The optimum reaction conditions were: at present of acetic anhydride, a stoichiometric quantity of nitric acid, at room temperature for 40 minutes. Nitration of chlorobenzene gave a,50% yield of mononitro compounds, and an ortho-para isomer ratio 0.20 in product distribution of chlorobenzene mononitration.

結(jié)果表明：硅鎢酸催化性能較好免费人妻aV无码专区，催化劑載體以納米二氧化硅最好国产剧情在线一区，反應(yīng)條件中醋酸酐用量是主要影響因素；SiW_(12)O_(40)~(4-)／納米SiO_2催化劑具有強對位選擇性：在醋酸酐存在下AV超碰A∨超碰AV超碰，氯苯與等當量的硝酸室溫下反應(yīng)40分鐘a毛片在线观看，氯苯一硝化產(chǎn)物中鄰／對硝基氯苯異構(gòu)體的質(zhì)量比達0.2，產(chǎn)率可達50％国内自拍99。

The results indicate that the imprinted polymers synthesized by methacrylic acid as functional monomer exhibite the best regioselectivity, yielding up to 49.6% pare and 44.1% ortho isomer of nitrotoluene.

結(jié)果顯示分子印跡聚合物提高了甲苯的對位選擇性硝化能力99精彩视频这里有，并且以甲基丙烯酸為功能單體的分子印跡聚合物的對位選擇性最好，鄰對比為0.89亚洲二区影音先锋五月天手机。

FT-Raman and surface enhanced Raman spectra of leucine and isoleucine, the only isomer in proteinic amino acids, on the silver colloidal substrate are recorded.

報道了在蛋白質(zhì)氨基酸中唯一一對異構(gòu)體氨基酸——亮氨酸和異亮氨酸的FT-拉曼光譜和在銀膠基底上的表面增強拉曼光譜人人人人人人操人。

Resolution of racemic drugs by lipase catalysis offers an excellent technology for the preparation of single-isomer chiral drugs in organic solvent.

在有機相中，脂肪酶催化消旋體的拆分色播网址，為制備單異構(gòu)體手性藥物提供了重要的技術(shù)手段91视频日本。

With the need of pure isomer of racemic mixture increasing, more and more attentions have been paid to the chiral resolution membrane technology, which has been known as an energy-saving technology and considered as an easily scale-up chiral resolution technique.

手性拆分膜技術(shù)作為一種低能耗和易于工業(yè)放大的手性拆分技術(shù)，近年來隨著單一手性物質(zhì)需求的日益增長得到了廣泛的關(guān)注99久久99久久国产精品。

The results show high selectivity when the temperature is controlled at 50 CC , and the nitrated reaction time is 90 mm, toluene is nitrated by using 95% nitric acid as nitrating reagent at the presence of acetic anhydride, 1.0g silicotungstic acid catalyst is calcinated at 300℃ for 1.5h. The o/p (ratio of ortho to paro isomer of toluene nitration) ratio is 0.89 in product distribution of toluene nitration, lower than 1.67 using sulfonitric acid as catalyst. The yield of products is 91.6%.

結(jié)果表明免费播放毛片网址，在醋酐存在條件下，以CCl4為溶劑日韩午夜在线高清成人影片视频播放，以質(zhì)量分數(shù)為95%的硝酸為硝化劑最新黄色网站又大又粗，反應(yīng)溫度控制在50℃，反應(yīng)60 min欧美在线www， 1.0g經(jīng)300℃焙燒1.5h后的硅鎢酸催化劑一级性爱视频免费看，對甲苯表現(xiàn)出強的區(qū)城選擇性，甲苯硝化產(chǎn)物o/p值（甲苯硝化產(chǎn)物鄰位和對位異構(gòu)體的質(zhì)量比）達0.89日本88黄网站，較硝硫混酸的1.67顯著降低在线观看91香蕉国产免费，產(chǎn)物收率達到91.6%。

The present invention concerns a compound having the formula a N-oxide form, a stereochemical isomer, racemic mixture, salt prodrug, ester or metabolite thereof.

本發(fā)明涉及具有式的化合物国产性交大全、其N-氧化物形式www.99riav45、立體化學(xué)異構(gòu)體、外消旋混合物、鹽538在线国产、前體藥物欧美日韩一区二区妖精视频、酯或代謝物。

Comparisons between the experimental and computational IR spectra clarify the difference of the open- and closed-ring isomers, which indicate that it is possible to identify the tautomeric form of this diarylethene derivative using a highly selective infrared absorption band and the strong absorption at 1 705 cm-1 of the ring-closed isomer can be used in non-destructive readout by IR light.

通過紅外吸收光譜表征了該光致變色二芳基乙烯衍生物在溶液中開本一黄色视频、關(guān)環(huán)前后結(jié)構(gòu)的變化又黄又刺激的网站，并采用理論化學(xué)計算方法研究了該化合物開、關(guān)環(huán)異構(gòu)體的紅外吸收振動特性国产雏18女破苞在线播放。光致變色異構(gòu)化過程可以通過紅外吸收光譜的變化而識別欧美性爱黄色一级片视频。關(guān)環(huán)異構(gòu)體在1 705 cm

Following resolution, the following steps are performed: reduce the isomer to an alcohol, react the alcohol with triphenylmethyl chloride, ozonalyze the resulting reaction product, reduce the ozonalyzed product to yield a diol and react the diol with a methane sulfonyl compound to form-3-2-{(methylsulfonyloxy}ethoxy-4--1-butanol methane sulfonate.

拆分后，進行下一步：將異構(gòu)體還原為醇大屌色色，使醇與三苯基甲基氯反應(yīng)女人特级毛片A级毛片，臭氧化所得反應(yīng)產(chǎn)物，還原臭氧化產(chǎn)物以得到一種二醇并使所述二醇與甲烷磺跖访浪客嗳庋ú俦剖悠担基化合物反應(yīng)以形成-3-2-{(甲基磺酰基氧}乙氧基-4--1-丁醇甲烷磺酸酯91人妻互换论坛九色。

Diltiazem is an important coronary vasodilating drug and contains two chiral centers while only the (2S, 3S)-isomer has the desired activity.

地爾硫卓是重要的心血管藥物无码日韩第23页视频，在其分子結(jié)構(gòu)中含有2個手性中心，可產(chǎn)生4個立體異構(gòu)體天天舔天天色，其中只有(2S欧美A级性爱， 3S)－異構(gòu)體具有藥理活性，因此其立體選擇性合成具有很大的挑戰(zhàn)性看黄色视频网址。