Synthesis of 3- and 5-amino-5-(3)-(pyrrol-2-yl)isoxazoles

5-Amino-3-(pyrrol-2-yl)isoxazoles were selectively prepared by the reaction of 2-(2,2-dicyano-1-ethylthioethenyl)pyrroles with hydroxylamine in methanol. Under analogous conditions, 2-(2-carbamoyl-2-cyano-1-ethylthioethenyl) pyrroles with hydroxylamine gave 5-aminoisoxazoles and their structural isomers, 3-aminoisoxazoles (3-5% yield). The latter were selectively prepared by reacting 2-(2-carbamoyl-2-cyano-1-ethylthioethenyl)pyrroles with hydroxylamine in the presence of aqueous NaOH and from the products of intramolecular cyclization of 2-(2-carbamoyl-2-cyano-1-ethylthioethenyl)pyrroles, 1-ethylthio-3-iminopyrrolizines and hydroxylamine.     

Synthesis of 2-(2-methyltetrazol-5-yl)-2,2-dinitroacetonitrile and its reaction with substituted nitrile N-oxides

A procedure of synthesis of 2-(2-methyltetrazol-5-yl)-2,2-dinitroacetonitrile has been developed and its reaction with substituted nitrile N-oxides has been investigated, proceeding by the mechanism of 1,3-dipolar cycloaddition and affording 2-methyl-5-[(1,2,4-oxadiazol-5-yl)(dinitro)methyl]-2H-tetrazoles. The latter react with KOH in ethanol forming the potassium salt of 2-methyltetrazol-5-yldinitromethane and substituted 5-hydroxy-1,2,4-oxadiazoles.     

Chemistry of hetero analogs of isoflavones 26. Synthesis of 2-alkyl derivatives of 3-(thiazol-2-yl)-and 3-(benzothiazol-2-yl)chromones

Treatment of substituted 2-(2,4-dihydroxyphenacyl)thiazole and 2-(2,4-dihydroxyphenacyl)benzothiazole with propionic and isobutyric anhydrides gives the substituted 2-ethyl-and 2-isopropyl-7-acyloxychromones. The use of pivaloyl chloride gives 1-pivaloyloxy-2-hetarylstyrene derivatives. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 835–840, June, 2008.     

Synthesis of substituted 2-(2-oxopyrrolidin-1-yl)acetamides

The reaction of chloroacetamide with 2 equiv of γ-aminobutyric acid potassium salts provides a convenient method for the synthesis of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids. Alkylation products of 2-aminoacetic and 3-aminopropanoic acid with chloroacetamide were isolated. Thermal cyclization of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids afforded 2-(2-oxopyrrolidin-1-yl)acetamides.     

Synthesis and spectral properties of 3-(2-aryl-5-methyl-1,3-oxazol- 4-yl)-2-(2,5-dimethylthiophen-3-yl)cyclopent-2-en-1-ones

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Synthesis and properties of 1,3-diphenyl-5-(benzothiazol-2-yl)-6-R-verdazyls

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Synthesis and liquid crystal properties of substituted 5-(arylcarbonyloxy)-2(p-cyanophenyl)pyrimidines

Liquid crystal p-substituted benzoates, biphenylcarboxylates, and benzoyloxybenzoates were obtained on the basis of 5-hydroxy-2-(p-cyanophenyl)pyrimidine. The development of nematogenicity by the esters due to the p-cyanophenyl grouping was noted, and the appearance of the smectic mesophase by the variation of the ring framework of the acid fragment of the molecule was investigated.Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences (RAN), Novosibirsk 630090. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 371–376, March, 1995. Original article submitted December 19, 1994.     

Synthesis and structure of N-(4,6-dimethylpyrimidin-2-yl)-2-(5-phenyl-2H-tetrazol-2-yl)acetohydrazide and 1-(4,6-dimethylpyrimidin-2-yl)-3-[(5-phenyl-2H-tetrazol-2-yl)methyl]-1H-pyrazol-5-ol

Russian Journal of Organic Chemistry - New tetrazolyl derivatives of pyrimidine were synthesized containing various linker groups. The structure of these compounds was established by NMR...     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general procedure was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones by reaction of 3-formylchromone with aroylhydrazines, transformation of the corresponding acylhydrazones into 1,3-dipoles by the action of bromine in the presence of sodium acetate, and intramolecular ring closure.     

超声辐射下合成1-[(未)取代苯酰基-3-[5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑-2-基]-硫脲

1-苯基-3-甲基-5-氯吡唑-4-甲酸与氨基硫脲在三氯氧磷中反应得到2-氨基-5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑(1), 然后分别采用超声辐射法和常规加热法与(未)取代苯甲酰基异硫氰酸酯(2)反应合成了一系列未见报到的1-[(未)取代苯酰基-3-[5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑-2-基]-硫脲(3a～3j). 化合物的结构经元素分析, IR, ¹H NMR确证.     

Synthesis of substituted 3-(3-chloro-1H-pyrazol-5-yl)quinoxalin-2(1H)ones

Synthetic strategies to gain access to all four isomers of 3-(3-chloro-1H-pyrazol-5-yl)quinoxalin-2(1H)ones with monosubstituted benzo core (i.e., compounds 8a–d) are described. Preparation of these heterocyclic compounds succeeded starting from only two different substituted 2-nitroanilines (i.e., 3-methoxy- and 4-methoxy-2-nitroaniline) in three or five steps, respectively.     

Short Synthesis of 1-(3-tert-Butyl-1-phenyl-1H-pyrazol-5-yl)-3-(5-(2-morpholinoethoxy)-2H-chromen-8-yl) Urea Derivatives

A short and efficient synthesis of 1-(3-tert-butyl-1-phenyl-1H-pyrazol-5-yl)-3-(5-(2-morpholinoethoxy)-2H-chromen-8-yl) urea derivatives (1a–c), a novel type of p38 MAPK inhibitors, is described. The Claisen thermal rearrangement of arylpropargyl ethers was employd as a key step to synthesize the chromene core. The solvent effect on the ratio of the resultant two isomers of Claisen thermal rearrangement, namely 2-methylbenzofuran and 2H-chromen, was also investigated.     

微波辐射下合成2-(未)取代苯甲酰胺基-5-(1-苯基-3-甲基-5-氯吡唑- 4-基)-1,3,4-噻二唑衍生物

分别在微波辐射和常规加热条件下, 通过2-氨基-5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑(1)与(未)取代苯甲酰氯(2a～2j)反应, 合成了一系列未见文献报道的2-(未)取代苯甲酰胺基-5-(1-苯基-3-甲基-5-氯吡唑-4-基)-1,3,4-噻二唑衍生物(3a～3j). 标题化合物的结构经元素分析, IR, 1H NMR确证.     

4-(5-喹啉-3-基-四氮唑-2-基)丁胺的合成

三苯基膦钯催化3-溴喹啉完成氰化取代制得3-氰喹啉(1);1与叠氮化钠经[2+3]环加成合成了3-(2H-四氮唑-5-基)喹啉(2);2与N-(4-溴丁基)邻苯二甲酰亚胺反应制得2-[4-(5-喹啉-3-基-四氮唑-2-基)丁基]异吲哚-1,3-二酮(3);3经肼解合成了4-(5-喹啉-3-基-四氮唑-2-基)丁胺(4...     

Synthesis and biological evaluation of novel 2-(substituted isoxazol-4-yl)-5-arylamino-1,3,4-oxadiazoles

A series of 2-(5-methyl-3-(4-chloro/trifluoromethylphenyl)isoxazol-4-yl)-5-arylamino-1,3,4-oxadiazoles were synthesized from 4-chloro/trifluoromethyl benzaldehyde, ethyl acetoacetate, hydroxylamine hydrochloride, hydrazine hydrate, and aryl isocyanate by multi-step reactions. The structures of the target compounds were elucidated by IR, ¹H NMR, MS, and elemental analysis. All these compounds were tested for in vitro antifungal activities against Botrytis cinerea and Rhizoctonia cerealis by the mycelium growth rate method, and the results indicated that some compounds displayed high antifungal activity against Botrytis cinerea.     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general method was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones starting from 3-formylchromone. This aldehyde yields acylhydrazones, from which the corresponding unstable nitrile imines are generated. These intermediates undergo intramolecular 1,3-dipolar cycloaddition.     

Synthesis of 5-(5-amino-3,6-dichloro-1,4-benzoquinon-2-yl)-2-dimethylaminothiazoles and their properties

In the reaction of 2-dimethylamino-5-(3,5,6-trichloro-1,4-benzoquinon-2-yl)thiazole with primary and secondary amines, the chlorine atom at the 5-position of the benzoquinone ring is substituted, according to the ¹³C NMR spectroscopy data, by an amino group. The chemical, spectroscopic, and electrochemical properties of 5-(5-amino-3,6-dichloro-1,4-benzoquinon-2-yl)-2-dimethylaminothiazoles were revealed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 410–415, March, 1991.     

N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)酰胺类新化合物的合成及生物活性

以N-吡啶基吡唑甲酸和2-氨基-3-甲基苯甲酸为起始原料,经由亲核加成、环化和酰化等多步反应合成了一系列结构新颖的N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)酰胺类化合物.测试了所合成化合物的杀虫及抑菌活性,结果表明,新化合物大多化合物在200 mg·L^-1浓度下对东方粘虫(Mythimna separataWalker)具有一定的杀虫活性,尤其是N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)乙酰胺(8a)和N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)-3-氯-2,2-二甲基丙酰胺(8e)致死率可达70%;部分化合物在50 mg·L^-1浓度下对油菜菌核病菌的抑菌活性相对较好(54.5%~63.6%),优于triadimefon和chlorantraniliprole;部分化合物如N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)-3,3-二甲基丁酰胺80和N-(2-(5-(3-溴-1-(3-氯吡啶-2-基)-1H-吡唑-5-基)-1,3,4-噁二唑-2-基)-4-氯-6-甲基苯基)-4-氟苯甲酰胺(8h)对苹果轮纹病菌具有中等抑菌活性.值得注意的是,化合物8e的杀粘虫活性和对油菜菌核病菌的抑菌活性都较为突出,可用作新农药创制研究的新型参考结构.     

Synthesis and permethylation of methyl 5-(2-chloropyridin-3-yl)pentanoates

Chemistry of Heterocyclic Compounds - Two methyl 5-(2-chloropyridin-3-yl)pentanoates were prepared by condensation of 1,3-bis(silyloxy)-1,3-butadienes with 2-chloropyridine-3-carboxylic acid...