5,6—二取代—3,4—二氢—2—吡啶酮的N—烷基化反应

由四个５，６－二取代－３，４－二氢－２－吡啶酮经烷基化反应合成了九个未见文献报道的Ｎ－取代５，６－二取代－３，４－二氢－２－吡啶酮，并确定了它们的结构。     

2，4－二羟基－3－芳氨基甲基苯乙酮和8－乙酰基－3－芳基－3，4－二氢－5－羟基－2H－1，3－苯并■嗪的合成及其相互转化

研究了在氯化氢－乙醇溶液或乙醇溶液中，２，４－二羟基苯乙酮与甲醛和芳胺的Ｍａｎｎｉｃｈ反应，分别得到了５个２，４－二羟基－３－芳氨基甲基苯乙酮和５个８－乙酰基－３－芳基－３，４－二氢－５－羟基－２Ｈ－１，３－苯并嗪新化合物。用元素分析、ＩＲ、１ＨＮＭＲ、ＭＳ、ＵＶ确定了它们的结构，并成功地实现了２，４－二羟基－３－芳氨基甲基苯乙酮和８－乙酰基－３－芳基－３，４．二氢－５－羟基－２Ｈ－１，３－苯并嗪二类化合物的转化。     

2，5－二取代－1，3，4－噁二唑和N，N′－二酰基肼化合物的合成与生物活性

合成了１８种新的对称与不对称的２，５－二取代－１，３．４－　二唑及Ｎ，Ｎ′－二酰基肼化合物，用元素分析、红外光谱、核磁氢谱和质谱确定了其结构，并对它们的杀虫、抗菌活性进行了测试，发现了数个具有效强生物活性的化合物。     

磷杂螺环化合物的合成──3，9－二氢－3，9－二硫代－2，4，8，10－四氧杂－3，9－二磷杂螺环［5，5］十一烷的合成及其与α－芳基－β－硝基烯的加成反应

本文合成了３，９－二氢－３，９－二硫代－２，４，８，１０－四氧杂－３，９－二磷杂螺环－［５，５］十一烷２，研究了２在Ｎ，Ｎ－二甲基乙酰胺介质中，在氢化钠作用下与α－芳基－β－硝基烯的加成反应，得到５个新的加成产物３_（ａ－ｅ），对２及加成物３_（ａ－ｅ）的~１ＨＮＭＲ谱进行了归属，并得到元素分析和ＩＲ的证实。     

经分子内Mannich反应合成3,6—二取代—5,6—二氢—s—三唑并（3,4—b）—1, …

３－取代基－４－氨基－５－巯基－１，２，４－三唑在微量酸催化下与取代芳香醛经分子内Ｍａｎｎｉｃｈ反应合成了２９个新的３，６－二取代－５，６－二氢－ｓ－三唑并（３，４－ｂ）－１，３，４－噻二唑啉类化合物，其结构经元素分析，ＩＲ和＾１ＨＮＭＲ进行确证，并讨论了反应的立体选择性。     

1，3，4，6－四硫代戊搭烯－2，5－二酮制备含硫取代基的四硫富瓦烯的研究

以１，３，４，６－四硫代戊搭烯－２，５－二酮为原料，经偶联、醇解、烃化或醇解、烃化、偶联等步骤，制得四甲硫基四硫富瓦烯、四乙硫基四硫富瓦烃、二喹喔啉硫醚、４－甲硫基－５－甲氧甲酰硫基－１，３－二硫环戊烯－２－酮、四甲硫基乙烯和４，４＇－二甲硫基－５，５＇－二甲氧甲酰硫基四硫富瓦烯及它的异构体混合物．提出了１，３，４，６－四硫代戊搭烯－２，５－二酮醇解机理．讨论了未得到某些预期产物的原因．报道了３种四硫富瓦烯衍生物的循环伏安图及电化学性质．     

3－芳基－5，6－二氢噻唑并［2，3－C］均三唑和3－芳基－6，7－二氢均三唑并［3，4－b］［1，3］噻嗪的合成

３－芳基－５，６－二氢噻唑并［２，３－Ｃ］均三唑和３－芳基－６，７－二氢均三唑并［３，４－ｂ］［１，３］噻嗪的合成王忠义，史海健，史好新（安徽师范大学化学系，芜湖２４１０００）张自义（兰州大学化学系）三唑类化合物具有相当广泛的生物活性，如：抗菌、抗痉...     

2－氯／2－甲磺酰基－5－（2－苯基－4－喹啉基）－1，3，4－噁二唑化合物的合成及其亲核取代的研究

借处理２－羟基－５－（２－苯基－４－喹啉基）－１，３，二唑同ＰＣｌ＿５／ＰＯＣｌ＿３之间的反应合成了２－氯－５－（２－苯基－４－喹啉基）－１，３，４－二唑（３）和通过２－基－５－（２－苯基－４－喹啉基）－１，３，４－二唑的甲基化，然后氧化制得２－甲磺酰基－５－（２－苯基－４－喹啉基）－１，３，４－二唑（６）．并分别研究了３和６同胺、叠氮及肼的反应，得到２，５－二取代的二唑新衍生物．初步观察了部分化合物的抗菌活性．     

3－苯基－5－取代苯氨基－6－甲基－1，2，4－三嗪的合成

３－苯基－５－取代苯氨基－６－甲基－１，２，４－三嗪的合成陆忠娥，曾润生，席海涛（苏州大学化学系，苏州，２１５００６）关键词硫代苯甲酰胺，α－乙酰基硫代甲酰苯胺，Ｎ＇－氨基苯甲脒，３－苯基－５－取代苯氨基－６－甲基－１，２，４－三嗪１，２，４－三嗪类...     

1，5－二芳基－3，4－二取代吡唑啉的合成

以对－二（２－氯乙基）氨基苯甲醛为原料，与酮缩合生成相应的α，β－不饱和酮，再与肼反应，制备了十种新的苯氮芥取代的１．５，二芳基－３，４－二取代吡啶啉。初步测定了它们的生物活性，结果表明，化合物３ｈ，３ｉ具有较强的抗菌活性。     

Synthesis of 2,4-disubstituted N-acyl-5,6-dihydro-2-pyridones

A simple two-step procedure converts 2-substituted N-acyl-2,3-dihydro-4-pyridones to 2,4-disubstituted N-acyl-5,6-dihydro-2-pyridones.     

Addition of indolyl and pyrrolyl grignard reagents to 1-acylpyridinium salts

Certain indolyl and pyrrolyl Grignard reagents add to 1-acyl salts of 4-methoxy-3-(triisopropylsilyl)pyridine to give the corresponding 1-acyl-2-heteroaryl-2,3-dihydro-4-pyridones in good to high yield. When the 1-acyl group contained a chiral auxiliary, (+/-)-trans-2-(alpha-cumyl)cyclohexyloxy, addition of the indolyl Grignards resulted in a separable mixture of diastereomeric 2,3-dihydro-4-pyridones.     

Ring transformations of 4H-pyrans. Pyridines from 2-amino-4H-pyrans

Ring transformations of 4H-pyrans into pyridines are reported. Treatment of 2-amino-4,6-diaryl-3,5-dicyano-4H-pyrans (I) with nitrosylsulfuric acid brings about their transformation into 3,5-dicyano-4,6-diaryl-2-pyridones (VI) which can also be obtained from α-benzoylcinnamonitriles (IX) and cyanoacetamide. Similarly, 2-amino-4,6-diaryl-5-carbethoxy-3-cyano-4H-pyrans (II) lead to 4,6-diaryl-5-carbethoxy-3-cyano-2-pyridones (VII). Treatment of both series of pyrans with sulfuric acid results in the formation of the corresponding 3,4-dihydro-2-pyridones (IV and V). Reaction of pyrans II with ammonium acetate in acetic acid yields 2-amino-4,6-diaryl-5-carbethoxy-3-cyanopyridines (XII). Pyrans I undergo an entirely different type of reaction upon treatment with this reagent leading to 2,4,6-triaryl-3,5-dicyano-1,4-dihydropyridines (XV).     

Reaction of diketene with cyanothioacetamide: A convenient and regioselective method for the preparation of new 4(1H)-pyridone derivatives

The reaction of diketene with cyanothioacetamide in dry dioxane in the presence of triethylamine gives triethylammonium 3-cyano-6-methyl-4-oxo-1,4-dihydro-2-pyridinethiolate. The regioselective S-alkylation of this thiolate is a convenient method for the preparation of substituted 4(1H)-pyridones and also derivatives of thiazolo[3,2-a]pyridine and thieno[2,3-b]pyridine. The action of 2-amino-1,1,3-tricyanopropene on this thiolate leads to its transformation into a new heterocyclic system, namely, 5H-pyrido[2′,3′:4,5]thiopyrano[2,3-b]pyridine; treatment with iodine yields the oxidation product, namely, the corresponding bis(2-pyridyl) disulfide. The structure of isopropyl (3-cyano-6-methyl-4-oxo-1,4-dihydro-2-pyridinyl)thioacetate was confirmed by X-ray diffraction structural analysis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 716–725, May, 2007.     

Synthesis and reactivity of N-acyl-5- (1-hydroxyalkyl)-2,3-dihydro-4-pyridones

[structure: see text]. The Nozaki-Hiyama-Kishi reaction was used to prepare the 5-(1-hydroxyalkyl)-2,3-dihydro-4-pyridones 3. Reduction, oxidation, and substitution reactions of 3 were examined.     

Electrospray ionisation and ion-trap fragmentation of substituted 3,4-dihydro-2(1H)-pyridin-2-ones

A variety of 5-alkoxycarbonyl-4-aryl-6-methyl-3,4-dihydro-2(1H)-pyridones and hexahydrofuro[3,4-b]-2(1H)-pyridones have been investigated by electron impact (EI) and electrospray ionisation (ESI) techniques. Sequential product ion fragmentation (MS(n)) was performed to elucidate the degradation pathways for these compounds. Comparisons are made between positive and negative even-electron ions from ESI spectra and the molecular radical cations obtained under EI conditions. The data collected in this paper provide information on the strong impact that different substituents have on the ion fragmentation process.     

Prototropie et synthèses nouvelles dans la série des dihydro-5,6 hydroxy-4 pyrones-2 et pyridones-2

The multistep catalytic reduction of 6-methyl-4-hydroxy-2-pyrone allows isolation of two intermediate compounds: the biologically active parasorbic acid ( 5 ) and the 6-methyl-5,6-dihydro-4-hydroxy-2-pyrone ( 2 ). The desmotropic keto-enol equilibrium lies on the enol side, with the 4rhydroxy structure. Primary arylamines readily react with 2 , leading to corresponding 2-pyridones 8 ; with methylamine, the aliphatic intermediate 7 resulting from ring attack at the 2 position can be isolated. Also further functionnalization of both dihydropyrone and 2-pyridone is possible by selective bromination at position 3.     

Preparation and reactions of 3,4-dihydro-2H-pyran-2-ones

The Michael reaction of ethyl cinnamates with deoxybenzoin gave ethyl 3,4,5-triaryl-5-oxopentanoates which were hydrolysed to the corresponding acids. The latter could be cyclized to the respective 3,4-dihydro-2H-pyran-2-ones which underwent ring opening with several nucleophiles to the corresponding acid derivatives. However, their reaction with ammonium acetate led to the formation of 3,4-dihydro-2-pyridones. The 3,4-dihydro-2-pyrones and pyridones were dehydrogenated to the corresponding 2-pyrones and 2-pyridones by fusion with sulfur.     

Preparation of 2,6-disubstituted 2,3-Dihydro-4-pyridones: Dehydrogenation of trimethylsilyl enol ethers with palladium (ii) acetate

The oxidation of silyl enol ethers 2 with palladium(II) acetate is a convenient method for the preparation of synthetically useful 2,6-disubstituted 2,3-dihydro-4-pyridones 3.     

Reactions of α,β-unsaturated ketones with cyanoacetamide

3-Aryl-1-phenyl-2-propen-1-ones Ia-f and aroylphenylacetylenes Va-d reacted under reflux for 3 hours with cyanoacetamide in the presence of sodium ethoxide to give the corresponding 4-aryl-3-cyano-6-phenyl-2-(1H)pyridones VI. However, when ketones Ia-e were refluxed with cyanoacetamide for one hour in the presence of sodium ethoxide or piperidine, they gave the corresponding 4-aryl-3-cyano-3,4-dihydro-6-phenyl-2-(1H)pyridones IIIa-e, which upon heating with selenium gave the corresponding 2-pyridones VI. The structures of the products are based on chemical and spectroscopic evidence.