无溶剂超声辐射下硝酸镱高效催化合成 1,4-二氢吡啶衍生物

在Yb(NO₃)₃催化下, 芳香醛、 5,5-二甲基-1,3-环己二酮、 乙酰乙酸乙酯和醋酸铵在室温无溶剂条件下经超声辐射一锅法合成了一系列1,4-二氢吡啶衍生物, 反应时间为15~35 min, 产率为86%~97%. 该方法具有条件温和、 反应时间短且产率高的优点. 催化剂Yb(NO₃)₃对环境友好且可循环使用, 为此类化合物的合成提供了一种有效的新方法.     

Synthesis of New 1,4-Dihydropyridine Derivatives Containing Thiazolyl Substituents

A series of 4-[2-methyl (or aryl) thiazole-4-yl]-2,6-dimethyl-3,5-diacetyl (or dibenzoyl) 1,4-dihydropyridines were synthesized using a modified Hantzsch reaction involving the condensation of the corresponding aldehyde with acetyl acetone or benzoyl acetone. The preparation of the corresponding aldehydes (2-methylthiazole-4-carboxaldehyde and some 2-arylthiazole-4-carboxaldehydes) was achieved by a simplified protocol of the published synthesis.     

n—Butyl Pyridinium Nitrate as a Reusable Ionic Liquid Medium for Knoevenagel Condensation

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.     

Catalytic Synthesis of Fused 1,4-Dihydropyridines and 1,4-Dihydropyridine Derivatives Using Preyssler Heteropolyacids Catalyst

An efficient and convenient method for the synthesis of 1,4-dihydropyridines from β-dicarbonyl compounds, aldehydes, and ammonium acetate and the synthesis of fused 1,4-dihydropyridines from dimedone in the presence of Preyssler heteropolyacid catalyst are reported under reflux conditions with good to excellent yields. Preyssler heteropolyacid catalyst is easily prepared, stable (up to 300 °C), reusable, efficient, green and inexpensive.     

单取代苯乙醛及其二氢吡啶衍生物的合成

以单取代苯乙酸为原料,在SOCl2/MeOH中制得甲酯;用NaBH4/MeOH将其还原制得取代苯乙醇;再用戴斯-马丁氧化剂氧化制得单取代苯乙醛;最后通过Hantzsch反应合成了9个1,4-二氢吡啶衍生物——2,6-二甲基-3,5-二乙氧羰基-4-取代苄基-1,4-二氢吡啶(4a～4i),其结构经1H NMR,13C NMR和MS表征,其中4b～4i为新化合物。     

联萘酚多氢键硫脲催化合成1,4-二氢吡啶衍生物

本文合成了三种具有多氢键的联萘酚轴手性硫脲催化剂,并将其用于催化合成1,4-二氢吡啶衍生物。结果显示,所合成的新型多氢键硫脲均表现出较好的催化作用,能有效地提高1,4-二氢吡啶衍生物的收率和对映选择性。所有新化合物结构均经过¹H NMR、¹³C NMR、IR、熔点等表征所确认。     

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.     

碱性离子液体催化“一锅法”合成1,4-二氢吡喃并[2,3-c]吡唑

在碱性离子液体氢氧化1-丁基-3-甲基咪唑([bmim]OH)催化作用下,由芳香醛、丙二腈、苯甲酰乙酸乙酯和肼或苯肼"一锅法"合成了一系列1,4-二氢吡喃并[2,3-c]吡唑化合物.实验中考察了催化剂、反应温度、催化剂用量、溶剂对反应的影响,确定了最优反应条件,给出了可能的反应机理.此外催化剂可以方便地收回,且循环使用四次其催化活性并没有显著降低.目标产物经过了1H NMR,IR,MS和元素分析确证.合成方法条件温和、反应时间短、产率高且对环境友好.     

1,4-二氢吡啶衍生物的合成方法改进

采用改进的Hantzsch反应,在氮气保护下的封闭体系中回流芳香醛、乙酰乙酸乙酯和NH4HCO3,合成了1,4-二氢吡啶衍生物(1a~1d),其结构经1HNMR,IR和元素分析确认。用XRD测定了1b的晶体结构。     

Electrochemical Oxidation of Compounds Containing 1,4-Dihydropyridine and Pyridinium Rings — Analogs of Gene Transfection Agents

A study was carried out on the electrochemical oxidation of 1,4-dihydropyridines, found as substituents in pyridinium salts, which are strong electron acceptors. The potentials for their oxidation in acetonitrile were determined. NMR spectroscopy was used to find the relative acidity of the N–H and C–H protons and the oxidation potentials were determined for the anionic products of the ionization of the N–H bond in dihydropyridine. The only product of the preparative electrolysis, in contrast to chemical oxidation, is the corresponding pyridine, namely, the oxidized dihydropyridine form.     

Ultrasound-accelerated Synthesis of 1,4-Dihydropyridines in an Ionic Liquid

Summary. Hantzsch 1,4-dihydropyridine compounds were synthesized efficiently in high yields at room temperature within short times in 1,1,3,3-N,N,N′,N′-tetramethylguanidinium trifluoroacetate as ionic liquid using ultrasound irradiation. The ionic liquid can be recovered conveniently and reused efficiently.     

One-Pot Synthesis of 1,4-Dihydropyridine and Polyhydroquinoline Derivatives via L-Proline Catalyzed Hantzsch Multicomponent Reaction under Ultrasound Irradiation

L‐Proline efficiently catalyzed the multi‐component Hantzsch reaction in EtOH at 60°C under ultrasound irradiation to afford the corresponding 1,4‐dihydropyridine and polyhydroquinoline derivatives in high yields. This method offers the advantages of neutral and mild reaction conditions, high to excellent yields of the products and simple workup.     

Design and Synthesis of 1,4-Dihydropyridine and Cinnamic Acid Esters and Their Antioxidant Properties

In this study, cinnamic acid derivatives with pyridine ring were synthesized via Hantzsch reaction in order to expand conjugation system and their antioxidant abilities were tested. According to the evaluation results of their antioxidant properties, compounds 2 and 3 have similar antioxidant activity to prevent DNA from ^·OH^- and Cu²⁺/GSH induced oxidation, demonstrating that 1,4-dihydropyridine and pyridine nucleus exhibit good resistance to oxidation while the substituents have little effect. In the meantime, the AAPH-induced oxidative DNA damage[AAPH=2,2'-azobis(2-methylpropionamidine)dihydrochloride] and trapping ABTS^+· test show that N—H bond and large conjugation systems are the pivotal parts to improve the activities of antioxidant.     

Synthesis of 1,4-Dihydropyridine Derivatives Under Solvent-Free and Grinding Conditions

This article has been retracted.     

离子液体溶剂中5-氧代-5,6,7,8-四氢苯并吡喃衍生物的一种温和有效的合成

A one-pot synthesis of a series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives via three-component coupling reactions of aldehydes, dimedone and malononitrilein room temperature ionic liquids （RTILs） without any catalyst has been reported. In the meantime, the reuse of ionic liquids and the effect of different ionic liquids as solvent on the reaction have also been investigated.     

1,4-二氢吡啶衍生物的电化学行为

1;4-二氢吡啶衍生物的电化学行为;循环伏安法     

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

1, 4-Dihydropyridine (DHP) heterocyclic ring is a common feature of various bioactivecompounds such as vasodilator, bronchodilator and antiatherosclerotic, antitumor, andantidiabetic agents1. Due to their important pharmacological activities, many methods…     

A novel TMSI-mediated synthesis of Hantzsch 1,4-dihydropyridines at ambient temperature

The synthesis of various substituted Hantzsch 1,4-dihydropyridines has been achieved using the classical Hantzsch procedure and modified Hantzsch conditions for the first time at room temperature in the presence of iodotrimethylsilane (TMSI) generated in situ in CH₃CN, in excellent yields.