Synthesis and Modification of Hetero-Fused Pyrazoles Derived from Methyl 1-(2-Oxo-2-phenylethyl)-3-phenyl-1H-pyrazole-5-carboxylate

Russian Journal of Organic Chemistry - A modified procedure has been proposed for the synthesis of 2,7-diphenyl-5,8-dihydro-4H-pyrazolo[5,1-d][1,2,5]triazepin-4-one, and the possibility of...     

Synthesis of 5-Chloroisoxazoles Derived from 2,2-Dichlorovinyl Ketones

Russian Journal of Organic Chemistry - The reactions of 2,2-dichlorovinyl ketones with hydroxylamine hydrochloride give the corresponding oximes. The subsequent heterocyclization of the latter...     

从(-)-莽草酸出发合成(3R,5R)-3,4,5-三苯甲酰氧基环己酮

报道了一种合成手性中间体(3R,5R)-3,4,5-三羟基环己酮的新方法。首次以(-)-莽草酸为起始原料,经苯甲酰化、双键氢化、选择性还原甲酯、羟基碘代、碘代烃消除、双键双羟化、片哪醇断裂等步骤,以44.9%的总收率合成了(3R,5R)-3,4,5-三苯甲酰氧基环己酮,所有化合物的结构经¹H NMR、 ¹³C NMR、 IR及MS等确证。      

Syntheses of 1-(3-oxoalkyl)indole-2-3-diones

Hydration of the triple bond in 1-(alkyn-2-yl)indole-2, 3-diones under Kucherov reaction conditions takes place under the orienting influence of the nitrogen atom with formation of an oxo group exclusively at the -carbon atoms.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 483–488, April, 1996.     

5-[5-(3-吡啶)-2H-四唑亚甲基]-2-芳酰氨基-1,3,4-噻二唑的合成

正如前文报道,l,3,4—噻二唑类杂环之所以有除草,植物生长调节,驱虫以及消炎等多种生物活性,无疑起因于噻唑母核。尽管母核上取代基不起主导作用,但它作为辅助基,在改善分子溶解性以及药效方面所产生的影响是不能忽略的。因而深入研究各种生物活性基团导入噻二唑环母核以制得多结构单元聚集于同一分子中的噻二唑新衍生物,对于开发多功能新药具有一定的理论意义和实际价值。     

Oxidation of 3-(2,2-Dialkylhydrazino)- 1,1,2,2-tetracyano-5-R-cyclopentanes

Oxidation of 3-(2,2-dialkylhydrazino)-1,1,2,2-tetracyano-5-R-cyclopentanes were converted into 3-(2,2-dialkylhydrazono)-1,1,2,2-tetracyano-5-R-cyclopentanes by treatment with potassium permanganate in a sulfuric acid or acetic acid solution and into 1-dialkylamino-5,5,6,6-tetracyano-4-R-piperidin-2-ones by treatment with nascent HOCl or HOBr.     

Highly regioselective synthesis of 1-aryl-3 (or 5)-alkyl/aryl-5 (or 3)-(N-cycloamino)pyrazoles

[Reaction: see text]. An efficient highly regioselective protocol for the synthesis of isomeric 1,3-diaryl (or 1-aryl-3-alkyl) and 1,5-diaryl (or 1-aryl-5-alkyl)-5 (or 3)-(N-cycloamino)pyrazoles has been reported by cyclocondensation of common alpha-oxoketene N,S-acetal precursors with arylhydrazines by variation of reaction conditions.     

Convenient Syntheses of Functionalized Dialkyl Ketones and Alkanoylsilanes: 1-(Benzotriazol-1-yl)-1-phenoxyalkanes as Alkanoyl Anion Equivalents

(Benzotriazol-1-yl)-1-phenoxyalkanes 10, prepared by two-step transformations of the corresponding aldehydes, are readily deprotonated at the methine group by BuLi. Subsequent reactions with alkyl halides, aldehydes, ketones, and imines yield the corresponding substituted derivatives that undergo hydrolysis under acidic conditions to afford the expected functionalized ketones 13, 15,17, 19, 21, 24, and25. Two successive lithiations of (benzotriazolyl)phenoxymethane, each followed by reaction with a trialkylsilyl chloride, alkyl halide, aldehyde, or ketone, generate similar intermediates 27, 29, 31,33, and 36. Subsequent hydrolyses of 27, 29, 31, 33, and 36 yield the functionalized ketones 28, 30, and 32 and the alkanoylsilanes 34 and 37 in good yields.     

A novel solvolytic rearrangement of 2,2-dimethyl-5-(1-Bromomethylethylidene)-1, 3-dioxane-4,6-dione

Treatment of the title compound under basic aqueous conditions leads to 2,2-dimethyl-5-(2-ketopropyl)-1,3-dioxane-4,6-dione; the structure and mechanism of formation of this compound is described.     

Syntheses of Heterocycles from the Sodium Salts of 3-(1-Adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-Adamantyl)-1-hydroxy-1-buten-3-one

The interaction of the sodium salts of 3-(1-adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-adamantyl)-1-hydroxy-1-buten-3-one with hydroxylamine, hydrazine, and guanidine leads to the synthesis of 5-(1-adamantyl)-5-hydroxy- and 5-(1-adamantylmethyl)-5-hydroxy-2-isoxazolines, 3-(1-adamantyl)- and 3-(1-adamantylmethyl)pyrazoles, 3-(1-adamantyl)-2-phenylpyrazole, and 4-(1-adamantyl)-2-amino- and 4-(1-adamantylmethyl)-2-aminopyrimidines.