二茂铁基1,4-Dihydropyridine类似物的合成

A series of ferrocenyl 1,4 dihydropyridines were synthesized with high yields by a one pot cyclocondensation of formylferrocene,β ketoester and urea(or methyl 3 aminocrotonate) on the surface of SiO 2 under microwave irradiation without solvent.All products were characterized by EA,IR, and 1 HNMR.

Multicomponent Reaction in Ionic Liquid: A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

An efficient and green method for the synthesis of 1, 4-dihydropyridine derivatives mediated in an ionic liquid, [bmim][BF4], through a four-component condensation process of aldehydes, 1, 3-dione, Meldrum＇s acid and ammonium acetate is disclosed in this paper.

Oxidative aromatization of Hantzsch 1,4-dihydropyridines by aqueous hydrogen peroxide-acetic acid

A simple method for the oxidative aromatization of Hantzsch 1,4-dihydropyridines to the corresponding pyridines is achieved by using hydrogen peroxide as green oxidant and acetic acid as catalyst in aqueous solution.

Pd/C-catalyzed selective reduction of aromatic azides with Hantzsch 1,4-dihydropyridine

The reagent combination of Hantzsch 1,4-dihydropyridine and Pd/C was found to be an efficient reducing system for the selective reduction of aromatic azides.

An Improved and Efficient Preparation of the Chiral NAD(P)H Model (S_s)-1-Benzy1-3-(p-tolylsulfinyl)-1,4-dihydropyridine

An improved procedure for the preparation of China, BAD(P)H model. (S_s)- 1 -benzyl-3- (p-tolylsulfinyl)-1.4-dihydropyridine with satisfactary chemical yield and excellent enantiopurity is reported.

微波辅助溶胶-凝胶法合成MgO纳米粒子及其催化合成Hantzsch1,4-二氢吡啶性能(英文)

A microwave-assisted sol-gel method was employed for the preparetion of nano-sized MgO particles using Mg(NO 3)2·6H2O as precursor and deionized water as solvent.The sample calcined at 500℃ had a high specific surface area of 243.2m2/g and particles sizes from 9.5to10.5nm.For comparison,MgO nanoparticles were also synthesized without microwave irradiation.X-ray diffraction (XRD) characterization showed the formation of smaller particles after microwave irradiation.The structure and morphology of the MgO particles were analyzed by N2 adsorption-desorption,XRD,scanning electron microscopy,and transmission electron microscopy.Their catalytic behavior was studied with the one-pot synthesis of Hantzsch1,4-dihydropyridines from the reaction of aromatic aldehydes,ethyl acetoacetate,and ammonium acetate.The MgO nanoparticles have high catalytic activity and gave the desired products in good to high yields.The catalyst can be easily recovered by filtration and was used at least three times with only a slight reduction in its catalytic activity.

硅胶硫酸:一种在温和及无溶剂条件下一锅法合成1,4-二氢吡啶的高效多相催化剂(英文)

A series of 1,4-dihydropyridines have been prepared by a one-pot condensation of aldehydes,ethyl acetoacetate,and ammonium acetate in the presence of a heterogeneous catalyst silica sulfuric acid at room temperature under solvent-free condition. This new protocol has the advantage of short reaction time and excellent yields,and is an environmentally benign route to the synthesis of 1,4-dihydropyridines.

Co纳米粒子催化无溶剂条件下一锅四组分法高效合成1,4-二氢吡啶衍生物(英文)

A straightforward and general method has been developed for the synthesis of C5-unsubstitiuted 1,4-dihydropyridines by a reaction using dimedone, acetophenone, aromatic aldehydes, and ammonium acetate in the presence of a catalytic amount of Co nanoparticles as a heterogeneous and eco-friendly catalyst with high catalytic activity at room temperature under solvent-free conditions. This catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. In addition, it is very interesting that when using Co nanoparticles as a catalyst, spatially-hindered aldehydes such as 2-methoxy-, 2-fluoro-, and 2-chloro-aldehydes are suitable for this reaction.

Synthesis, Crystal Structure and Biological Activity of Diethyl 1,4-dihydro-2,6-dimethyl-4-(4-methyl-1,2,3-thiadi azol-5-yl)pyridine-3,5-dicarboxylate

The title compound diethyl 1,4-dihydro-2,6-dimethyl-4-（4-methyl-1,2,3-thiadiazol- 5-yl） pyridine-3,5-dicarboxylate （C16H21N3O4S, Mr = 351.42） was prepared by the Hantszch reaction with 4-methyl-1,2,3-thiadiazole-5-formaldehyde, ethyl acetoacetate and ammonium acetate in the presence of aluminum chloride in alcohol, and its structure was characterized by IR spectra, 1H-NMR, EA, and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic system, space group P21/n with α= 11.300（2）, b = 12.771（3）, c = 12.826（3） ？, β = 96.55（3）o, V = 1839.0（6） ？3, Z = 4, Dc = 1.296 g/cm3, μ（MoKa） = 0.71073 mm-1, F（000） = 744, R = 0.0981 and wR = 0.1994. X-ray diffraction result shows that the torsion angles of N（1）–C（2）– C（3）–C（4） and C（2）–C（3）–C（4）–C（8） are 178.9（3）° and –130.3（3）°, respectively. All rings in the title compound are non-planar. The bioassay results indicate that the title compound has good fungicidal activity, good antivirus activity against tobacco mosaic virus and certain extent of insecticidal activity against Mythimna separata.

Synthesis and Crystal Structure of Tetraethyl syn-1,5,8,8bβ-Tetrahydrocyclobuta[1,2-b:3,4-b']dipydine-3,4aβ,7,8aβ(4H,4bβH)-tetracarboxylate

The synthesis of syn-photodimer from 1,4-dihydropyridine without 4-aryl was studied, and its single crystal was obtained （C22H30N2O8, Mr= 450.48）. It crystallizes in monoclinic, space group P21/c with a = 11.937（2）, b = 20.913（4）, c = 9.763（2） A,β = 108.46（3）°, V= 2311.9（8） ,A^3, Z= 4, Dc = 1.294 g/cm^3,/7（000） = 960,μ = 0.099 mm^- 1, R = 0.0640 and wR = 0.1464 for 4077 unique reflections with 1598 observed ones （I 〉 2σ（I）. It is shown that the whole molecular structure of the title compound is a twist-boat conformation, and the two double bonds have a trend of potential intramolecular reaction under high-energy irradiation.

Crystal Structure and Bovine Serum Albumin Binding Studies of Methyl 4-(2,4-Dichlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate

The title compound, methyl 4-(2,4-dichlorophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate(C_(20) H_(21)Cl_2NO_3, 1) was synthesized and the crystal structure was —determined by single-crystal X-ray diffraction. It crystallizes in tetragonal system, space group P421 c with a = 16.076(3), b = 16.076(3), c = 14.750(2) ?, V = 3811.8(14) ?3, Z = 8, R = 0.0377 and wR = 0.0845. The interactions between compound 1 and bovine serum albumin(BSA) were investigated using fluorescence spectroscopy. The results revealed that compound 1 can effectively quench the intrinsic fluorescence of BSA by static quenching mechanism. The thermodynamic parameters revealed that the action forces between compound 1 and BSA were mainly van der Waals forces and hydrogen bonds. According to F?rster's non-radioactive energy transfer theory, the binding distance between compound 1 and BSA had been determined. Furthermore, the synchronous fluorescence showed that compound 1 has few effects on the microenvironment and conformation of BSA in the binding process.

Visible-Light-Mediated Photocatalyst-Free Hydroacylation of Azodicarboxylic Acid Derivatives with 4-Acyl-1,4-dihydropyridines

A visible-light-enabled,photocatalyst-free hydroacylation reaction of azodicarboxylic acid derivatives was described.This radical conjugate addition(RCA)protocol relied on the dual role of 4-acyl-1,4-dihydropyridine(acyl-DHP)reagents that besides being as radical reservoirs,they also enabled the conversion of radical adducts to anion intermediates via reduction.Under“catalyst-oxidant-additive free”conditions,a wide range of structurally different acyl hydrazide products were readily obtained in 56%—99%yields.The utility of this transformation was further demonstrated by the scale-up synthesis and downstream derivatization.

二氢吡啶对尼罗罗非鱼生长作用及血清T_3、T_4水平的影响

二氢吡啶以三个不同水平(0、50、100mg/kg)添加饲喂雄性尼罗罗非鱼33d,探讨二氢吡啶的适宜添加水平及其对血清T3、T4水平的影响。结果表明,添加二氢吡啶(50、100ng/kg)可使日增重分别提高11.9%(p=0.063)、6.8%,体重特定生长率提高12.6%(p<0.05)、8.7%,饵料系数分别较对照组降低9.0%、6.9%,但对试验鱼平均存活率及背侧肌组成无影响;试验末,50mg/kg组血清T3水平极显著高于对照组(2.449±1.119,1.757±0.555p<0.01),T4均处于不可测水平。

Application of Enzymatic Promiscuity in Pharmaceutical Synthesis:Papain-catalyzed One-pot Synthesis of 1,4-Dihydropyridine Calcium Channel Antagonists and Derivatives

A new method for the synthesis of 1,4-dihydropyridine(1,4-DHP)calcium channel antagonists felodipme, nitrendipine and their derivatives via papain-catalyzed three-component reactions of aldehyde,methyl acetoacetate and ethyl 3-aminocrotonate was developed.Operational simplicity,mild reaction conditions and eco-friendliness are the key features of this protocol.

n-Butyltriphenylphosphonium peroxodisulfate:A cheap and efficient reagent for the aromatization of Hantzsch 1,4-dihydropyridines

Different 4-substituted 1,4-dihydropyridines have been oxidized to pyridine derivatives by n-butyltriphenyl phosphonium peroxodisulfate in acetonitrile solution at reflux condition. Formation of two kinds of products has been observed depending on the type of 4-substituent.

LiBr as an Efficient Catalyst for One-pot Synthesis of Hantzsch 1,4-Dihydropyridines under Mild Conditions

A simple, inexpensive and efficient one-pot synthesis of 1,4-dihydropyridines has been accomplished via lithium bromide-catalyzed Hantzsch three-component condensation reaction of an aldehyde, α,β-ketoester and ammonium acetate in acetonitrile at room temperature in good to excellent yields. The present protocol is applicable to wide range of substrates including aliphatic, aromatic and heterocyclic aldehydes affording 1,4-dihydropyridines.

An Efficient, Three-component One-pot Preparation of 1,4-Dihydropyridines Containing Novel Substituted Pyrazole under Sulfamic Acid Catalysis

An efficient approach to 1,4-dihydropyridines containing novel substituted pyrazole is achieved via threecomponent reaction of pyrazolyl aldehyde, β-ketoester, and ammonium acetate in one-pot under sulfamic acid catalysis.

Synthesis of Some New 1,4-Dihydropyridine Derivatives through a Facile One-pot Hantzsch Condensation Catalyzed by Triethylamine

A facile and efficient synthesis of new 1,4-dihydropyridine derivatives was reported via Hantzsch three-com- ponent condensation reaction of aldehydes or formylphenylboronic acids, ethyl acetoacetate, and ammonium acetate in the presence of a catalytic amount of triethylamine under solvent-free conditions. The method described here of- fers several advantages including high yields, short reaction times, and simple work-up procedure.

An efficient three-component domino synthesis of difluoromethyl-containing 1,4-dihydropyridines under solvent and catalyst free conditions

The difluoromethyl-containing Hantzsch 1,4-dihydropyridines were synthesized in good yields by a one-pot cyclocondensation of ethyl difluoroacetoacetate (EDFAA),a variety of aromatic aldehydes and ammonium acetate under solvent and catalyst free conditions.The comparison of reaction conditions and products was made among the different 1,3-carbonyl substrates (ethyl acetoacetate,ethyl difluoroacetoacetate and ethyl trifluoroacetoacetate) for the Hantzsch reaction.

Silica-supported Perchloric Acid Catalyzed One-pot Synthesis of 1,4-Dihydropyridines

An environmentally friendly and highly efficient procedure for the preparation of 1,4-dihydropyridines by the reaction between a,β-unsaturated aldehydes, aromatic amines and β-keto esters in the presence of silica supported perchloric acid is described.