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1.
结晶紫内酯(CVL)的合成可分为2步:首先合成无色结晶紫内酯(LCVL),然后将LCVL氧化成CVL.介绍了以米氏醇工艺为主的合成方法,详细研讨了米氏醇和间二甲基氨基苯甲酸的合成方法,并讨论了反应条件对反应的影响.  相似文献   

2.
结晶紫内酯(CVL)的合成分为两步:首先合成无色结晶紫内酯(LCVL),然后将LCVL氧化成CVL,综述了合成LCVL和CVL的主要方法及CVL的热变色机理。  相似文献   

3.
Ferrous, cobalt and nickel benzylidene picramates have been prepared by treating the corresponding aqueous sulphate and chloride solutions with sodium salt of 4′-dimethyIaminobenzylidene-2-hydroxy- 3.5-dinitroaniline. A metal: ligand ratio of 1:2 has been established in all these cases with the help of micro-analysis and confirmed by spectrophotometric, colorimetric and magnetic susceptibility measurements. I.R. studies of metal benzylidene picramates show N + M coordination, where M is iron, cobalt or nickel. Explosive properties of these benzylidene picramates have also been studied and it was found that the thermal stability of these benzylidene picramates increases as the atomic radius of the metal decreases. Ferrous, cobalt and nickel benzylidene picramates increased as the atomic radius of the metal decreases.  相似文献   

4.
周军  辛忠 《化工学报》2012,63(3):941-947
研究了亚苄基缩醛中羟基和亚苄基基团的个数对其在聚丙烯中溶解性和成核性能的影响,结果表明随着羟基数目的减少,亚苄基基团数目的增加,亚苄基缩醛在聚丙烯中的溶解性增强,对甲基亚苄基山梨醇、二(对甲基亚苄基)山梨醇、三(对甲基亚苄基)山梨醇和二(对甲基亚苄基)季戊四醇能够在聚丙烯结晶前从熔体中结晶析出的最低浓度分别为0.15%、0.20%、0.80%和4.00%,在此添加浓度下,成核聚丙烯的结晶温度分别提高了8.4、15.8、15.7、16.5℃,成核聚丙烯的弯曲模量提高了19.9%、35.8%、28.7%和18.6%,成核聚丙烯的雾度分别下降了12.5%、46.2%、7.4%和-17.4%。综合来看,含有两个羟基和两个亚苄基基团的二亚苄基山梨醇缩醛的成核效果最好,说明在设计亚苄基缩醛类聚丙烯成核剂时要兼顾分子结构对溶解性和成核性能的影响。  相似文献   

5.
Starting from (+)-5β-hydroxycyclopenten-2-yl-1β-acetic acid γ-lactone ( 1 ), (+)-1β-methoxycarbonylmethyl-2β, 3β-(p-nitrobenzylidene)-dioxycyclopentan-5-one ( 7 ) was prepared within 4 steps. Subsequent cleavage of the latter gives (−)-3β-hydroxy-1-methoxy-carbonylmethylcyclopent-1-en-5-one ( 8a ). Hydroxylation of the lactone ( 1 ) was found to give (+)-2β,3β,5β-trihydroxycyclopentyl-1β-acetic acid γ-lactone ( 2a ) with cis-oriented hydroxy groups in respect to the lactone ring. No formation of the trans-isomer, as has been reported earlier [4], was observed.  相似文献   

6.
Anionic solution polmerization studies of benzylidene malononitrile, benzylidene ethyl cyanoacetate and their para chloro derivtives in dimethyl formamide (DMF) as a reaction medium using pipridene as initiator under nitrogen atmosphere at 100 °C were carried out. Infrared, 1H NMR and ultraviolet-visible (UV-Vis) spectroscopic studies for the obtained polymers were investigated. The effect of γ-irradiation on PMMA films doped with 1 % of the benzylidene polymers was investigated by uv-vis spectroscopy. A change in the intensity of absorption bands with increasing irradiation dose was recorded. It is suggested that PMMA films doped with this type of benzylidene polymer can be used as dosimeter.  相似文献   

7.
Axially chiral natural products are rewarding synthetic targets, due to their wide distribution, diverse structures, and promising bioactivities. The "lactone concept" provides an efficient strategy for the regio- and stereoselective construction of even bulky biaryls. Key steps are the intramolecular coupling of the ester-prefixed molecular portions to give (mostly configurationally unstable) biaryl lactones and their stereoselective ring cleavage (usually by dynamic kinetic resolution), leading to the one or-optionally-the other atropisomeric product from the same lactone. Stereoisomeric byproducts can be recycled by recyclization back to the lactone. The broad applicability of the method is demonstrated in the total synthesis of selected representatives from five very different classes of natural biaryl products.  相似文献   

8.
氯化钾镀锌光亮剂中苄叉丙酮的作用及影响   总被引:1,自引:0,他引:1  
介绍了苄叉丙酮的性质及其作为氯化钾镀锌光亮剂的作用机理,比较了苄叉丙酮添加前后镀液和镀层的性能.实验结果表明,苄叉丙酮可以增大镀液的极化作用,提高镀层的光亮度和整平性.  相似文献   

9.
Relationship between molecular structure and nucleation of benzylidene acetals in isotactic polypropylene was investigated by differential scanning calorimeter and two‐dimensional correlative infrared spectra. The results indicated that benzylidene acetals can dissolve into isotactic polypropylene at high temperature and form nuclei to induce the crystallization of isotactic polypropylene at low temperature. The solubility of benzylidene acetals depend on the number of hydroxyl, but the nucleation of benzylidene acetals depend on the number of benzylidene, which could interact with methyl of isotactic polypropylene. The latter intermolecular interaction makes the infrared absorbance of methyl change before that of skeleton C‐C and methine of isotactic polypropylene in the induction period of crystallization. The order is opposite in the induction period of crystallization of virgin isotactic polypropylene. Then, new efficient nucleating agents for isotactic polypropylene can be designed by changing the number of hydroxyl and benzylidene of benzylidene acetals. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers  相似文献   

10.
祁刚  屠树滋 《精细化工》2007,24(7):714-716
运用拼合原理并根据构效关系研究结果,设计了香豆素噻唑烷二酮类化合物,合成方法是以甲基取代的香豆素为原料,经NBS溴化后,再与5-(4-羟基苄叉)-噻唑烷-2,4-二酮在NaH作用下缩合得到,其中中间体5-(4-羟基苄叉)-噻唑烷-2,4-二酮是由噻唑烷二酮与对羟基苯甲醛在哌啶催化下缩合得到,共合成了5-[4-(香豆素-7-亚甲氧基)苄叉]-噻唑烷-2,4-二酮、5-[4-(4-甲基香豆素-7-亚甲氧基)苄叉]-噻唑烷-2,4-二酮、5-[4-(香豆素-6-亚甲氧基)苄叉]-噻唑烷-2,4-二酮、5-[4-(7-甲氧基香豆素-4-亚甲氧基)苄叉]-噻唑烷-2,4-二酮、5-[4-(3-溴香豆素-7-亚甲氧基)苄叉]-噻唑烷-2,4-二酮、5-[4-(3-溴-4-甲基香豆素-7-亚甲氧基)苄叉]-噻唑烷-2,4-二酮6个香豆素噻唑烷二酮类化合物,结构均经IR1、HNMR、MS确定,两步反应合成目标化合物总产率分别为10.4%、13.1%、7.1%、16.0%、22.0%、18.0%。  相似文献   

11.
The inhibiting action of 4-amino-antipyrine (AAP) and its schiff bases 4-[(benzylidene)-amino]-antipyrine (BAAP), 4-[(4-hydroxy benzylidene)-amino]-antipyrine (SAAP) and 4-[(4-methoxy benzylidene)-amino]-antipyrine (AAAP) which are derived from 4-amino-antipyrine with benzaldehyde, salicylaldehyde and anisaldehyde, toward the corrosion behavior of mild steel in 1 M HCl solution was studied using weight loss, potentiodynamic polarization, electrochemical impedance and FT-IR spectroscopic techniques. Although AAP was found to retard the corrosion rate of mild steel, the synthesized schiff base compounds were seen to retard the corrosion rate very effectively. The inhibitor efficiencies calculated from all the applied methods were in good agreement and were found to be in the order: AAAP > SAAP > BAAP > AAP.  相似文献   

12.
针对现有美罗培南侧链中间体(硫醇内酯)制备工艺成本较高、反应路线复杂、副反应多、收率及粗品纯度较低等缺点,研究了一种简便制备硫醇内酯的方法,通过将M1[(2S,4R)-2-羧基-1-(4-硝基苄氧羰基)吡咯烷)]羧基活化、羟基活化和硫化成环合为一锅法以及添加相转移催化剂法制备硫醇内酯,再进行开环反应得到美罗培南侧链。研究了氯甲酸异丙酯、甲基磺酰氯(MsCl)、三乙胺(TEA)、Na2S·9H2O和三类相转移催化剂[聚乙二醇类(PEG)、季铵盐类和冠醚类]的投料摩尔比对制备硫醇内酯收率和纯度的影响。制备硫醇内酯时加入相转移催化剂既可以加快反应的速率,又可以提高产品纯度及收率。nM1n氯甲酸异丙酯nMsClnNa2S·9H2OnCTEA(羧基活化时所加TEA)nHTEA(羟基活化时所加TEA)n催化剂为1∶1∶1.3∶1.3∶1.3∶1.2∶(0.07~0.16),羧基活化和羟基活化反应温度均为-30~-17℃,羧基活化和羟基活化反应时间分别为15min、30min;硫化成环从-30~-17℃升温到0℃,升温反应时间为30min;回流温度为40℃,回流时间165min。硫醇内酯收率为98.4%,纯度为98.3%。  相似文献   

13.
The concave pyridine 2a has been synthesized in 61% yield in two macrocyclization steps. After deprotection to give 2b , the concave pyridine has been attached to a Merrifield resin, and the resulting polymer 10 containing 0.3 mmol 2 /g has been used as a selective acylation catalyst for the addition of propane‐1,2‐diol ( 11 ) and the glucose derivative 14a to diphenylketene ( 12 ) to form selectively 2‐hydroxypropyl diphenylacetate ( 13a ) (selectivity 13a / 13b : 11:1) and methyl 4,6‐0‐benzylidene‐2‐diphenylacetyl‐α‐D‐gluco‐pyranoside ( 14b ), (selectivity 14b / 13c : 29:1), respectively. After successful applications in batch reactions, the selective addition of 11 to 12 has also been carried out in a flow reactor filled with the polymeric catalyst 10 .  相似文献   

14.
以对甲苯磺酸为催化剂,用1,1,1-三羟甲基乙烷(THME)与苯甲醛在四氢呋喃中反应,合成出2,2-二羟甲基缩苯甲醛丙醇;再以三乙胺作缚酸剂,用2,2-二羟甲基缩苯甲醛丙醇与甲基丙烯酰氯反应合成出甲基丙烯酸(2,2-二羟甲基)丙酯的缩苯甲醛衍生物,再与盐酸反应得到甲基丙烯酸(2,2-二羟甲基)丙酯。用核磁共振氢谱(1H NMR)证明了所合成化合物的结构。  相似文献   

15.
The radiation‐induced graft polymerization of N‐vinyl‐2‐pyrrolidone onto low‐density polyethylene films was conducted with γ radiation by a simultaneous technique. The grafted copolymer was modified with cinnamonitrile or benzylidene malononitrile. The modified and grafted films were amidoximated with hydroxylamine hydrochloride in a basic medium. However, during amidoximation, the benzylidene malononitrile was cyclized to yield isoxazole ring through an addition to the nitrile group in its structure, whereas the nitrile groups of cinnamonitrile were converted into amidoxime groups. The swelling behavior of the grafted copolymers and copolymers grafted and modified either with cinnamonitrile or benzylidene malononitrile was studied. Amidoximated and grafted films and copolymer–metal complexes of Cu(II) were prepared and characterized. The effect of the isoxazole ring on polymeric materials was also investigated. These films were characterized with different analysis techniques, such as infrared, ultraviolet (UV), elemental analysis, energy‐dispersive spectroscopy, and electron spin resonance (ESR). The UV and ESR analyses revealed that the geometric structure of Cu(II) was square‐planar. Scanning electron microscopy was used to examine the grafted and modified films to determine the changes in the surface morphology. Morphological changes clearly appeared for both complexed and isoxazole films because of the increase in their crystallinity. The thermal stability of different films was investigated with thermogravimetric analysis. The improvement of the copolymer by modification with cinnamonitrile derivatives showed great promise for some practical applications, such as metal recovery by complexation or the use of isoxazole in medicine. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1189–1197, 2005  相似文献   

16.
Polystyrene terminated with benzyl alcohol units was employed as a macroinitiator for ring‐opening polymerization of ε‐caprolactone and L ‐lactide to yield AB‐ and ABC‐type block copolymers. Even though there are many reports on the diblock copolymers of poly(styrene‐block‐lactide) and poly(styrene‐block‐lactone), this is the first report on the poly(styrene‐block‐lactone‐block‐lactide) triblock copolymer consisting of two semicrystalline and degradable segments. The triblock copolymers exhibited twin melting behavior in differential scanning calorimetry (DSC) analysis with thermal transitions corresponding to each of the lactone and lactide blocks. The block derived from ε‐caprolactone also showed crystallization transitions upon cooling from the melt. In the DSC analysis, one of the triblock copolymers showed an exothermic transition well above the melting temperature upon cooling. Thermogravimetric analysis of these block copolymers showed a two‐step degradation curve for the diblock copolymer and a three‐step degradation for the triblock copolymer with each of the degradation steps associated with each segment of the block copolymers. The present study shows that it is possible to make pure triblock copolymers with two semicrystalline segments which also consist of degradable blocks. Copyright © 2009 Society of Chemical Industry  相似文献   

17.
A new class of poly(benzylidene phosphoramide ester)s containing a photoreactive benzylidene chromophore in the main chain were synthesized from bis(4-hydroxy-3-methoxy benzylidene) acetone with various substituted N-aryl phosphoramidic dichlorides by an interfacial polycondensation technique. The synthesized polymers were characterized by inherent viscosity, IR, and 1H-, 13C-, and 31P-NMR spectroscopy. The molecular weights of these polymers were determined by gel permeation chromatography. These polymers were studied for their thermal stability and photochemical properties. Thermal properties were evaluated by thermogravimetric analysis and differential scanning calorimetry. It was found that halogen-containing polymers show a higher thermal stability than that of nonhalogenated polymers. The photocrosslinking property of these polymers was studied by ultraviolet spectroscopy. The photoreactive benzylidene chromophore in the main chain dimerizes via 2π + 2π cycloaddition reaction to form a cyclobutane derivative and leads to crosslinking. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2151–2157, 1997  相似文献   

18.
采用SEM,XRD和赫尔槽等方法研究了苄叉丙酮和明胶对酸性镀锡层形貌、沉积速率和分散能力的影响。当苄叉丙酮的质量浓度较低时,镀层微粒呈柱状,结晶大小极不均匀。随着其质量浓度的增大,镀层形貌向片状转变,且晶粒尺寸显著细化。当明胶的质量浓度较低时,镀层微粒呈片状紧密地吸附在基体表面,导致结晶不太均匀。随着其质量浓度的增大,镀层晶粒进一步细化均匀。随着苄叉丙酮和明胶的质量浓度的增大,镀层沉积速率先增大后减小,适宜的苄叉丙酮和明胶的质量浓度分别为0.01 g/L和1 g/L。在适宜的条件下施镀15 min,所得镀层在(112)晶面择优取向,结晶细致均匀、光滑平整,为半光亮,镀层沉积速率和镀液分散能力分别达到4 341 mg/(dm2.h)和98.08%,可用于印刷线路板酸性镀锡。  相似文献   

19.
Colour formers are important as functional dyes for imaging and data recording systems. Metal complexes of substituted arylsulphonic acids or arylcarboxylic acids have been synthesised to prolong the life of coloured species derived from crystal violet lactone. The suppressing effect of these compounds towards photofading was investigated on cellulose. It was found that zinc and nickel salts of 2,6-dihydroxybenzoic acid and its derivatives can be applied as effective stabilisers against the fading of crystal violet lactone. The protecting effect of phenyl esters against fading was also examined.  相似文献   

20.
Polymer Bulletin - (2E,6E)2,6-Bis(4-amino benzylidene)cyclohexanone (BABC) was synthesized and used as a curing agent for tetrafunctional epoxy resin of bisphenol-C-formaldehyde (EBCF). Cured resin...  相似文献   

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