Synthesis of 2-(4-Hydroxy-6-methyl-2-oxo-2H-pyran-3-carbonyl)-6,6-dimethyl-3-phenyl-3,5,6,7-tetrahydro-2H-benzofuran-4-one Derivatives via Multicomponent Reaction

A sequential one-pot, two-step reaction for an efficient preparation of 2-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-carbonyl)-6,6-dimethyl-3-phenyl-3,5,6,7-tetrahydro-2H-benzofuran-4-one derivatives has been described. One-pot reaction of in situ–formed benzopyran-substituted pyridinium ylides with aromatic aldehydes and dimedone gives corresponding 2,3-dihydrofurans in good yields. The structures of all the newly synthesized compounds were confirmed from their analytical and spectral data.     

1-乙基-4-氧-7-甲基-1,8-萘啶-3-羧酸的合成

乙基氧甲基萘啶羧酸;缩合反应;成环反应;乙基化反应;水解反应;光谱特征     

Diastereoselective Synthesis of Nitroaldol Derivatives

Three methods are described by which diastereomerically enriched nitroaldols and their O-silylated derivatives can be prepared. threo-Nitroaldols prevail up to 10:1 over the erythro-isomers if doubly deprotonated nitroaldols 28 are quenched with acetic acid (THF/HMPT or DMPU, ? 100°) (see Scheme 5 and Table 2). O-Trimethyl- or O-(t-butyl)dimethylsilylated (TBDMSi) erythro-nitroaldols can be obtained by protonation of the corresponding lithium nitronates ( 35, 39 ) in THF at low temperature (see Schemes 6 and 7). The erythro-O-TBDMSi-nitroaldol derivatives are also formed in the fluoride catalyzed addition of TBDMSi-nitronates ( 40–45 ) to aldehydes (see Schemes 8 and 9), In the latter reaction no 1,2-asymmetric induction is observed if a-branched silylnitronates or aldehydes are employed (see 48/49 and 50/51 ) – The stereochemical course of the reactions leading to erythro-O-TBDMSi-nitroaldols follows topological rules of broad applicability (see Scheme 10); possible mechnisms are discussed. - The configuration of diasteromerically ¹³C-NMR. Spectroscopy. – Some examples of the preparation of diastereimerically enriched 1,2-aminolcohols by reduction of the correspondence nitro compounds without loss of configurational purity are described (see Schemes 11 and 12).     

Synthesis of 2-(4-Quinolyl) and 2-(3-Quinolyl) Chromone Derivatives

In continuing search of the structure-activity relationship of heterocyclic chromones, 4-quinolyl and 3-quinolyl moieties were each introduced to the C-2 position of chromones. A total of 12 quinolyl chromones were synthesized. 4-Quinolinecarboxaldehyde was condensed with 2-hydroxyacetophenones to provide the chalcones. These intermediates were then subjected to selenium dioxide dehydrogenation to yield the 6 new 4-quinolyl chromones. 3-Quinolinecarboxaldehyde was condensed with 2-hydroxyacetophenones in the presence of dilute alkali to give aldol compounds of chalcones (dehydration products of aldols). Ring cyclization of the chalcones yielded the other 6 new 3-quinolyl chromones.     

Reaction of 2-(4-Arylthiazol-2-yl)-4-chloro-3-oxobutyronitriles with Secondary Aliphatic Amines

We have obtained 2-(4-arylthiazol-2-yl)-4-chloro-3-oxobutyronitriles by acylation of 4-aryl-2-cyanomethylthiazoles with -chloroacetyl chloride. We have studied their reaction with secondary aliphatic amines, leading to formation of 4-dialkylamino-2-(4-arylthiazol-2-yl)-3-oxobutyronitriles, and also intramolecular alkylation with formation of 3-aryl-7-cyano-6(5H)-oxopyrrolo[2,1-b]thiazoles. We have determined some aspects of the tautomerism of the synthesized compounds.     

A New and Diastereoselective Synthesis of Threo-Aryl-2-Piperidylmethanol Derivatives

A diastereoselective synthesis of threo-aryl-2-piperidyl- and aryl-1,2,3,6-tetrahydro-2-pyridylmethanol derivatives is described. The stereochemistry is controlled by intramolecularly assisted NaBH₄ reduction of the intermediate carbamates 3.     

Diastereoselective Diels-Alder Reaction of 2-Thienyl and 2-Furyl Substituted 3-Propenethioamides with Electron Deficient Dienophiles

Summary. The hetero-Diels-Alder reaction of N-aryl-3-(2-thienyl)-2-propenethioamides with N-phenylmaleimide and maleimide yielded a mixture of endo- and exo-2-arylimino-4-(2-thienyl)tetrahydrothiopyran[2,3-c]pyrroles. Cycloaddition to diethyl fumarate required acylation and furnished a mixture of diastereoisomeric 5-(N-acetylphenylamino)-2,3-bis-(ethoxycarbonyl)-4-(2-thienyl)-3,4-dihydro-2H-thiopyrans. Reactions of 3-(2-furyl)-2-propenethioamides with N-arylmaleimides furnished the correspondent 2-arylimino-4-(2-furyl)tetrahydrothiopyran[2,3-c]pyrroles. In the cycloadditions of the heterodienes with N-arylmaleimides the endo-cycloadducts were formed as the major products.     

2-氰基-3-甲硫基-3-(4-甲基或6-甲基苯并[d]噻唑-2-氨基)丙烯酸酯类化合物的合成和抗病毒活性研究

以氰基乙酸和氰基乙酸乙酯为起始原料,采用活性基团拼接的方法,将苯并噻唑基团引入氰基丙烯酸酯中,设计合成了14个含有苯并噻唑基团的氰基丙烯酸酯(酰胺)类化合物3.所有化合物结构经过1H NMR,13C NMR,红外光谱和元素分析确证,并对所合成的目标化合物3进行了室内抗烟草花叶病毒(TMV)和抗黄瓜花叶病毒(CMV)活性测试.结果表明该类化合物具有一定的抗TMV和抗CMV活性.在0.5 mg/mL时,化合物3b,3c,3d对CMV表现出较好的活体治疗活性,抑制率分别为46.3％,45.1％,43.7％.     

Reaction of Lithium Derivatives of 4-Alkyl-3-morpholinones with Azomethine Compounds

Lithium derivatives of some 4-substituted 3-morpholinones react with azomethine compounds to afford 4-alkyl-2-[aryl(phenylamino)methyl]-3-morpholinones with good yields.     

Tautomeric structure of 1-Oxy-2-phenylbenzimidazole

The synthesis of 3-methyl-2-phenylbenzimidazole-1-oxide (VIII) has been accomplished. Consequently, it has been possible to establish the tautomeric structure of I as 1-hydroxy-2-phenylbenzimidazole (Ia). Contrary to recent observations on the parent 1-oxybenzimidazole (IV), I shows no tendency to exist as an N-oxide (Ib) in aqueous solution.     

2-（4-叔丁基苯氧甲基）-3-喹啉酸的闭环和去叔丁基反应

2-（4-叔丁基苯氧甲基）-3-喹啉酸（1a—1d）,在多聚磷酸（PPA）的作用下发生分子内的闭环反应和脱叔丁基反应,得到了不含有叔丁基的苯并杂卓并喹啉酮化合物（2a-2c）。它们的结构通过红外光谱、核磁共振氢谱、质谱和元素分析得以证实。     

4-羟基-3-(2-亚氨基乙基)-2H-苯并吡喃-2-酮类化合物的超声辐射合成

以乙醇为溶剂,4-羟基-3-乙酰基香豆素和胺为原料,对甲苯磺酸为催化剂,在超声波作用下合成一系列4-羟基-3-(2-亚氨基乙基)-2H-苯并吡喃-2-酮类化合物,产率62%~94%。 对产物进行了IR、1H NMR及HRMS表征,对化合物3c进行了X射线衍射分析。 该方法具有反应产率高、时间短、反应条件温和及操作简单等优点。     

KF/Al2O3催化下由芳醛、丙二腈和2-(1,2-二氢-3-亚茚基)丙二腈或2-(2,3-二氢-4H-亚萘基)丙二腈一步合成芴或菲衍生物

以芳醛、丙二腈、2-(1,2-二氢-3-亚茚基)丙二腈或2-(2,3-二氢-4H-亚萘基)丙二腈为原料, 乙醇为溶剂, 在80 ℃下以KF/Al2O3为催化剂合成了一系列芴或菲的衍生物, 该方法具有反应条件温和、产率高(72%～88%)和操作简单等优点. 产物的结构通过IR, 1H NMR和元素分析表征.     

Multicomponent Reaction for Synthesis of 2-(Indol-3-yl)pyridine Derivatives Under Microwave Irradiation

A short, practical, and efficient preparation of 2-(indol-3-yl)pyridine derivatives via a one-pot procedure of 3-cyanoacetylindole, chalcones, and ammonium acetate under microwave irradiation was described. All these compounds were obtained in good yield, and their structures were confirmed by ¹H NMR, infrared, and elementary analysis.      

固态反应合成2，4，6-三苯氧基-1，3，5-均三嗪衍生物

固态反应合成2;4;6-三苯氧基-1;3;5-均三嗪衍生物;固态反应;缩合;氰尿酰氯;三苯氧基均三嗪     

Synthesis of Quinoline Derivatives by [4+2]Cycloaddition Reaction

Synthesis of quinoline derivatives by Lewis acid catalyzed [4+2]cycloaddition was investigated.