N-甲基-4-羟基-5-苯基-2-吡啶酮的合成

以丙二酸和二氯亚砜为起始原料,经氯代、环合、催化氢化及烷基化反应合成了新化合物——N-甲基-5-苯基-4-羟基-2-吡啶酮,总收率38.7％,其结构经1H NMR,IR和EI-MS表征.     

4-羟基-2-吡啶酮类天然生物碱的研究进展

4-羟基-2-吡啶酮类生物碱是从植物和昆虫等内生真菌发酵液中提取分离得到的一类新型天然生物碱, 具有抗真菌、抗菌和抗肿瘤等多种生物活性. 对近年来4-羟基-2-吡啶酮类天然生物碱的分离、结构确证和全合成等进行了总结和概述, 重点介绍了Ilicilolin H, Tenellin和Sambutaxin等的全合成.     

4-羟基-2-吡啶酮的合成

以氰乙酸乙酯和原乙酸三甲酯为原料,经缩合反应制得2-氰基-3-甲氧基丁烯-2-羧酸乙酯(1);1与二甲基甲酰胺缩二甲醇缩合得2-氰基-5-(二甲氨基)-3-甲氧基-2,4-戊二烯酸乙酯(2);2在80%醋酸中环合得4-甲氧基-2-吡啶酮-3-甲酸乙酯(3);3在HBr中脱甲基和脱羧合成了4-羟基-2-吡啶酮,总收率31%,其结构经1H NMR,IR和MS确证。     

钯催化三组分烯丙基串联反应:化学专一性合成N-酰亚甲基-2-吡啶酮

N-酰亚甲基-2-吡啶酮是一类非常重要的结构单元, 广泛存在于天然产物和其它具有生物活性的化合物中. 其合成通常是通过2-羟基吡啶与相应的亲电试剂发生分子间亲核取代反应. 然而, 由于2-羟基吡啶的双亲核特性, 这一方法往往面临着N/O化学选择性难以控制的问题. 报道了一例钯催化三组分烯丙基取代反应, 化学专一性地合成难以构建的大位阻N-酰亚甲基-2-吡啶酮衍生物, 收率最高可达98%, 未见有O-烷基化副产物的生成. 该反应可以在克级规模下进行, 依然取得98%的收率. 本方法所得到的N-酰亚甲基-2-吡啶酮产物经过简单转化, 可方便地制得含吡啶酮结构的非天然氨基酸类化合物. 实验结果显示, 该三组分反应是经过一个串联的亲核取代和烯丙基取代反应而专一性地合成N-酰亚甲基-2-吡啶酮衍生物.     

4-羟基-2(1H)-吡啶酮-3-甲酰胺类冬青生菌素类似物的合成与生物活性

以反式-4-羟基肉桂酸为起始原料,经乙酰化、酰基叠氮、curtius重排、加成和环合等6步反应合成了4-羟基-2(1 H)-吡啶酮-3-甲酰胺类冬青生菌素类似物,总收率17%.随后用滤纸片扩散法对该化合物的抑菌性能进行了初步研究.实验表明,该化合物对于白色念珠菌具有较好的抑制作用,对于酵母菌抑制作用较弱,对大肠杆菌和金黄色葡萄球菌基本无抑制作用.     

多组分一锅法合成N-取代-4-羟基-2-吡啶酮

以3-氧代戊二酸二酯、N,N-二甲基甲酰胺二甲基缩醛(DMF-DMA)、伯胺为原料,L-脯氨酸为催化剂,多组分一步构建了以4-羟基-2-吡啶酮为母核的一系列化合物,并通过核磁、高分辨质谱等确证了其结构.该方法操作简便,无需中间体的分离,为4-羟基-2-吡啶酮类化合物的合成提供了便捷的方法,且溶剂参与反应,从而丰富了母体5位取代基的多样性.     

(Z)-2-(2-三苯甲基氨基噻唑-4-基)-2-[1,5-二(二苯甲氧基)-4-吡啶酮-2-基甲氧基亚胺]乙酸的合成工艺改进

以5-羟基-2-羟甲基-4-吡喃酮为原料,经羟基保护、迈克尔加成、亲核取代、Mitsunobu反应、肼解及缩合等反应合成了BAL30072关键中间体——(Z)-2-(2-三苯甲基氨基噻唑-4-基)-2-(1,5-二(二苯甲氧基)-4-吡啶酮-2-基甲氧基亚胺)乙酸,总收率23%,其结构经1H NMR和MS确证。该合成工艺已放大到公斤级规模。     

一种新型3-羟基-4-吡啶酮六齿配体TMC(BuHP)3的合成

以甲基麦芽酚为原料，1,3,5-苯三甲酰氯为三角架分子，合成了一种新的以苯环为骨架的3-羟基-4-吡啶酮六齿螯合剂TMC(BuHP)₃，其结构经¹H NMR、 FT-IR和MS表征，并通过MS分析证实了其与三价铁离子的配位。     

5-甲基-2(1H)吡啶酮的合成

以5-甲基-2-氨基吡啶为起始原料,通过重氮盐水解反应,合成了5-甲基-2(1H)吡啶酮,并对其合成工艺进行了研究,其结构经IR确证。     

光学纯的2-羟基-4-苯基丁酸乙酯的合成进展

(R)-2-羟基-4-苯基丁酸乙酯是血管紧张素转化酶抑制剂类(ACEI)药物的重要中间体.综述了其合成方法,重点介绍了最新的高效合成方法的研究进展.     

Synthesis and Antimicrobial of Some Novel-5-carbomethoxy-2-pyridone Derivatives Containing Sulfonamide Moiety

Dimethyl 4-(methoxymethylene)-2-pentenedioate 2 was selected as the starting material for the synthesis of some novel 2-pyridones containing sulfonamide moiety, which we expected to have biological activities such as bactericidal and fungicidal or other applications of certain interest.     

Reactions of 5-(het)aryl-1-ethyl-2(1<Emphasis Type="Italic">H</Emphasis> )-pyrazinones with terminal arylacetylenes promoted by microwave radiation

The reaction of 5-(het)aryl-1-ethyl-2(1H)-pyrazinones with terminal arylacetylenes, leading to a mixture of two isomeric 4-aryl- and 5-aryl-substituted 2(1H)-pyridones has been investigated. The regioselectivity of this reaction has been shown on the basis of reaction mixtures study by chromato-mass spectrometry. A crystallographic investigation of the synthesized 2(1H)-pyridones and also a forecast of their potential biological activity have been carried out.     

Microwave-assisted decarboxylation of bicyclic 2-pyridone scaffolds and identification of Abeta-peptide aggregation inhibitors

A reagent-free microwave-assisted decarboxylation procedure for carboxylic acid functionalized bicyclic 2-pyridones has been developed. This new method, based on microwave heating at 220 degrees C for 600 seconds in N-methyl pyrrolidone (NMP), proved to be practical and very efficient, resulting in decarboxylated 2-pyridones in near-quantitative yields. The decarboxylated products and the intermediate 2-pyridones in the form of carboxylic acid methyl esters and carboxylic acids were screened for their effect on Abeta-peptide aggregation. Two out of the 21 2-pyridones described in this study inhibited amyloid formation of the Alzheimer Abeta(1-40) peptide. The effect was seen even at a 4 : 1 ratio of 2-pyridone and monomeric Abeta-peptide.     

Cooperative 4-pyridone H-bonds with extraordinary stability. A DFT molecular orbital study

The N-H...O H-bonding enthalpy between 4-pyridones connected in a chain of H-bonds can achieve 23 kcal/mol for the most central H-bonds, while that between two 4-pyridones is 9.90 kcal/mol based upon DFT calculations on the counterpoise-corrected potential energy surfaces. That the range of enthalpies for N-H...O H-bonds can vary from as little as 2 to as much 23 kcal/mol depends primarily upon the polarizability of whatever internally connects the N-H and C=O within the H-bonding molecule, which are two parallel -C=C- entities in 4-pyridone. The contribution of covalent or charge-transfer interactions between the pi-systems of adjacent 4-pyridones is small.     

Approach to Polysubstituted 4-Pyridones from N-Aryl Acetoacetamides via a N to C 1,3-Acyl Migration Mediated by Sodium Persulfate

Mediated by sodium persulfate (Na(2)S(2)O(8)), a series of polysubstituted 4-pyridones were synthesized via self-condensation of N-aryl acetoacetamides, during which a novel N to C 1,3-acyl migration should be involved. The structure of 4-pyridone was unequivocally confirmed by X-ray diffraction analysis. However, the self-condensation of N-benzyl acetoacetamides under the same condition gave polysubstituted 2-pyridones instead of 4-pyridones.     

Improved procedure for the enantioselective synthesis of dihydrooxazolo and dihydrothiazolo ring-fused 2-pyridones

Improved procedures to synthesize enantioselectively analogues of a peptidomimetic scaffold with high biological relevance have been developed. Experimental design led to a general method for the preparation of dihydrooxazolo ring-fused 2-pyridones in good yields and high enantiomeric purity. The knowledge gained from this was also used to improve the microwave-accelerated synthesis of dihydrothiazolo ring-fused 2-pyridones to give complete stereo retention and high yields.     

Intramolecular rearrangement of two-ring 2,2-disubstituted 4-oxo-1,2,3,4-tetrahydropyrimidines under the influence of polyphosphoric acid

Intramolecular rearrangement of two-ring 2,3-disubstituted 4-oxo-1,2,3,4-tetrahydropyrimidines to pyridine derivatives, which takes place under the influence of polyphosphoric acid, was observed. It is shown that cycloalkanopyrimidones are converted primarily to two- or three-ring 2-pyridones and to small amounts of the corresponding 4-pyridones and 4-aminopyridines. A possible mechanism that enables one to explain the difference in the occurrence of the rearrangements primarily to 2- or 4-pyridones as a function of the absence or presence of aromatic character of the ring condensed with the pyrimidine ring is proposed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1549–1553, November, 1977.     

Retro-ene reactions in heterocyclic synthesis. II. A facile synthetic method for 4-hydroxy-2-pyridones

Schiff's bases 1 derived from ketones and t-butylamine reacted with diphenyl malonate, diphenyl methyl-malonate and diphenyl phenylmalonate to give 4-hydroxy-2-pyridones 4–6 . Schiff's bases b on reaction with trimethyl methanetricarboxylate afforded 4-hydroxy-3-methoxycarbonyl-2-pyridones 12 .     

Synthesis and evaluation of dihydroimidazolo and dihydrooxazolo ring-fused 2-pyridones—targeting pilus biogenesis in uropathogenic bacteria

Dihydrothiazolo ring-fused 2-pyridones have previously been shown to inhibit pilus assembly in uropathogenic Escherichia coli. Methods have now been developed to synthesize both dihydroimidazolo and dihydrooxazolo ring-fused 2-pyridones. To obtain the nitrogen analogs, Cbz-protected imidazolines were reacted with an acyl-Meldrum's acid derivative under acidic conditions. To prepare the oxygen analogs, a one-pot procedure was developed that allowed synthesis of dihydrooxazolo ring-fused 2-pyridones starting from acylated serine derivatives. After hydrolysis to their corresponding carboxylic acids and lithium carboxylates, biological evaluation revealed that the sulfur could be replaced by an oxygen atom and still maintains the ability to inhibit pilus assembly in uropathogenic E. coli. However, introducing a secondary amine instead of oxygen resulted in a substantial decrease in biological activity.