3,6-二溴咔唑的合成工艺改进

3，6-二溴咔唑是重要的医药中间体，本文采用N-溴代丁二酰亚胺法、液溴法和硅胶法三种方法合成了3,6-二溴咔唑，实验结果表明，硅胶法为较佳路线，并通过正交实验得出最优工艺条件为：室温下反应时间为12h，原料咔唑、N-溴代丁二酰亚胺、溶剂二氯甲烷、催化剂硅胶的用量物质的量比为1：2：131：47时，产品平均收率可提高到89．25％。同时，通过单因素实验对原料配比、反应时间、溶剂用量和催化剂用量四种因素对反应的影响进行了研究。     

对溴甲基苯甲酸合成工艺研究

以对甲基苯甲酸和N-溴代丁二酰亚胺(NBS)为原料,采用过氧化苯甲酰(BPO)引发自由基反应合成对溴甲基苯甲酸。采用单因素实验,考察溶剂种类及用量、原料配比、BPO的用量及反应时间对反应的影响。结果表明,最优的合成条件是:以四氯化碳为溶剂,其用量为25.0m L,反应原料的摩尔比为n(NBS)∶n(对甲基苯甲酸)=1.05∶1.0,引发剂的用量为NBS摩尔量的0.04倍,反应时间为2.0 h。用此法合成对溴甲基苯甲酸操作简便,工艺最优,其合成收率为78.2%。     

Salen Mn(Ⅲ)/NBS催化次氯酸钠氧化4,4'-二羟基二环己烷合成4,4'-二环己酮

以Salen-Mn(Ⅲ)为催化剂、NBS为溴源构建了一种催化体系,以次氯酸钠为氧化剂成功地将4,4'-二羟基二环己烷氧化为4,4'-二环己酮。分别考察了催化剂Salen Mn(Ⅲ)、NBS以及次氯酸钠用量对反应的影响,发现当4,4'-二羟基二环己烷为0.5 mmol、Salen-Mn(Ⅲ)为0.04 mmol、NBS为0.26 mmol、次氯酸钠为18 mmol时,在25℃反应0.5 h,4,4'-二羟基二环己烷的转化率和4,4'-二环己酮的选择性分别高达96.1%和93.0%。     

溴代芴的合成研究

以碳酸丙烯酯为溶剂、以N-溴代丁二酰亚胺（NBS）为溴化试剂,进行芴的溴代反应研究,合成了2-溴芴和2,7-二溴芴。通过对反应温度、NBS的用量以及加入方式等的考察,确定合成2-溴芴的最佳反应条件。最佳反应条件为：反应温度23℃、NBS和芴的物质的量比为1．1：1、NBS分批加入。先将芴和碳酸丙烯酯预热至60℃,使得芴全部溶解,然后降至反应温度,分批加入NBS。2-溴芴和2,7-二溴芴分别以无水乙醇和冰醋酸重结晶,目标产物的液相色谱纯度均可达到99％以上。     

屈螺酮关键中间体的合成研究

以NBS为溴源,3-特戊酰氧基-5β,6β-环氧-7β-羟基-15β,16β-二亚甲基-孕甾-17-酮为原料,在三苯基膦催化剂的作用下合成了屈螺酮的关键中间体3-特戊酰氧基-5β,6β-环氧-7α-溴-15β,16β-二亚甲基-孕甾-17-酮,考察了NBS的用量、催化剂的用量、反应温度、反应时间对3-特戊酰氧基-5β,6β-环氧-7α-溴-15β,16β-二亚甲基-孕甾-17-酮收率的影响。实验结果表明,最佳投料条件下目标物的质量收率为89.5%。该方法条件温和,操作简单,易于实现工业化生产。     

4-甲酰基苯并呋咱的合成

以4-甲基苯并呋咱为起始原料,经N-溴代丁二酰亚胺(NBS)溴化、Sommelet反应制得4-甲酰基苯并呋咱。重点考察了溴化剂和引发剂对溴化反应以及原料配比、反应温度、反应时间等对Sommelet反应过程的影响。优化的工艺条件为:NBS为溴化剂、过氧化苯甲酰(BPO)为与光照引发剂,温度为62℃,时间为5 h,4-溴甲基苯并呋咱收率为86.8%;n(4-溴甲基苯并呋咱)∶n(乌洛托品)=1∶1.2,醋酸为催化剂及反应溶剂,成盐反应60℃反应2 h,酸解80℃反应4 h,产品收率达78.4%。     

2-溴-1-(3,4,5,-三甲氧基苯基)-乙酮的合成

以3,4,5-三甲氧基苯乙酮为原料,用N-溴代丁二酰亚胺(NBS)为溴化物合成2-溴-1-(3,4,5,-三甲氧基苯基)-乙酮。考察不同反应溶剂、不同反应温度和不同NBS用量以及是否添加催化剂等不同反应条件对产率的影响。溶剂为乙醇时,反应温度为45℃,n(3,4,5-三甲氧基苯乙酮)∶n(NBS)=1∶2时,产率为45.7%,因此筛选该条件为最优反应条件。化合物结构经核磁共振氢谱表证。     

溴咔唑衍生物的制备及其性能研究进展

基于溴咔唑优良的光学及药理学等特征,选取应用较广泛的溴咔唑研究其合成、性能及应用,重点介绍溴咔唑(1-溴咔唑、2-溴咔唑、3-溴咔唑、4-溴咔唑、3,6-二溴咔唑、1,3,6,8-四溴咔唑)的不同合成方法,综述溴咔唑衍生物在光学及药理学领域的应用,提出当前合成方法存在的不足,指出以溴咔唑为核心骨架拼接不同的杂环组块于同一分子在药理活性和荧光探针方面的未来研究方向。     

奥扎格雷合成工艺

研究了以4-甲基苯甲醛为原料,经克莱森缩合、N-溴代丁二酰亚胺（NBS）溴化、咪唑缩合以及碱条件下水解反应制得抗血栓药奥扎格雷的工艺。考察了反应物配比、温度控制、NBS用量、缩合反应碱的选择、水解碱用量控制等因素的影响,4步反应总收率为41.6%。     

2-(溴甲基)烟腈的合成研究

以2-甲基烟腈为原料,NBS为溴代试剂,BPO为引发剂,在四氯化碳溶液中发生自由基溴代反应得到2-(溴甲基)烟腈,产物结构通过~1H NMR和ESI-MS表征。并考察确定了该溴代反应的适宜条件为:NBS用量为n_(NBS)∶n_(2-甲基烟腈)=1.2∶1,反应溶剂为四氯化碳,反应温度60℃,反应时间7h,在该条件下,产物收率达到61.4%。     

硅胶固载γ-氯丙基三甲氧基硅烷制备水不溶性杀菌剂中间体

采用硅胶作为水不溶性杀菌剂的载体 ;以γ 氯丙基三甲氧基硅烷作为联接硅胶和杀菌活性官能团的偶联剂 ;在硅胶上键合γ 氯丙基三甲氧基硅烷的最佳反应条件为 :使用二甲苯作反应溶剂 ,80℃反应 6h以上 ,原料硅胶最好要经丙酮处理 ,γ 氯丙基三甲氧基硅烷与硅胶的质量比为 1∶1即可。使用所研制的中间体制备的水不溶性杀菌剂用量 2mg mL时杀菌率达到 98%。     

A method for bleaching rice bran oil with silica gel

The color of bleached rice bran oil can be improved by silica gel treatment of the oil miscella before or after dewaxing. A silica gel/oil/solvent ratio of 1:5:5 (wt/wt/vol) is suitable. Silica gel treatment can be carried out either by column percolation or by merely shaking the miscella with the gel followed by decantation. However, column percolation is more efficient, with 30–72% color reductionvs. 19–36% reduction for shaking and decanting.     

3-(2-噻吩)丙烯酸的合成工艺研究

以噻吩-2-甲醛为原料,与磷酰基乙酸三乙酯在氢化钠存在下反应制备3-(2-噻吩)丙烯酸乙酯,后通过水解制备3-(2-噻吩)丙烯酸,总收率78.5%,纯度98.6%,可制备121 g每批。考察了原料滴加速度、物料摩尔比、溶剂用量、柱层析硅胶用量对化合物2合成的影响,确定了最佳条件为:滴加速度8 m L/min、噻吩-2-甲醛与膦酰基乙酸三乙酯摩尔比为1:1.2,溶剂1.6 L,柱层析用硅胶与粗产物重量比为1:15,该步反应收率92.3%,水解后产物经重结晶获得纯品,收率85%。产物结构通过质谱、核磁鉴定正确。     

A method of ultraviolet spectrophotometry of lipid monolayers on silica gel

A method has been developed for visible and UV spectrophotometry of lipid monolayers after preadsorption on silica gel from solution in hydrocarbon solvents. Lipid-coated silica gel is made optically transparent in the desired spectral region by slurrying with an inert solvent mixture. Reproducible gels with nearly the same refractive index as the solvent are achieved by careful choice of mixed solvents and carefully timed settling periods. The gel is pipetted into a silica cuvette of 1 cm light path, and a 9 mm silica spacer bar is inserted between Teflon guide strips. Appropriate choice of solvent mixtures (mainly spectral grade cyclohexane and cyclooctane) permits quantitation of spectra down to 2250 Angstrom units, using a silica gel reference cell. Lipid elution from the monolayer into the solvent is usually less than 1% at the dry-mixing dilutions used. Spectra of known unsaturated carbonyl compounds adsorbed on silica show red shifts as great as 240 Angstrom units, while blue shifts as great as 100 Angstrom units are observed for tocopherol derivatives with an intact aromatic ring. Very small shifts are observed for polyenes. The extent and direction of the shifts are indicative of adsorption and its orientation and are useful in the preliminary determination of the class of an unknown compound. The silica slurry spectra of the important tocopherol oxidation products, the quinone, dimer and trimer, have been examined. Peak wavelength shifts are consistent with structures elsewhere proposed for these compounds.     

硅胶的制备及应用现状

硅胶不溶于水和任何溶剂,无毒无味,化学性质稳定,除强碱、氢氟酸外不与任何物质发生反应。根据其孔径的大小分为：大孔硅胶、粗孔硅胶、B型硅胶、细孔硅胶。由于孔隙结构的不同,因此它们的吸附性能各有特点。硅胶是一种高活性的吸附材料,通常以硅酸钠和硫酸为原料制备,文中介绍了各种硅胶的生产工艺,论述了硅胶的应用现状。     

Design and operation of a modified silica gel column chromatography

Liquid–solid chromatography (LSC) is the oldest of the various liquid chromatography methods. Despite the fact that high-performance liquid chromatography (HPLC) operation leads to better separation and analysis, classical column chromatography and thin-layer chromatography (TLC) are still widely practiced because of their convenience. In this study, a modified silica gel column chromatography was designed with the objective of reducing the amount of solvent required to achieve the same degree of separation as the classical silica gel column chromatography. The separation of squalene and fatty acid steryl esters (FASEs) from non-polar lipid fraction (NPLF) of soybean oil deodorizer distillate (SODD) was employed as a model system to test the effectiveness of this new design. Modified silica gel column chromatography process is feasible from economic point of view compare to classical silica gel column chromatography because it significantly reduces the amount of solvent and time required to achieve the same degree of separation. By employing modified silica gel column chromatography to obtain the squalene-rich fraction, the mobile phase volume and elution time required as fractions of those needed in classical silica gel column chromatography are 1/73 and 1/18, respectively. To obtain the FASEs-rich fraction, the corresponding mobile phase volume and elution time are 1/221 and 1/23, respectively of those needed in classical silica gel column chromatography.     

Purification of cholesterol from lanolin by column chromatography

采用柱层析法分离羊毛脂中的胆固醇,以胆固醇与杂质羊毛甾醇的分离度为判定依据来筛选吸附剂及优化层析工艺,同时对吸附剂进行了再生考察。实验表明,当以200～300目粗孔硅胶为吸附剂、丙酮/正己烷混合溶剂（体积比4∶96）为流动相、35 ℃下胆固醇上载量为2.4%（质量分数）时,胆固醇的分离效果较好,所得胆固醇含量可达84.36%,收率为85.67%。另外选用丙酮/正己烷混合溶剂（体积比50∶50）对吸附剂进行再生处理,硅胶经7次使用再生循环,分离效果未降低。     

减压液相色谱法制备季戊四醇三乙酸酯

以季戊四醇和乙酸酐(摩尔比为1∶3)为原料,回流反应,生成季戊四醇一、二、三、四乙酸酯的混合物,用减压液相色谱(VLC)法制备出了纯度为98.5%的季戊四醇三乙酸酯。VLC的吸附剂采用薄层层析用硅胶,硅胶颗粒细,吸附能力强,载样量大。凭借真空的动力加速溶剂的流动。该法操作简便、分离效率高、溶剂用量少、快速省时。     

Processability studies of silica‐thermoset polymer matrix nanocomposites

The aim of this study is to investigate the processability of silica‐thermoset polymer matrix nanocomposites in terms of dispersion of silica nanoparticles and their effect on curing. Two thermosetting resins were considered, an epoxy and a polyester resin, with 5% silica, although 1% silica was also used in preliminary studies in the polyester system. Various combinations of mechanical mixing and sonication were investigated for the dispersion of silica nanoparticles under different processing conditions and times in solvent‐free and solvent‐containing systems. It was found that the best dispersion route involved a solvent‐aided dispersion technique. Consequently, different procedures for the solvent removal were investigated. Optical microscopy and SEM were used to characterize the resulting nanocomposites. DSC and rheological DMTA tests demonstrated that the silica nanoparticles shorten the gel time and promote curing in these thermosetting systems. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers     

TLC Separation of Glucopyranosyl Sinapate and Other Phenolic Compounds from Rapeseed

Glucopyranosyl sinapate was obtained from rapeseeds using column chromatography on Sephadex LH-20 and RP-18 semipreparative HPLC. TLC analysis of this compound, sinapic acid and phenolic compounds fractions from column chromatography were conducted on plates coated with silica gel (standard and HPTLC), with cellulose and on RP-TLC plates. Eleven various solvent systems were applied to develop chromatograms. HPTL plates were found more efficient than those coated with standard silica gel. Compared to the latter cellulose ensured worse results of TLC analysis. The best developing system for plates coated with silica gel was benzene-methanol-acetic acid (90:16:8). Separation of the compounds analysed using RP-TLC depended on octadodecylsilanization degree of silica gel on TLC plate.