固体碱碱性位对丙酮和碳酸二甲酯反应的影响

考察了固体碱不同的碱性位对丙酮和碳酸二甲酯反应的影响,并对反应在不同碱性位上的反应机理进行了推测．实验结果表明,由表面羟基引起的弱碱位有利于丙酮自身缩合反应的进行,主产物为二丙酮醇、4-甲基-3-戊烯-2-酮和4-甲基4-戊烯-2-酮;Lewis酸碱离子对有利于碳酸二甲酯的甲基化反应的发生,主产物为2-甲氧基丙烯;而由固体碱表面配位不饱和的O^2-所造成的强碱位有利于碳酸二甲酯的甲氧基羰基化产物的生成,主产物为乙酰乙酸甲酯;同时发现各种产物的收率与对应的各碱性位的碱量之间均具有较好的线性关系．     

1,10-邻菲咯啉-5,6-二酮制备反应中副产物的形成与控制

由1,10-邻菲咯啉合成1,10-邻菲咯啉-5,6-二酮反应的副产物的形成与控制研究表明,1,10-邻菲咯啉在5,6位二酮化反应中的副反应产物及主产物分离时产生的副产物均为4,5-二氮杂芴-9-酮,二酮化反应条件(包括作为氧化剂的强混合酸H2SO4/HNO3的加入量、时间和温度)和主产物分离时体系的酸度对副产物的形成有重要影响,优化了二酮化反应条件和产物分离时的体系pH控制范围。在此优化条件下,可有效控制副产物的形成,使主产物1,10-邻菲咯啉-5,6-二酮的收率达到92%以上。     

基于配合共保护策略合成γ-L-谷氨酰二肽的新方法

提出了一种采用谷氨酸席夫碱Ni(II)配合物共保护L-谷氨酸的α-氨基和α-羧基合成γ-L-谷氨酰二肽的新方法. 首先由手性助剂——2-[N-(N-苄基-脯氨酰)氨基]二苯甲酮(1)、六水合氯化镍和L-谷氨酸反应, 得到谷氨酸席夫碱Ni(II)配合物2, 产率为98.2%; 进而采用二异丙基碳二亚胺(DIC)/1-羟基-苯并三唑(HOBt)复合缩合剂法分别与L-氨基酸3a～3h反应, 得到相应的γ-L-谷氨酰二肽席夫碱Ni(II)配合物4a～4h, 产率为93.1%～99.0%; 最后稀酸水解配合物, 得到γ-L-谷氨酰二肽5a～5h, 产率为73.0%～86.4%, 高收率(92.2%～97.4%)回收手性助剂. 中间产物和终产物的结构经由旋光, 1H NMR, 13C NMR和HRMS表征.     

从羊毛醇中提取胆甾醇的工艺研究

以羊毛醇为原料,提出了一条经过配合、水解及重结晶生产胆甾醇产品的工艺路线,研究了各工艺条件的影响。所得优化工艺条件为:配合过程的氯化钙摩尔量为胆甾醇摩尔量的7倍,温度78℃,时间3h;配合物纯化过程的溶剂为石油醚-乙醇混合溶剂,体积比为10∶1到13∶1,用量4mL/(g羊毛醇),冷却最终温度为20℃到10℃;配合物的水解选择用直接水解工艺,水解温度15℃,水与配合物的质量比为100∶1,水解时间1h;重结晶溶剂为乙醇。在上述条件下,所得胆甾醇产品的收率可达77%以上,纯度可达90%以上。     

α-羟基辛酸及其交酯的合成工艺改进

以正庚醛为原料,经过亲核取代、置换反应、酸水解及碱化脱氨等4步反应合成了制备3,6二已基-1,4-二氧杂-2,5-二酮(辛交酯)的中间体--α-羟基辛酸(1);1经对甲苯磺酸催化脱水得辛交酯.改进并优化了合成工艺,1收率由58.0%提高至77.6%,辛交酯收率由65.0%提高至71.0%.     

N,N′,N",N"'-四对甲苯磺酰-1,4,7,10-四氮杂环十二烷的微波常压快速水解

N,N′,N",N"'-四对甲苯磺酰-1,4,7,10-四氮杂环十二烷是Atkins法合成1,4,7,10-四氮杂环十二烷的关键中间体,但其水解脱磺酰基比较困难,常规水解一般需要采用96%～98%硫酸在140℃左右加热2～3 d.报道了一种微波促进快速水解法,即在稍加改装或未改装的家用微波炉中,采用95%～98%硫酸,控制火力2～5档,全对甲苯磺酰化全氮冠醚仅需50～120s即可完成水解,比常规加热水解所需时间缩短约3000～8000倍,浓硫酸用量也比常规加热水解少,收率较常规水解高.     

N,N′,N″,N''''''''''''-四对甲苯磺酰1,4,7,10-四氮杂环十二烷的微波常压快速水解

N ,N′ ,N″ ,N 四对甲苯磺酰 1,4,7,10 四氮杂环十二烷是Atkins法合成 1,4,7,10 四氮杂环十二烷的关键中间体 ,但其水解脱磺酰基比较困难 ,常规水解一般需要采用 96%～ 98%硫酸在 14 0℃左右加热 2～ 3d .报道了一种微波促进快速水解法 ,即在稍加改装或未改装的家用微波炉中 ,采用 95 %～ 98%硫酸 ,控制火力 2～ 5档 ,全对甲苯磺酰化全氮冠醚仅需5 0～ 12 0s即可完成水解 ,比常规加热水解所需时间缩短约 3 0 0 0～ 80 0 0倍 ,浓硫酸用量也比常规加热水解少 ,收率较常规水解高 .     

1H-吡唑-4-甲酸的合成改进

以氰乙酸乙酯和原甲酸三乙酯为原料,通过Claisen酯缩合、合环、脱氨和水解得到1H-吡唑-4-甲酸.用质谱(MS)、核磁共振氢谱(1HNMR)和核磁共振碳谱(13C NMR)表征了化合物的结构.实验结果表明,1H-吡唑-4-甲酸的收率由文献报道的70%提高到了97.1%.     

1,4-二氢-4-芳基-3,5-吡啶二羧酸酯的合成及表征

基于二氢吡啶化合物的构效关系, 设计了一系列1,4-二氢-4-芳基-3,5-吡啶二羧酸酯新化合物. 含有易于水解基团的1,4-二氢-4-芳基-3,5-吡啶二羧酸酯类化合物在碱性条件下水解合成了重要中间体1,4-二氢-4-芳基-3,5-吡啶二羧酸单酯, 收率93%～99.8%. 该二羧酸单酯与α-溴代芳基乙酮在相转移剂催化下反应合成目标化合物, 收率74%～99%. 中间体和目标化合物经¹H NMR, ¹³C NMR, IR, MS和元素分析等确证.     

合成双酚AF的新方法

由六氟丙酮三水合物和苯胺,经缩合、重氮化、水解、Friedel-Crafts烷基化等4步反应在常压下合成了双酚 AF。首先,以五氧化二铌为催化剂,在 n (HFA•3H₂O) : n (aniline) : n (Nb₂O₅) = 2 : 1 : 0.1,回流 6 h 条件下,合成出中间体（Ⅰ）,收率高达96.3%。然后在重氮化温度为 ﹣2 ～ 2 ℃,硫酸质量分数为 14.7%,n (Ⅰ) : n (H₂SO₄) : n (NaNO₂) = 1 : 4.1 : 1.1,及水解时硫酸质量分数为 50%,n (H₂SO₄) : n (Ⅰ) = 11.0 : 1、108～112 ℃反应 1.5 ～ 2 h 的优化条件下,化合物Ⅰ经重氮化、水解后以 92.7%的高收率得到中间体 2-（4-羟基苯）六氟异丙醇（Ⅱ）;再在甲磺酸存在下,化合物Ⅱ与苯酚经Friedel-Crafts烷基化反应以 72.4% 的收率合成了目标产物双酚 AF（Ⅲ）,总收率为 64.6%（以苯胺为基准计算）。     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。