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A simple, efficient, and green protocol for Knoevenagel condensation of Meldrum's acid and aldehydes in ionic liquid at room temperature without any catalyst is described. The reaction has been performed in different ionic liquids. The enhancement in the rate is observed in Brönsted acidic ionic liquid 1‐methylimidazolium trifluoroacetate [Hmim]Tfa, which furnishes quantitative yields with 4–30 min in most of the cases. Furthermore, ionic liquid is easily reused without any appreciable loss in activity. 相似文献
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A simple, efficient, and green protocol for synthesis of coumarin-3-carboxylic acids is described via Knoevenagel condensation of Meldrum's acid with ortho-hydroxyaryl aldehydes in [Hmim]Tfa ionic liquid, which was found to give better results than other ionic liquids. Furthermore, ionic liquid is easily reused without any appreciable loss in activity. 相似文献
4.
BingQinYANG JunLU MinTIAN 《中国化学快报》2003,14(12):1239-1241
A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and ^1H NMR spectra. 相似文献
5.
ZhangGaoLE ZhenChuCHEN YiHU QinGuoZHENG 《中国化学快报》2005,16(2):155-158
1-(α-Alkoxyalkyl)benzotriazoles are readily synthesized from three-component condensation of benzotriazole with aldehyde and alcohol in ionic liquid [Bmim]PF6. 相似文献
6.
n—Butyl Pyridinium Nitrate as a Reusable Ionic Liquid Medium for Knoevenagel Condensation 总被引:9,自引:0,他引:9
YiQunLI XinMingXU MeiYunZHOU 《中国化学快报》2003,14(5):448-450
The Knoevenagel condensation of carbonyl substrates with active methylenecompounds proceeds smoothly with ammonium acetate as catalyst in n-butyl pyridinium nitrate to afford the desired products of good purity in moderate yields. 相似文献
7.
ZhangGaoLE ZhenChuCHEN YiHU QinGuoZHENG 《中国化学快报》2005,16(2):201-204
In ionic liquid [Bmim][BF4], a series of disubstituted and trisubstituted thiourea derivatives were synthesized from phenyl and butyl isothiocyanate with a variety of amine in excellent yield. 相似文献
8.
WeiYiCHEN JunLU 《中国化学快报》2004,15(10):1146-1148
An efficient esterification of ferrocenecarboxylic acid with substituted phenols has been achieved using DCC / DMAP protocol in ionic liquids. The corresponding esters are produced in high yields. 相似文献
9.
A. Chagnes A. Tougui B. Carré N. Ranganathan D. Lemordant 《Journal of solution chemistry》2004,33(3):247-255
The shear viscosities of ionic fluids composed of ethylammonium nitrate (EAN) and methanol (MeOH) have been investigated as a function of the shear rate, the composition of the mixtures (quoted as x, the mole fraction of EAN), and the temperature (T) in the range 293–328 K. At low content of EAN (0.2 x 0.4), the solutions exhibit a non-Newtonian and a non-Arrhenius behavior. The viscosities of these solutions increase with the temperature when T > 313 K, but they are independent of the temperature at x = 0.6 and decrease for x > 0.6. Excess viscosities and excess Gibbs energies for the viscosity give evidence of the formation of strong hydrogen bonded complexes in solution for x < 0.6 and T > 318 K. For these systems, any increase in temperature favors the formation of hydrogen bonds between EAN and MeOH. 相似文献
10.
Basic Ionic Liquid: A Reusable Catalyst for Knoevenagel Condensation in Aqueous Media 总被引:1,自引:0,他引:1
GAO Guo-hua LU Liang ZOU Ting GAO Jin-bao LIU Ye HE Ming-yuan 《高等学校化学研究》2007,23(2):169-172
IntroductionThe Knoevenagel condensation of aldehydes/ketones and activated methylene compounds is one ofthe most common synthetic methods to produce func-tionalized alkenes. Theα,β-unsaturated productsobtained by this method have been widely used as th… 相似文献
11.
Electrochemical Reduction of Benzoylformic Acid in Ionic Liquid 总被引:7,自引:0,他引:7
Ionic Hquids possess a number of unique properties that makethem ideal electrolytes. Electrochical reduction of benzoyl-formic acid in room temperature ionic liquids as reaction media could be conducted with excellent performances without any ad-ditional supporting electrolyte. Electrolysis at glassy carbon electrode results in the formation of mandelic acid in 91% yield. And the electrochemical behavior of benzoylformic acid was investigated with the technique of cyclic voltammetry. 相似文献
12.
DaQingSHI JingCHEN QiYaZHUANG XiangShanWANG HongWenHU 《中国化学快报》2003,14(12):1242-1245
The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione,bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration. 相似文献
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DanQianXU ShuPingLUO BaoYouLIU ZhenYuanXU YinChuSHEN 《中国化学快报》2004,15(6):643-645
The sodium borohydride reduction of aldehydes and ketones to corresponding alcohols has been accomplished via the use of ionic liquids. The alcohols are easily obtained with excellent yields and the ionic liquid BMImBF4 could be reused. 相似文献
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On the basis of their characteristic polar nature, phase behavior and lack of vapour pressure, ionic liquids are considered as green solvents and have attracted significant attention as an alternative reaction medium for homogeneous catalysis.[1] However, the "greenness" of typical ionic liquids used in the literature consisted of halogen-containing anions (such as [AlCl4]-, [BF4]- and [PF6]-) was limited in some sense, due to the serious environment concerns if the hydrolysis stability of the anion is poor (e.g. for [AlCl4]-and [PF6]-) or thermal stability of used ionic liquid is undesired. In both cases, the additional effort is needed to avoid the liberation of toxic and corrosive HF or HCl into the environment. 相似文献
15.
Hiroyuki Matsuda Yuki Norizuki Miwako Kawai Kiyofumi Kurihara Katsumi Tochigi Kenji Ochi 《Journal of solution chemistry》2014,43(9-10):1561-1573
The object of this study was to measure the liquid–liquid equilibria (LLE) data of binary mixtures containing ionic liquids and citrus essential oil. We investigated linalool as the citrus essential oil, and 1-alkyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C n MIM]+[TFSI]?) as the ionic liquid. Firstly, the experimental apparatus and procedure for the LLE measurement of mixtures containing ionic liquids were verified by measuring the LLE of the binary mixture 1-hexyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C6MIM]+[TFSI]?) + 1-hexanol as a reference test system recommended by Marsh et al. (Pure Appl Chem 81:781–789, 2009). Next, the LLE data for IL + linalool were obtained, and the LLE data of two binary mixtures 1-butyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide ([C4MIM]+[TFSI]?) or [C6MIM]+[TFSI]? + linalool were determined. The experimental LLE data were satisfactorily represented by the non-random two-liquid model. 相似文献
16.
A multicomponent reaction of β-naphthol, dimethyl malonate, and aromatic aldehydes in the presence of NbCl5 as promoter is described. Under similar conditions, aromatic aldehydes with different substituents exhibited different behaviors than β-naphthol and dimethyl malonate. In these MCRs, 4-aryl-3,4-dihydrobenzo[f]coumarins are obtained as the major products (41–93%) and 14-aryl-14H-dibenzo[a,j]xanthenes as the minor products (1–38%). 相似文献
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Monika Karpińska Michał Wlazło Urszula Domańska 《Journal of solution chemistry》2018,47(10):1578-1596
The objective of this work was to explore the feasibility of using ionic liquids (ILs), namely N-ethyl-N-methylmorpholinium dicyanamide, [EMMor][DCA], (3-hydroxypropyl)-1-methylmorpholinium dicyanamide, [N-C3OHMMor][DCA], 1-(3-hydroxypropyl)-3-methylimidazolium dicyanamide, [N-C3OHMIM][DCA], 1-(3-hydroxypropyl)pyridinium dicyanamide, [N-C3OHPy][DCA], (3-cyanopropyl)pyridinium dicyanamide, [N-C3CNPy][DCA], and (3-cyanopropyl)methylpyrrolidinium dicyanamide, [N-C3CNMPyr][DCA] for the separation of ethylbenzene and styrene. The liquid–liquid equilibrium (LLE) data in ternary systems of {IL (1)?+?styrene (2)?+?ethylbenzene (3)} at T?=?298.15 K and ambient pressure is presented for the six ILs synthesized by us. The final chromatography analysis of the composition of tie-lines has shown that the studied ILs are not found in the raffinate phase and they show interesting results on the selectivity and solute distribution ratio for styrene extraction. A comparison of different ILs is presented for the studied separation problem. It was observed that the best separation selectivities were found for [N-C3CNPy][DCA] (SAv?=?2.38) and [N-C3OHMMor][DCA] (SAv?=?2.42) in comparison with other studied ILs in this work and those presented in the literature. While the data presented here are useful from a theoretical standpoint, the possibility of applications for these ILs in technological processes is questionable because of low solute distribution ratios, especially those calculated from the masses [N-C3CNPy][DCA] (βMAv?=?0.08) and [N-C3OHMMor][DCA] (βMAv?=?0.07). The experimental tie-lines were correlated with the non-random two liquid NRTL model. 相似文献
18.
S. H. Jayaprakash B. Satheesh Krishna S. Santhi Sudha N. Bakthavatchala Reddy P. Sreelakshmi K. Madhu Kumar Reddy 《合成通讯》2013,43(18):2083-2091
A convenient and mild procedure is developed for β-nitrophosphonates via phospha-Michael addition of phosphites to nitrostyrene at room temperature in the presence of 1,8-diazabicyclo-[5.4.0]undec-7-ene (DBU)–based ionic liquid [DBUH][OAc]. The operational simplicity, convenient workup, and reusability of the ionic liquid make this method attractive. 相似文献
19.
Davood Azarifar Behrooz Maleki Mehrnaz Setayeshnazar 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):2097-2102
An efficient and simple procedure has been developed for the synthesis of various 2-arylbenzothiazoles by acetic acid–promoted condensation of 2 -aminothiophenol with aromatic aldehydes under microwave irradiation and solvent-free conditions in high yields. 相似文献
20.
YiHU JueCHEN ZhangGaoLE ZhenChuCHEN QinGuoZHENG 《中国化学快报》2005,16(7):903-905
An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids with a-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure. 相似文献