Synthesis of 1-aryl-5-arylazo-3-phenylsulfonylpyrazol-4-ols from 1-bromo-3-phenylsulfonyl-2-propanone

Treatment of 1-bromo-3-phenylsulfonyl-2-propanone ( 1 ) with arenediazonium chloride gave 1-aryl-5-arylazo-3-phenylsulfonylpyrazol-4-ols 5a-h in 13–48% yields.     

Synthesis of 1-aryl-5-chloro-3-(phenylsulfonyl)pyrazol-4-ols from 1,1-dichloro-3-phenylsulfonyl-2-propanone

1,1-Dichloro-3-phenylsulfonyl-2-propanone was treated with arenediazonium chlorides to give 1-arylhydrazono-3,3-dichloro-1-phenylsulfonyl-2-propanones, which were cyclized to 1-aryl-5-chloro-3-(phenylsulfonyl)pyrazol-4-ols on treatmemt with base.     

Synthesis of anti-2-aryl-4-en-1-ols from the corresponding syn isomers

Russian Journal of Organic Chemistry - Stereoselective synthesis of anti-2-aryl-4-en-1-ols from the corresponding syn isomers was accomplished with 71–83% yields via the Mitsunobu reaction.     

A green synthesis of new 3-aryl-4-phenylsulfonyl-5-aminoisoxazoles

The present work describes a new protocol for the synthesis of 5-aminoisoxazoles using α-chlorooximes and 2-phenylsulfonyl acetonitrile via green chemistry routes. The titled 5-aminoisoxazoles 3 were further reacted with 4-nitrobenzoyl chloride to obtain 5-amidoisoxazoles with moderate yields. These heterocyclic compounds were tested in vitro MTT study to investigate inhibitive abilities to some cancer cell lines (C3a, L929, T98g and Mcf-7) and compounds 3a, 3c, 3e and 3h showed noticeable cytotoxic property against four cancer cell lines.     

Transformation of trans-4-aryl-3-chloro-1-(2-chloroethyl)azetidin-2-ones into 3-aryl-2-(ethylamino)propan-1-ols via intermediate 1-(1-aryl-2-chloro-3-hydroxypropyl)aziridines and trans-2-aryl-3-(hydroxymethyl)aziridines

trans-4-Aryl-3-chloro-1-(2-chloroethyl)azetidin-2-ones, prepared through cyclocondensation of chloroketene and the appropriate imines in a diastereoselective way, were unexpectedly transformed into 3-aryl-2-(ethylamino)propan-1-ols using LiAlH(4) in THF under reflux. A stepwise analysis showed that the initially formed 1-(1-aryl-2-chloro-3-hydroxypropyl)aziridines were converted into trans-2-aryl-3-(hydroxymethyl)aziridines, most probably via N-spiro bis-aziridinium intermediates, which were subsequently prone to undergo ring opening by LiAlH(4) to afford 3-aryl-2-(ethylamino)propan-1-ols.     

Polyfunctional imidazoles: VI. Synthesis of 2-amino-1-aryl-4-chloro-1H-imidazole-5-carboxylic acids derivatives

Aryl-2,4-dichloro-5-formylimidazoles by a successive treatment with hydroxylamine and thionyl chloride were converted into 1-aryl-2,4-dichloroimidazole-5-carbonitriles which by the action of sodium azide and tin(II) chloride were transformed into 2-amino-1-aryl-4-chloroimidazole-5-carbonitriles. The consecutive reactions of 2-azido-1-aryl-4-chloro-5-formylimidazoles with N-bromosuccinimide, methanol, or amides led to the formation of methyl esters and amides of 2-azido-1-aryl-4-chloroimidazole-5-carboxylic acids. The reduction of the latter with tin(II) chloride resulted in the corresponding derivatives of 2-amino-1-aryl-4-chloroimidazole-5-carboxylic acids, and the reduction of 2-azido-1-aryl-4-chloroimidazole-5-carboxylic acids was accompanied with decarboxylation and yielded 2-amino-1-aryl-4-chloroimidazoles.     

Synthesis of 1-Aminocarbonylmethyl-5-aryl-4-aroyl-3-hydroxy-3-pyrroline-2-ones

Russian Journal of General Chemistry - A series of new 1-aminocarbonylmethyl-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones has been synthesized through a three-component reaction of aroylpyruvic acid...     

Synthesis of 5-arylazo-2-thiohydantoins

The methylene group of 2-thiohydantoin reacts with diazonium salts to give azothiohydantoins, whose longwave absorption maximum is shifted hypsochromically as compared with the corresponding azorhodanines, and bathchromically compared with azohydantoins.Introduction of an acetyl group, particularly of benzoyl, at position 1 in the hydantoin ring causes considerable bathochromic displacement of the absorption maximum, while introducing a phenylsulfonyl group leaves the absorption maximum unaffected.     

Synthesis of 5-arylazo-2-thiohydantoins

The methylene group of 2-thiohydantoin reacts with diazonium salts to give azothiohydantoins, whose longwave absorption maximum is shifted hypsochromically as compared with the corresponding azorhodanines, and bathchromically compared with azohydantoins. Introduction of an acetyl group, particularly of benzoyl, at position 1 in the hydantoin ring causes considerable bathochromic displacement of the absorption maximum, while introducing a phenylsulfonyl group leaves the absorption maximum unaffected.     

Synthesis and reactions of 4-isopropylidene-1-aryl-3-methyl-2-pyrazolin-5-ones

The reactions of 4-isopropylidene-1-aryl-3-methyl-2-pyrazolin-5-ones 4a-d were investigated under a variety of conditions. In the presence of thiols or piperidine, 4a-d failed to yield conjugate addition products, presumably due to the steric bulk provided by the two methyl substituents of the isopropylidene side chain. Reaction of 4a-d with hydrazine derivatives gave the 1-aryl-3-methyl-2-pyrazolin-5-ones 3a-d and isopropyl-hydrazones. Treatment of 4a with potassium cyanide yielded a stable conjugate addition product which exists as a mixture of tautomers in different solvents. Also, oxidation of 4a with hydrogen peroxide gave a spiroepoxide 22 , while m-chloroperbenzoic acid oxidation afforded both the spiroepoxide 22 , and a small quantity of a hydroxyspiroepoxide 23.     

Reactions of nucleophilic substitution of 4-aryl-5-carbomethoxy-6-methyl-2-chloro-3-cyanopyridines

Methods of synthesis of 5-carbomethoxy-substituted pyrazolo[3,4-b]pyridines and 3H-imidazo[4,5-b]pyridines by their reaction with hydrazine hydrate or as a result of Hofmann rearrangement of the corresponding 2-aminopyridines were developed based on 4-aryl-3-carbamoyl(or cyano)-5-carbomethoxy-6-methyl-2-chloropyridines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.12, pp. 1646–1650, December 1992.     

Practical ways from aldehydes to 2-chloro-1,1,1-trifluoro-2-alkenes and 2-chloro-1,1-difluoro-1-alken-3-ols

A reagent system CF₃CCl₃/Zn(>2 mol)/Ac₂O transformed aldehydes to 2-chloro-1,1,1-trifluoro-2-alkenes exclusively, whereas CF₃CCl₃/Zn(>2 mol)/AlCl₃(cat.) converted aldehydes into 2-chloro-1,1-difluoro-1-alken-3-ols.     

Synthesis of 3-aryl-5-dichloromethyl-1H-pyrazole-1-carboxamides from 1-aryl-3,4,4-trichlorobut-3-en-1-ones

The reaction of 1-aryl-3,4,4-trichlorobut-3-en-1-ones with semicarbazide hydrochloride in the presence of sodium acetate is accompanied by prototropic allylic rearrangement, leading to the formation of two isomeric products, semicarbazones of the initial ketones and 1-aryl-3,4,4-trichlorobut-2-en-1-one semicarbazones. The latter undergo heterocyclization in the presence of triethylamine to give the corresponding 3-aryl-5-dichloromethyl-1H-pyrazole-1-carboxamides.     

Transformations of 3-aryl-2-chloro-2-imidoylaziridines: novel entries to 4-chloro-2,5-diaryl-1H-imidazoles and 2-chloro-2-acylaziridines

The reactivity of stereochemically defined 3-aryl-2-chloro-2-imidoylaziridines, an unexplored class of substituted aziridines, was investigated under various reaction conditions. 2-Chloro-2-imidoylaziridines underwent a novel thermal rearrangement by reflux in acetonitrile via C-C bond cleavage to 4-chloro-2,5-diarylimidazoles in high yield. Alternatively, a novel efficient entry toward 2-aroyl-2-chloroaziridines was based on the chemoselective hydrolysis of 2-chloro-2-imidoylaziridines with hydrochloric acid in aqueous tetrahydrofuran.     

2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性

咪唑啉酮衍生物;反应;2-烷基氨基-3-芳基-5-苄基-1-咪唑啉-4-酮的合成及杀菌活性     

Synthesis of 2-aryl-4-phenyl-5-trifluoromethylimidazoles

Several 2-aryl-4-phenyl-5-trifluoromethylimidazoles have been made from the previously unknown 1-phenyl-3,3,3-trifluoro-1,2-propanedione monohdyrate. One analog, 4-phenyl-2,5-bis(trifluoromethyl)imidazole, is quite acidic, exhibiting pK_a 8.1.     

Synthesis and mass spectral studies of 1-[5-chloro-1-substituted-2(1H)-pyrazin-2-on-3-yl]-5-aryl-3-methylpyrazoles

Sixteen new 1-[5-chloro-1-substituted-2(1H)-pyrazin-2-on-3-yl]-5-aryl-3-methylpyrazoles V have been synthesized by condensation of 5-chloro-1-substituted-3-hydrazino-2(1H)-pyrazin-2-ones III and 1-aryl-1,3-butanediones IV in dry 1,4-dioxane. The general mass spectral fragmentation mode of these compounds has been studied.     

Synthesis and mass-spectrometric study of 2-amino- and 2-chloro-5-aryl-1,3,4-thiadiazoles

The cyclization of aldehyde thiosemicarbazones with ferric chloride yielded 2-amino-5-aryl-1,3,4-thiadiazoles, forming 2-chloro-5-aryl-1,3,4-thiadiazoles in the Sandmeyer reaction. The mass-spectrometric behavior of the 2-amino- and 2-chloro-5-aryl-1,3,4-thiadiazoles was studied; the typical routes of fragmentation characteristic of each group of compounds were found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1416–1419, October, 1986.