3R-2,2-二氟-3-羟基-3-(2,2-二甲基-1,3-二氧戊环基)戊酸乙酯的合成与表征

以2,3-O-异丙亚基-D-甘油醛为原料合成抗肿瘤药物中间体3R-2,2-二氟-3-羟基-3-(2,2-二甲基-1,3-二氧戊环基)戊酸乙酯,在锌粉的催化下加入了三甲基氯硅烷使需要得到的R结构产物的比例提高,反应温度为45℃,反应时间3h,收率为72.1%以上。用IR与1HNMR对其结构进行了表征。     

磺酰胺类染料中间体的合成与表征

以乙酰苯胺、间苯二胺为主要原料,经磺酰化、酰胺化、脱乙酰基,合成了替代致癌染料中间体N,N'-1,3-苯基二-(4-氨基)苯磺酰胺,并优化了酰胺化反应条件。产物分别经元素分析、红外、质谱和核磁表征确证了结构。     

2-亚甲基-1,3-丙二醇制备工艺研究

通过单因素试验筛选出DMF作为3-氯-2-氯甲基丙烯（CCMP）碱性水解制备2-亚甲基-1,3-丙二醇（MEPO）的溶剂.水解产物采用GC-MS联用仪、GC-900气相色谱仪进行结构分析,确定CCMP水解最佳工艺条件为：转速700 r/min,w（NaOH）=10%,温度92℃,V（CCMP）∶V（NaOH）=1∶5,m（DMF）∶m（CCMP）=0.2,反应时间6 h,在此条件下CCMP的水解率可达95%.     

1,3‐Dimethoxybenzene,a newly identified component of port wine

1,3‐Dimethoxybenzene was identified by GC–O, GC–MS and Kovats indices (polar Supelcowax, 1709; non‐polar Rtx‐5MS, 1158) as a new volatile component of port wine. Sensory evaluation described this compound as having a sweet medicinal odour with hazelnut, resinous and woody notes. Respective threshold limits in model wine and port wine were 21 and 47 µg l^?1. Quantitative analysis by GC–MS, using a selected characteristic ion (m/z 138), indicated that young port wines from the 1998 vintage contained up to 3 µg l^?1 whereas ports from the 1999 vintage contained up to 20 µg l^?1. © 2002 Society of Chemical Industry     

An experimental and kinetic modeling study of cyclopentadiene pyrolysis: First growth of polycyclic aromatic hydrocarbons

The importance of 1,3-cyclopentadiene (CPD) and cyclopentadienyl (CPDyl) moieties in the growth of polycyclic aromatic hydrocarbons (PAHs) was studied using new experimental data and ab initio calculations. The experimental investigation was performed in a tubular continuous flow pyrolysis reactor under both high (24molN₂/molCPD)$(24{\text{mol}}_{{\text{N}}_2}/{\text{mol}}_{\text{CPD}})$ and low (5molN₂/molCPD)$(5{\text{mol}}_{{\text{N}}_2}/{\text{mol}}_{\text{CPD}})$ nitrogen dilutions, covering a temperature range of 873–1123 K, at a fixed pressure of 1.7 bara. At the most severe conditions up to 84% of CPD is converted, and the amount of PAHs is more than 65 wt%. Major products observed during CPD pyrolysis were benzene, indene, methyl-indenes and naphthalene, in line with previous studies. On-line GC × GC-FID/(TOF-MS) also allowed to quantify minor species (methane, toluene, styrene, phenanthrene, anthracene, etc.), never reported before at this level of accuracy. The new experimental data have been used to further analyze the role of the successive interactions of CPD, indene, and naphthalene as well as the recombination and addition reactions of their resonantly stabilized radicals and refine their kinetics. The results of the modeling study are in good agreement with existing and new experimental observations.     

Catalytic use of zeolites in the Prins reaction of arylalkenes

The Prins reaction of various arylalkenes with paraformaldehyde on different zeolites as solid acid catalysts was studied. The main product of the reaction under the experimental conditions used was found to be the corresponding 1,3-dioxane. Of the catalysts tested, beta (75) zeolite proved the most active and selective in the Prins reaction of styrene, with a selectivity of 41.4% and a conversion of 95%. Other zeolites such as USY and, especially, ZSM-5, provided much lower yields. The reactions of other arylalkenes were found to be strongly influenced by the substituents on the double bond.     

Synthesis,crystal structures and non-bonded S···S contacts with O‒H···O/O‒H···S hydrogen bonds in isomeric hydroxyphenyl-1,3-dithianes

The synthesis of isomeric hydroxyphenyl-1,3-dithianes and the role of sulfur in them to generate different engineered solids based on non-bonded O···S contacts and O?H···S hydrogen bonds are presented. With an increasing number of OH groups and dithiane rings (e.g. 2, 3), the role of O?H···S interactions becomes less prominent and the strong O?H···O hydrogen bonds along with C?H···π and π–π stacking interactions dominate the packing arrangement of the hydroxyphenyl-1,3-dithianes.     

The influence of impurities on the acid-catalyzed reaction of glycerol with acetone

The acid-catalyzed reaction of glycerol with acetone was studied in the presence of impurities that might be present in the crude glycerin of biodiesel production. These are mainly methanol, water and sodium chloride, in different amounts. The results indicated that methanol has minor effect on the glycerol conversion, whereas the concomitant addition of water and sodium chloride produces a drastic decrease of the conversion. The nature of the acid catalyst also affects the conversion in the presence of impurities. Amberlyst-15™ acid resin is more sensible to the water content than zeolite Beta. The results of the glycerol adulteration with different contaminants were compared with the reaction using a crude glycerin from a Brazilian biodiesel industrial plant.     

Reactivity of quinones for the dehydrogenation of poly(1,3‐cyclohexadiene)

The reactivity of three types of quinones (3,4,5,6‐tetrachloro‐1,2‐(o‐)‐benzoquinone (TOQ), 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), and 2,3,5,6,‐tetrachloro‐1,4‐(p‐)‐benzoquinone (TCQ)) was examined for the dehydrogenation of poly(1,3‐cycohexadiene) (PCHD) composed of 1,2‐cyclohexadiene and 1,4‐cyclohexadiene units. The order of reactivity was TOQ > DDQ > TCQ. The steric hindrance of C?O groups in the quinones appeared to be an important factor in determining their reactivity. DDQ was found to be an appropriate dehydrogenation reagent for PCHD. The reactivity of TCQ was considerably low for PCHD containing 1,2‐cyclohexadiene units. The reactivity of TOQ was too high and side reactions occurred, causing the formation of structural defects. Copyright © 2007 Society of Chemical Industry     

Supramolecular Assemblies Constructed by Cucurbituril-Catalyzed Click Reaction

Cucurbituril homologues are multi-functional macrocycles that can find applications in many areas and have numerous interesting features setting them apart from the other macrocycles. Among them, the ability of one of the cucurbituril homologues, cucurbit[6]uril (CB6), to catalyze 1,3-dipolar cycloaddition in a regiospecific fashion is truly exceptional. Using this feature, small molecules can be clicked together to form complex structures in a very efficient way. Accordingly, in this article we review recent research involving the use of CB6-catalyzed 1,3-dipolar cycloaddition or the click reaction of CB6 in the construction of supramolecular assemblies including rotaxanes, pseudorotaxanes, polyrotaxanes, polypseudorotaxanes, molecular switches, machines, and nanovalves.