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1.
研究了3-芳基-4-氨基-5-巯基-1,2,4-三唑与6-/8-取代-4-羟基喹啉-3-酸在三氯氧磷催化下的反应,制得16个的3-芳基-6-(6-/8-取代-4-氯喹啉-3-基)1,2-4,-三唑[3,4-b)-1,3,4-噻二唑,新化合物的结构通过元素分析,IR,^1H NMR和MS确定,讨论了其波谱性质。  相似文献   

2.
N-芳基-5-氨基-1,2,4-三唑-3-磺酰胺的合成   总被引:3,自引:0,他引:3  
以5-氨基-3-巯基-1,2,4-三唑为原料,经氯气氧氯化后分别用邻氯苯胺和2,6-二氯苯胺胺解,合成了两个N-芳基-5-氨基-1,2,4-三唑-3-磺酰胺,产品结构经IR和1H NMR确认。  相似文献   

3.
5-羟基-2-戊酮未经四氢吡喃保护进行Witig-Hornor反应,生成(E)-6-羟基-3-甲基-2-巳烯酸乙酯,再与TsCl反应,继而与NaI在丙酮中回流6h,制得(E)-6-碘-3-甲基-2-巳烯酸乙酯,大大缩短了碘化反应时间。  相似文献   

4.
用1-芳基-1,4-二氢-6-甲基-4-氧哒嗪-3-酰肼与取代苯基异硫氰酸酯反应合成了系列新型取代-1,4-二氢-6-甲基-4-哒嗪酮-3-酰氨基硫脲化合物,其结构经IR,1H NMR及元素分析确认,生物活性测定表明,该类化合物对烟草花叶病毒具有很高的抑制活性。  相似文献   

5.
3-(3-吡啶基)-4-氨基-5-芳胺基-1,2,4-三唑的合成与表征   总被引:6,自引:0,他引:6  
张力学  张安将  徐志雄  张自义 《合成化学》2002,10(5):415-418,421
以烟酸与芳胺为基本原料,经多步反应,制得1-烟酰基-4-芳基氨基硫脲;后者在水合肼存在下关环,合成了一系列新化合物3-(3-吡啶基)-4-氨基-5-芳胺基-1,2,4-三唑。化合物结构经元素分析、IR,^1H NMR,^13C NMR确证。  相似文献   

6.
简要综述了手性1-芳基-2,2-二甲基-1,3-丙二醇及其衍生物在不对称合成中应用和反应,包括作为手性化学位移试剂、拆分试剂、辅助剂、配体和不对称合成中间体。  相似文献   

7.
以VD2为原料制备了1α,25-二羟基维生素D3的重要中间体(1S,6R)-1-羟基-6-(1,3-苯并二硫-2-氧)-3,5-环维生素D2。其中BDT(1,3-苯并二硫-2-氧)基团的引入有利于共轭三烯系统的保护。  相似文献   

8.
陈文彬  金桂玉 《应用化学》2002,19(6):527-530
利用1,3-二芳基-2-[(1H-1,2,4-三唑-1-基)甲基]-2-丙烯-1-酮7与取代硫酚进行1,4-亲核加成,经重排得到化合物4,将化合物4用NaBH4还原,得到目标化合物5,其结构经元素分析、^1H NMR和红外光谱所确证,并测试化合物5对小麦锈病的活性,结果发现大部分化合物的杀菌活性均较低。  相似文献   

9.
在低温下用三氟化硼乙醚催化1,4-脱水-2,3-二-氧-(对迭氮基苯甲基)-α-D-核糖(ADABR)的阳离子选择性开环聚合反应,首次合成了具有1,5-开环α-结构的聚合物。单体ADABR由1,4-脱水-α-D-核糖在DMF溶剂中与对溴甲基迭氮基苯反应获得。聚合物的结构由比旋光度、1H-NMR和13C-NMR及IR谱确认。用五氟化锑为催化剂则得到了同时含有α-呋喃单元和β-吡喃单元混合结构的聚合物。研究了催化剂及其用量、聚合反应时间对聚合反应的影响,讨论了聚合反应机理。为研究1,4-脱水-2,3-二-氧-(对迭氮基苯甲基)-α-D-吡喃核糖的聚合活性以及便于测试迭氮基的含量对聚合物光刻性能的影响,还初步研究了单体ADABR与1,4-脱水-2,3-二-氧-苯甲基-α-D-吡喃核糖(ADBR)的共聚反应。从共聚物的结构分析可以认定共聚物具有1,5-α-结构,并且单体1,4-脱水-2,3-二-氧-苯甲基-α-D-吡喃核糖在实验条件下具有较高的活性。  相似文献   

10.
1,1-二氘代-3,6,9,12-四氧代-1-二十四烷醇的合成   总被引:1,自引:0,他引:1  
二缩三乙二醇在金属钠存在下与溴代十二烷反应生成3,6,9-三氧代-二十烷醇,收率86%;该醇与氯乙酸甲酯反应生成3,6,9,12-四氧化二十四烷酸甲酯,收率60%,3,6,9,12-四氧代二十四烷酸甲酯与氘代铝锂氢在乙醚中反应生成1,1-二氘代-3,6,9,12-四氧代-1-二十四烷醇,收率95%。  相似文献   

11.
Radiation-curable coatings have acquired importance, because they are environmentally-friendly (no solvent emission)and require low energy for curing, when compared to other conventional heat-curable products. UV-curable coatings performance depends on the cure quality. Suitable methods were evaluated to estimate the degree of cure applying quantitative techniques, such as differential scanning calorimetry (DSC) and differential photocalorimetry (DPC), in order to determine the residual heat of curing in UV-cured films. The results of the DPC technique showed better sensibility than DSC technique, although the use of suitable pans for the case of clear coats must be considered. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

12.
A distinct increase in skin cancer incidences is observed since the registration started in Norway in the 1950s. As UV radiation is assumed to be the main risk factor for skin cancer, hourly values of the UV irradiance were reconstructed for the period 1957–2005 for 17 of the Norwegian counties (58–70°N). For reconstruction, a radiation transfer model is run with total ozone amount and cloud information as meteorological input. Reconstructed hourly erythemally weighted UV irradiances for about 5 years are compared to measurements at four stations, two stations representing the north–south extension of Norway, and two stations at about 60°N representing the eastern inland – Western coastal contrasts. The agreement between reconstructed and measured UV varies between 0% for the northernmost site to 10–15% overestimation for the other locations. For clear sky, a reasonable agreement between reconstructed and measured data was found for all stations, while for overcast, an overestimation of 10–20% was found for all but the northernmost station. Both the cancer incidences and the reconstructed UV values have a distinct north–south increase. The UV increase towards south is mostly due to increasing solar elevation. The west to east increase is much smaller, and differences in UV are due to differences in both cloud optical thickness and total cloud amount. One additional outcome from this work is that long-term UV-data are reconstructed for Norway, data that can be used in further biological and medical studies related to UV effects.  相似文献   

13.
IntroductionSince the last decade, a large number of workshave concentrated on the photochromic behavior of in-dolinospirobenzopyran dyes[1—4]. Interest in these com-pounds has been concerned with the reversibility of thetransformation between the colorl…  相似文献   

14.
Satellite-derived UV climatology has been used to design a timetable for the outdoor UV exposure of polymeric material specimens. By pre-exposure computation, fixed time increments are transformed into a schedule with a predicted average accumulation of UV dose. The method was applied to produce a timetable for an ongoing exposure programme in a network of seven European test sites over the latitude range 28.5-67.4°N. The effect of the average seasonal variability of solar UV irradiance on the predicted accumulated UV exposure is shown to be notably diminished by the method. Relative underestimations of 5-82% of cumulative UV stress are estimated to be avoided by extensions of 6-167 days exposure durations as suggested by the adjustment procedure. Hence, more reproducible degradation data are expected to be obtainable for exposures that are not multiples of the full annual cycle of UV, especially for those with a duration <1 year.  相似文献   

15.
The shielding effect of nano TiO2 on collagen under UV radiation was investigated using UV spectrophotometry. The results indicate that the shielding of collagen under UV radiation in the presence of nano TiO2 is significant. For 2.5 wt.‐% of TiO2, there is a greater shielding effect of UV radiation than that for 0.5 wt.‐% of TiO2. In addition, this study gives hints that a novel tanning agent with a UV shielding function can be formulated by using nano TiO2.

UV absorption of collagen under UV radiation after adding 2.5 wt.‐% TiO2.  相似文献   


16.
An investigation into the influence of UV-irradiation on regenerated silk fibroin dissolved in water was carried out using UV-Vis and fluorescence spectroscopy. It was found that the absorption of regenerated silk fibroin in solution increased during UV-irradiation of the sample, most notably between 250 and 400 nm. Moreover, after UV-irradiation a wide peak emerged between 290 and 340 nm with maximum at about 305 nm. The new peak suggests that new photoproducts are formed during UV-irradiation of regenerated silk fibroin.The fluorescence of regenerated silk fibroin was observed at 305 nm, at 480 nm and at 601 nm after excitation at 275 nm. UV-irradiation caused fluorescence fading at 305 nm and at 601 nm. The increase of fluorescence was observed at 480 nm, probably due to formation of new photoproducts. After excitation at 305 nm the fluorescence of regenerated silk fibroin was observed at 340 nm and at 400 nm. UV-irradiation caused fluorescence fading at 340 nm. FTIR spectroscopy showed that primary structure of regenerated silk fibroin was not significantly affected by UV radiation. SDS-PAGE chromatography showed alterations of molecular weight of silk after UV exposure.  相似文献   

17.
C60的聚合反应是近年来C60研究的热点.Yeretzian等[1]首先在质谱中观察到了C60在激光作用下的聚合反应,我们也曾以激光真空溅射技术制备了丰富的C60与C70的聚合物[2].进一步研究还发现,C60在紫外光照射下也能聚合成膜[3].为更深入地了解C60的聚合过程,本文以扫描隧道显微(STM)技术跟踪观察了C60在紫外光辐射下所发生的形态变化.1实验部分C60吸附在Au(111)面上时能够铺展成单分子层[4].因此,我们选择Au(111)面作基底,将C60配成一定浓度的甲苯溶液滴在金表面上,待甲苯挥发后制得C60的单分子层.实验所用的紫外光源为…  相似文献   

18.
<正>A novel acid dye acid was synthesized by the condensation reaction between bromamine acid and 2-amino-6-nitrobenzothiazole and its anti-UV protection properties were evaluated.The results showed that silk dyed with this dye had very good ultraviolet radiation protection capability and excellent dyeing performance.The UV-absorption mechanism of this dye was also discussed.  相似文献   

19.
This article reports the studies of photo-oxidative behaviour of polypropylene/maleic anhydride-grafted polypropylene/organic modified montmorillonite (PP/PPgMA/OMMT) composites prepared by two different melt processing methods. Samples of pristine polypropylene (PP) and PP/PPgMA/OMMT composites were prepared in an internal mixer and in a twin screw extruder. The samples were exposed to long wavelength radiations (λ > 300 nm) for the photo-oxidation. The samples were examined by FTIR, X-ray diffraction and microscopy. Similar to the pristine (PP), it is found that the photo-oxidation process in the composites depends on the melt processing conditions, which could cause the deterioration of organic modifier of the clay and the polymer matrix. The new radicals formed in addition to the iron impurities in the montmorillonite accelerate the photo-oxidation.  相似文献   

20.
《Comptes Rendus Chimie》2015,18(10):1170-1182
Photocatalytic degradation of phenol under both UV radiation and visible light, using TiO2 (Degussa P-25) and TiO2 loaded with some transition metal ions (Co, Cu, Fe and Mo) was examined. From the series of metal loaded catalysts, Mo/TiO2 was the most efficient one. In the presence of Mo, neither TiO2 anatase/rutile fraction nor its pore size diameter has been affected. However, Mo made its surface more acidic. The percentage of phenol degradation reached under visible light was significantly lower than that under UV radiation due to the lower degree of light absorption by the catalyst surface. From the series of studied catalysts, 2 wt% Mo/TiO2 was the most efficient one. The synergetic effect between SBET, mean pore size diameter, catalyst agglomerate size, band gap, ZPC and the type of MoxOy species on TiO2 surface, depending on Mo loading, created its photocatalytic performance.  相似文献   

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