新型吡啶-2-酮类衍生物的合成及生物活性

以3-氰基-5-乙酰基-6-甲基吡啶-2-酮(1a～1b)为原料,通过多步反应,合成了18种未见报道的含有均三唑并[3,4-b][1,3,4]噻二嗪或1,3,4-噁二唑啉的两类新型吡啶酮类化合物4a～4h,7a～7j,其结构经1H NMR,IR和MS及元素分析确证.利用单晶X射线衍射法测定了化合物4a的晶体结构.初步生测表明,部分化合物表现出不同的抗菌活性.     

On the reductive desulfuration of 4-and 5-nitro-2-thiophenecarboxylic acid

Conclusions We have studied several variants of reductive desulfuration of 5-nitro-2-thiophenecarboxylic acid and 4-nitro-5-ethyl-2-thiophenecarboxylic acid. The maximum yields of-aminovaleric and-aminoenanthic acid were 31% and 72%, respectively.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2102–2104, September, 1967.     

Oxazoles based on 2-amino-3-hydroxyphenalenone

2-Phenyl-and 2-(p-nitrophenyl)-4H-phenaleno[1,2-d]oxazol-4-ones were synthesized from 2-amino-3-hydroxyphenalenone.Riga Technical University, Riga LV-1048, Latvia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1065–1067, August, 1998.     

A new method for the synthesis of esters of β-thiophenecarboxylic acids

A method for the synthesis of esters of -thiophenecarboxylic acids and diethyl 3-methyl-2,4-thiophenedicarboxylate by the deamination of derivatives of 2-amino-3-ethoxycarbonylthiophene has been proposed. Ethyl tetrahydrothionaphthene-3-carboxylate has been converted by dehydrogenation on heating with sulfur into ethyl thionaphthene-3-carboxylic acid. The corresponding acids have been obtained by the hydrolysis of the esters. A number of dialkylaminoalkyl esters has been obtained from -thiophenecarboxylic acids and 3-methyl-2, 4-thiophenedicarboxylic acid via the acid chlorides.     

One-pot Synthesis of 2, 5-Disubstituted Oxazoles Using Poly[styrene（iodosodiacetate）]

2,5-Disubstituted oxazoles were prepared conveniently by treatment of aromatic α-methyl ketones and nitriles with poly[styrene(iodosodiacetate)] in one-pot process.     

2-取代苯氧乙硫基-5-吡唑基-1,3,4-噁二唑和1,ω-二(5-吡唑基-1,3,4-口恶二唑-2-硫代)烷烃的合成及生物活性

以５－吡唑基－１,３,４－口恶二唑－２－硫酮为原料,利用相转移催化法,分别与２－溴乙基取代苯基醚和１,ω－二溴烷烃反应,合成了１１个标题化合物。用元素分析,１ＨＮＭＲ和ＭＳ确定了它们的结构。初步的生物活性测试结果表明：有２个化合物具有杀菌活性,其中之一具有较好的杀虫活性     

Synthesis of triazoles and oxadiazoles from 2-aryl-3phenyl-4-amino-5-cyano-3,4-dihydropyrimidines

2-Aryl-3-phenyl-4-imino-5-cyano-3,4-dihydropyrimidines I were transformed to 1,2,4-triazoles II,IV and 1,2,4-oxadiazoles III by treatment with hydrazine, arylhydrazines or hydroxylamine in yields up to 90%.     

Solid-phase synthesis of 5-isoxazol-4-yl-[1,2,4]oxadiazoles

A library of isoxazole and 1,2,4-oxadiazole-containing diheterocyclic compounds has been prepared. Our strategy was explored in solution phase first as follows. PMB-protected 3-butyn-2-ol was deprotonated with nBuLi, acylated with methyl chloroformate, and then employed in a nitrile oxide 1,3-dipolar cycloaddition (benzaldehyde oxime in the presence of bleach) to afford the isoxazole-substituted carboxylic acid methyl ester. Ester saponification with aqueous NaOH followed by a two-step condensation with benzamidoxime gave the final isoxazole-oxadiazole diheterocyclic product in good yield. With some modifications, we next explored this chemistry on Wang resin, which led to 18 final products that were cleaved from polymer beads with 50% TFA in dichloromethane.     

Heterocycles from substituted amides. VII Oxazoles from 2-isocyanoacetamides

Certain heretofore unknown tertiary α-isocyanacetanilides 1 are reported for the first time, prepared by methods necessarily different from those employed to prepare the previously cited aliphatic α-isocyano-acetamides 2 . Like 2, 1 has been shown to readily undergo dialkylation with alkyl halides. Moreover, 1 also gives rise to oxazole and oxazoline derivatives upon reaction with acyl halides and aldehydes, respectively, resembling the similarly activated α-isocyano esters and sulfones. Further, in a demonstrable ring-chain tautomeric equilibration, apparently restricted to tertiary amides, 1 readily cyclizes, providing the only known synthesis of 5-amino-2,4-unsubstituted oxazoles 3 . In other examples 4-chloro and 4-alkyl-5-amino-oxazoles are produced. The materials and reactions are characterized, and compared with previous related studies.     

Syntheses and photophysical properties of some 5(2)-aryl-2(5)-(4-pyridyl)oxazoles and related oxadiazoles and furans

A number of 5-aryl-2-(4-pyridyl)oxazoles, a 2-aryl-5-(4-pyridyl)oxazole, the related oxadiazole and furan, several 2-(4-pyridyl)cycloalkano[d]oxazoles, and many of their quaternary salts were prepared. No single standard synthesis was effective for preparation of more than a few of the 25 free bases described; methods often unique to a base were employed. Minor variations in structure sometimes produced large differences in absorption and emission wavelengths, as well as in the magnitude of the extinction coefficient. The salts are of interest as laser dyes, scintillation fluors, biological stains, and shifters for luminescent solar concentrators.     

Synthesis of thiadiazoles,triazoles and oxadiazoles from sulfonyl acetic acids via a common route

A new class of five membered heterocycles, thiadiazoles, triazoles and oxadiazoles were prepared from sulfonyl acetic acids via acid hydrazides.     

Oxazoles revisited: On the nature of binding of benzoxazole and 2-methylbenzoxazole with the zinc and palladium halides

A synthetic and structural (X-ray) investigation into the bonding modes of benzoxazole (box) and 2-methylbenzoxazole (Mebox) ligands with halide precursors of Zn and Pd has been undertaken to clarify earlier discrepancies concerning the nature of the bonding mode(s) of the two azoles. In four structurally characterised examples, all contain the title ligands in a κ(1)N bonding motif. Calculations at the density functional level (DFT) of theory (B3LYP) confirm the ground state stability of this class of coordination for several hypothetical Pd and Zn (gas phase) compounds. The attempt to obtain suitable crystalline material of PdCl(2)(box)(2) (i.e., 5) leads to substantial complex degradation. One minor product of this process has been identified (X-ray) as the diarylformamidinato complex C(26)H(22)N(4)O(4)Pd, presumably formed via a complex combination of the decomposition products of both free box and 5.