,4,6-三氯苯胺和2,4,-二氯苯胺)高选择性地合成环己酮(不含环己醇).在优化的反应条件下,2,4,6-三氯苯胺加氢生成环己酮的转化率和选择性分别为100%和98.6%(没有检测到环己醇);2,4,-二氯苯胺加氢生成环己酮的转化率和选择性均为100%.氯代苯胺在Pd/La-Al2O3催化剂表面首先发生加氢脱氯/N-甲基化等反应生成苯胺、N-甲基苯胺和N,N-二甲基苯胺等中间产物,随后这些中间产物发生苯环加氢、氨基水解/醇解等反应得到环己酮;氯代苯胺上Cl元素的存在和体系中水的含量是影响环己酮选择性的重要因素.     

NAMI-A乙基取代衍生物水解机理的DFT研究

采用密度泛函理论(DFT)方法,并结合导体极化连续模型(CPCM)研究了[(N-EtIm)H][trans-RuⅢCl4(DMSO)(N-EtIm)](N-EtIm=N-乙基咪唑)分别在中性及酸性条件下的水解反应过程.同时,为提高溶剂化能的精确度,在中性条件下水解反应的计算中采用3个水分子的溶剂化模型.计算得到水解反应过程中相应的结构特征和详细的热力学能量及速率常数.首先,在中性条件下,对于第一步水解,液相中配合物的活化能垒为109.9kJ/mol,速率常数为3.3×10-7 s-1,与实验中测得的第一步水解反应的速率常数(4.4×10-7 s-1)一致.对于第二步水解,反应的活化能垒为117.9kJ/mol,这符合实验中观察到的第二步水解比第一步水解反应慢的现象.其次,计算结果表明,酸性条件下,DMSO基团易于水解,Cl-水解困难,这也与实验结果相吻合.     

Hydrolysis characteristics of tissue fractions resulting from mechanical separation of corn stover

Corn stover has potential as a resource for both fiber and chemical needs if separation strategies can be developed to deal with its heterogeneity. Relative hydrolysis characteristics were assessed for pith (sclerenchyma and parenchyma) and fiber (collenchyma) tissue fractions derived from mechanical separation of corn stover to determine whether classification by tissue type resulted in fractions with different hydrolysis response. The physical characteristics of the tissue fractions were analyzed. The hydrolysis behavior of the fractions was evaluated under both acidic and basic conditions. The results from the hydrolysis experiments are compared with previously reported compositional analysis for the tissue fractions.     

An alternative synthetic process of <Emphasis Type="Italic">p</Emphasis>-acetaminobenzenesulfonyl chloride through combined chlorosulfonation by HClSO<Subscript>3</Subscript> and PCl<Subscript>5</Subscript>

p-Aminobenzene sulfonamide (sulfanilamide, SN) is the simplest and most-used sulfonamide medicine. The key step of SN production via the commonly used chlorosulfonic acid routine is the synthesis of p-acetaminobenzenesulfonyl chloride (P-ASC). A large amount of HSO₃Cl has to be used in the traditional process, which results in serious environmental problems. In this study, an alternative chlorosulfonic acid process to synthesize P-ASC was investigated by partially substituting HSO₃Cl by PCl₅ as the chlorination agent. Compared with the traditional process, the molar ratio of HSO₃Cl to acetanilide (the main raw material) can be decreased from 4.96 to 2.1 using CCl₄ as the diluent; also, addition of a small amount of NH₄Cl was found to significantly increase the P-ASC yield. Operating conditions of the reaction were studied first by single-factor experiments and later by orthogonal experiments to obtain optimum operating conditions under which the P-ASC yield can reach as high as 86.3 %.     

乙酰苯胺在超声波作用下的N—烷基化

超声波作为一种新型能量形式用于许多有机反应。我们对乙酰苯胺的相转移催化N-烷基化反应进行了研究。发现超声波作用能使反应在室温下顺利进行,反应产率令人满意。 所用试剂除卤代正丁烷为化学纯外均为分析纯。超声波装置为上海超声波仪器厂CQ-250型超声波清洗仪。红外光谱由岛津IR-408型仪器测定。 在圆底烧瓶中加入乙酰苯胺2.7g(0.02mol),适量相转移催化剂(PTC),50mL苯,4g氢氧     

First aromatic ring acetamidation by anodic oxidation

Anodic oxidation of 1-(trifluoromethyl)benzene in dry acetonitrile/Bu₄NBF₄ under constant potential conditions led to 2-(trifluoromethyl) acetanilide in 86% yield. Other experimental conditions, as the use of constant current or the change in the supporting electrolyte were considered.     

Catalytic Performance and Dispersion Behavior of Supported Nano‐Amorphous Alloy NiB/MCM‐41 Catalysts Prepared by Chemical Reductive Deposition

Supported nano‐amorphous alloy NiB/MCM‐41 catalysts were prepared by chemical reductive deposition. The as‐prepared catalysts were characterized by XRD, SEM, TEM, EDAX, ICP, and N₂ adsorption‐desorption. The amorphous alloy structure of NiB active sites, mesoporous structure of catalysts, and higher BET area have been proved by the experiments. The catalysts have given excellent catalytic activity and selectivity in the production of 3‐(N‐benzyl)‐amino‐4‐methoxy‐ acetanilide from 3‐amino‐4‐methoxy‐acetanilide and benzaldehyde.     

Electrochemical Fluorination of Benzamide and Acetanilide in Anhydrous HF and in Acetonitrile

Electrochemical fluorination of benzamide in anhydrous hydrogen fluoride does not involve the amide group but occurs exclusively at the aromatic ring, yielding isomeric fluoro- and difluorobenzamides and 3,3,6,6-tetrafluoro-1,4-cyclohexadienecarboxamide. Electrochemical fluorination of benzamide in acetonitrile as solvent gives the same products, as well as benzonitrile and its fluorinated derivatives and products of hydrolysis and fluorination of acetonitrile. Electrochemical fluorination of acetanilide in anhydrous HF leads to complete tarring of the reaction mixture, while its fluorination in acetonitrile results in selective formation of m-fluoroacetanilide.     

Acetanilide mediated reversible assembly and disassembly of Au nanoparticles

Herein we report the generation of Au nanoparticles (NPs) by sparingly soluble acetanilide in water. We also report the formation of linear chain-like superstructures of self-assembled Au NPs, in the presence of excess acetanilide. This was achieved in two different ways. In the first method, acetanilide was added, with increasing concentration, into aqueous HAuCl(4) to produce Au NPs as well as for the formation of assembly, which varied according to the concentration of acetanilide. The other route involved formation of spherical Au NPs at the lowest concentration of acetanilide, which was followed by the formation of assembly of various lengths upon further addition of variable amount of acetanilide. The assemblies were stable in aqueous solution for days with characteristic UV-vis absorption spectra consisting of two peaks. While the wavelength of the first peak remained the same, the position of the second peak changed to longer wavelength with increasing acetanilide concentration. Interestingly, the linear chain-like arrays could be broken into individual particles by first dilution of the solution concentration followed by treatment with ultrasonic waves. The individual Au NPs again formed linear chain-like arrays upon addition of excess acetanilide.     

Design of experiments, a powerful tool for method development in forensic toxicology: application to the optimization of urinary morphine 3-glucuronide acid hydrolysis

The application of the design of experiments to optimize method development in the field of forensic toxicology using the urinary morphine 3-glucuronide acid hydrolysis as an example is described. Morphine and its trideuterated analogue (used as an internal standard) were extracted from urine samples by liquid–liquid extraction (ToxiTubes® A) and derivatized by silylation. Chromatographic analysis was done by gas chromatography–mass spectrometry in the selected ion monitoring mode. Using the peak area ratio (morphine-to-internal standard) as the response, we investigated the independent variables that could influence the acid hydrolysis, including temperature (range 70–130?°C), acid volume (range 500–1,000?µL) and time (range 15–90 min). A 2³ full factorial design for the screening and a response surface methodology, including a central composite design for optimization, were applied. The factors which influenced the response to a greater extent were temperature and its interaction both with time and acid volume. By application of a multiple regression analysis to the experimental data, a second-order polynomial equation was obtained. The optimal predicted conditions for morphine 3-glucuronide acid hydrolysis were 115?°C, 38 min and 500?µL for temperature, time and acid volume, respectively. Using design of experiments, instead of the one factor at a time approach, we achieved the optimum combination of all factor values, and this allowed the best results to be obtained, simultaneously optimizing resources. In addition, time and money can be saved, since other approaches are in general more time-consuming and laborious, and do not take into account the interactions between factors.     

Controlled acid hydrolysis and kinetics of flavone C-glycosides from trollflowers

Acid hydrolysis mechanisms of orientin-2"-O-galactopyranoside(OGA),orientin and other flavone C-glycosides in the trollflowers[Trollius chinensis Bunge) were studied in this report for the first time.Hydrolysis parameters including temperature,acidity,solvent and reaction time were comprehensively investigated.OGA could be hydrolyzed to orientin,followed by an isomerization to isoorientin via a reversible Wessely-Moser rearrangement reaction under stronger acidic conditions.A first-order kinetic model fitted the hydrolysis process of OGA well.Under the optimal hydrolysis conditions of 80 ℃,1.0 mol/L H~+ and 7 h reaction time,about 77%OGA was transformed to orientin with no detectable isoorientin.These results could be helpful for better understanding of the acid hydrolysis kinetics of flavone C-glycosides,as well as the preparation of these valuable components under controlled acid hydrolysis conditions.