SYNTHESIS AND REACTIONS OF SOME NEW HETEROCYCLIC COMPOUNDS CONTAINING THE THIENYLTHIENO[2,3-B]PYRIDINE MOIETY

(4-Aryl-3-cyano-6-(2-thienyl)pyridin-2-ylthio)acethydrazides (5a–c), 3-amino-4-aryl-6-(2-thienyl)thieno[2,3-b]pyridine-2-carbohydrazides (6a–c) and 3-amino-4-phenyl-6-(2-thienyl)thieno[2,3-b]pyridine-2-carboxylic acid (30) were prepared and employed as key intermediates in the synthesis of the title compounds.     

微波辐射一步法合成吡喃和吡喃[2, 3-c]吡唑衍生物

芳醛、丙二腈与5,5-二甲基-1,3-环己二酮或3-甲基-1-苯基-2-吡唑啉-5-酮在乙醇溶剂中用哌啶作催化剂,经微波辐射一步合成了2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-5,6,7,8-四氢苯并吡喃和6-氨基-5-氰基-4-芳基-1,4-二氢吡喃[2,3-c]吡唑,反应在2～12min内完成,产率53%～91%。     

Studies on Condensed Heterocyclic Compounds XVII. Synthesis of 6-(1-Aryl-5-methyl-1,2,3-triazol-4-yl)-3-phenyl-s-triazolo[3,4-b]-1,3,4-thiadiazoles

Treatment of 4-amino-5-mercapto-3-phenyl-1,2,4-triazole 2 with 1-aryl-4-carboxy-5-methyl-1,2,3-triazoles 1a-1j in a one-step reaction yielded several 6-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-3-phenyl-s-triazolo[3,4-b]-1,3,4-thiadiazoles 3a-3j . The structures of all the products were established on the basis of elemental analyses and spectral data. The fragmentation of the mass spectra of 3a-3j under electron impact was discussed.     

Synthesis of heterocycles. Part VI. Synthesis and antimicrobial activity of some 4-amino-5-aryl-1,2,4-triazole-3-thiones and their derivatives

4-Amino-5-aryi-1,2,4-triazole-3-thiones I react with acid chlorides to yield 4-acylamino-5-aryl-1,2,4-triazole-3-thiones II. Compounds I also react with methylene iodide, chloroacetonitrile and methyl bromoacetate to give bis-(4-amino-5-aryl-1,2,4-triazol-3-ylthio)methanes III, 4-amino-5-aryl-3-cyanomethylthio-1,2,4-triazoles IV and 4-amino-5-aryl-3-carbomethoxymethylthio-1,2,4-triazoles V, respectively. Compounds V react with hydrazine hydrate to give the corresponding acid hydrazides VI which in turn condenses with acid chlorides and aldehydes to afford respectively 1-[(4-amino-5-aryl-1,2,4-triazol-3-ylthio)acetyl]-2-aroylhydrazines VII and aryl methylene (4-amino-5-aryl-1,2,4-triazol-3-ylthio)acethydrazones VIII. The antimicrobial activities of the above compounds were screened against different strains of bacteria and fungi.     

Interactions of lysozyme with 6-amino-4-aryl-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitriles: a fluorescence quenching study.

The interactions between 6-amino-4-aryl-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile and lysozyme (LYSO) were investigated by using tryptophane fluorescence quenching and 6-amino-4-(2-hydroxyphenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonitrile (1) was studied in detail because of its high water solubility. At different temperatures, the quenching constants K(SV), the binding constants K and the binding sites n of LYSO with 1 were determined and the thermodynamic parameters were calculated. The distance r between tryptophane residues and 1 was obtained according to the Forster mechanism of non-radiation energy transfer. Furthermore, synchronous fluorescence spectroscopy data indicated that the association between 1 and LYSO changed LYSO's conformation and that the hydrophobic interaction played a major role in 1-LYSO association. It was proved that the fluorescence quenching of LYSO by 1 was related to the formation of a 1-LYSO complex and to a non-radiation energy transfer.     

Synthesis of new bis-1,2,4-triazole derivatives

A series of new 1,2/1,3-bis[o-(N-methylidenamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives 4 were prepared in good yields by treatment of 4-amino-3-aryl-5-phenyl-4H-1,2,4-triazoles 2 with certain bis-aldehydes 1.Compounds 4 were reduced with NaBH(4) to afford the corresponding 1,2/1,3-bis[o-(N-methylamino-3-aryl-5-phenyl-4H-1,2,4-triazole-4-yl)phenoxy]ethane/propane derivatives 5. All new compounds were characterized by IR, (1)H-NMR, (13)C-NMR and mass spectral data.     

Reactions of 1-aryl-2-bromo-3,4,4-trichlorobut-3-en-1-ones with some nucleophilic reagents

Reactions of 2-bromo-1-phenyl- and 2-bromo-1-(4-methylphenyl)-3,4,4-trichlorobut-3-en-1-ones with morpholine and diethylamine are accompanied by prototropic allylic rearrangement, leading to 3-amino-1-aryl-2-bromo-4,4-dichlorobut-2-en-1-ones as mixtures of E and Z isomers. The title compounds react with hydrazine, hydroxylamine, and thiourea to give the corresponding 5-aroyl-4-methoxypyrazoles, 3-aryl-5-hydroxyiminomethyl-4-methoxyisoxazoles, and 2-amino-4-aryl-5-trichlorovinylthiazoles.     

1,5-Electrocyclization of 1-alkyl- 3-[(2Z)-2,4-diaryl-4-oxobut-2-en-1-yl]-1H-benzimidazol-3-ium bromides

Cyclization of 1-alkyl-3-[(2Z)-2,4-diaryl-4-oxobut-2-en-1-yl]-1H-benzimidazol-3-ium bromides occurs in the presence of MeONa at a reduced temperature of 5–10°C via a 1,5-electrocyclization mechanism to give 3a,4-dihydro-3H-pyrrolo[1,2-a]benzimidazoles. These are unstable under the reaction conditions and are readily converted to {1-[2-(alkylamino)phenyl]-4-phenyl-1H-pyrrol-3-yl}(phenyl)methanones.     

An aqueous,catalyst-free and three-component synthesis of 6-amino-3-(trifluoromethyl)-1,4-dihydro-1-phenyl-4-arylpyrano[2,3-c]pyrazole-5-carbonitriles

A concise synthesis of 6-amino-4-aryl-3-(trifluoromethyl)-1,4-dihydro-1-phenylpyrano[2,3-c]pyrazole-5-carbonitriles was performed effectively in aqueous media without catalyst by the reaction of aryl aldehydes, malononitrile, and 1-phenyl-3-(trifluoromethyl)-1H-pyrazol-5(4H)-one. This method has the advantages of mild condition, avoidance of the use of catalysts, high yields, and environmentally benign procedure.     

Synthesis of 1H-thieno[3,4-c]pyrazoles,thieno[3,4-b]furans,selenolo[3,4-b]furans and pyrrolo[3,4-d]thiazoles

Starting from the readily available aryl 2-methyl-5-phenyl-3-furyl ketones, 5-methyl-1H-1-phenylpyrazole-4-yl ketones and 4-methyl-2-phenyl-5-thiazolylcarboxaldehyde, a series of 2-phenyl-4-arylthieno[3,4-b]-furan, 2-phenyl-4-(p-methoxyphenyl)selenolo[3,4-b]furan, 4-aryl-1H-1-phenylthieno[3,4-c]pyrazole and 5-benzyl-2-phenylpyrrolo[3,4-d]thiazole were prepared in high yield.     

Reactions of 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones with arylamines and hydrazine hydrate

Depending on the reaction condition, 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones reacted with aromatic amines to yield 3-arylamino-3-pyrrolin-2-ones or 4-[aryl (arylamino) methylene]tetrahydropyrrole-2,3-diones. Reactions of 1-(4-aminosulfonylphenyl)-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones with hydrazine hydrate afforded pyrrolo[3,4-c]pyrazol-6-ones.     

Solvent-free microwave assisted synthesis of substituted (E)-phenyl{3-(2-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]vinyl)benzofuran-2-yl}methanones and their antimicrobial activity

Russian Journal of General Chemistry - New substituted (E)-phenyl{3-(2-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]vinyl)benzofuran-2-yl}methanones have been synthesized from substituted...     

Synthesis of 5-aryl-3-carbazoyl-1,3,4-oxadiazol-2(3H)-one. Derivatives and their ring transformation into 5-benzamido-1,2,4-triazolidine-3,5-dione derivatives

Some 5-aryl-3-carbazoyl-1,3,4-oxadiazol-2(3H)-one derivatives 6 and 9 have been synthesized in two ways. The expected thermal ring transformation into 2,5-disubstituted 1,3,4-oxadiazoles did not occur but, by acid hydrolysis of 5-aryl-3-[3-benzylidene-2-methyl(or phenyl)carbazoyl]-1,3,4-oxadiazol-2(3H)-ones 6 , a new ring transformation took place and the corresponding 4-benzamido-1-methyl(or phenyl)-1,2,4-triazolidine-3,5-dione derivatives 11 were formed. The 4-amino-1-phenyl-1,2,4-triazolidine-3,5-dione ( 19 ) has been prepared and its structure was confirmed by some reactions.     

Reactions of 2-amino-, 2-alkylamino-, and 2-piperidino-1-azaazulenes with aryl and chlorosulfonyl isocyanates

Reaction of 2-amino-1-azaazulene with phenyl isocyanate gave 3-phenyl-2H-3,4-dihydro-1,3,4a-triazabenz[5,4-a]azulene-2,4-dione. Reactions of 2-alkylamino-1-azaazulenes with aryl isocyanates gave 2-(N-ethyl-N′-arylureido)-1-azaazulenes initially, which rearranged to N-aryl-2-alkylamino-1-azaazulene-3-carboxamides and successive reaction with another molar amount of aryl isocyanate furnished uracil-fuzed 1-azaazulenes. Reaction of 2-piperidino-1-azaazulene with aryl isocyanate gave N-aryl-2-piperidino-1-azaazulene-3-carboxamide. Reaction of 2-(substituted amino)-1-azaazulenes with chlorosulfonyl isocyanate gave 3-cyano- and 3-chloro-2-(substituted amino)-1-azaazulenes.     

Synthesis and reactions of 3-(3-ethoxycarbonyl-1-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-4-yl)propenic acid

The reaction of ethyl 4-formyl-1-phenyl-1H-pyrazole-3-carboxylate with the malonic acid led to the formation (2E)-3-(3-ethoxycarbonyl-1-phenyl-1H-pyrazol-4-yl)propenic acid. In reactions of this acid chloride with 4-amino-5-aryl(hetaryl)-4H-1,2,4-triazole-3-thiols were obtained ethyl 4-[(E)-2-{3-aryl(hetaryl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-6-yl}ethenyl]-1-phenyl-1H-pyrazoe-3-carboxylates, with 5-aryltetrazoles, ethyl 4-[(E)-2-(5-aryl-1,3,4-oxadiazol-2-yl)-ethenyl]-1-phenyl-1H-pyrazole-3-carboxylates, with 1-(2-hydroxy-3,5-dimethylphenyl) followed by the Baker-Venkataraman rearrangement and the cyclization, ethyl 4-[(E)-2-(6,8-dimethyl-4-oxo-4Hchromen-2-yl)ethenyl]-1-phenyl-1H-pyrazole-3-carboxylate.     

Reactions of 2-benzylidenemalononitrile and 2-nitro-3-phenylacrylonitrile with aryl azides

Reactions of 2-benzylidenemalononitrile and 2-nitro-3-phenylacrylonitrile with aryl azides in diethyl ether at room temperature gave mixtures of regioisomeric 1(3)-aryl-5-phenyl-4,5-dihydro-1(3)H-1,2,3-triazole-4,4-dicarbonitriles and 1-aryl-5(4)-phenyl-1H-1,2,3-triazole-5(4)-carbonitriles, respectively. 2-Benzylidenemalononitrile reacted with the same arylazides on heating in boiling chloroform to produce 1-aryl-2-phenylaziridine-2,2-dicarbonitriles.     

A strategy for the synthesis of 2-aryl-3-dimethylaminopyrazolo-[3,4-c]pyridines that utilizes [4+1] cycloaddition reactions of 5-arylazo-2,3,6-trisubstituted pyridines

In order to explore the viability and generality of a recently uncovered [4+1] cycloaddition based strategy for the preparation of pyrazolo[3,4-c]pyridine derivatives, members of a series of 5-arylazo-2,3,6-trisubstituted pyridines were prepared by reactions of 3-oxo-2-arylhydrazonopropanals with 3-oxo-3-phenylpropionitrile. The results show that 3-oxo-3-phenylpropionitrile reacts with hydrazone substrates, which do not contain electron-withdrawing substituents on the N-aryl ring of the arylhydrazone moieties, to efficiently produce 6-aryl-2-phenyl-5-arylazonicotinonitriles. In contrast, 2-amino-6-aryl-5-arylazo-3-benzoylpyridines are generated in reactions of 3-oxo-2-arylhydrazonopropanals, which contain electron-withdrawing substituents on the N-aryl moiety. In the forecasted manner, the 6-aryl-2-phenyl-5-arylazonicotinonitriles undergo smooth reactions with dimethylformamide dimethylacetal (DMF-DMA) that led to formation of a new class of 2-aryl-3-dimethylaminopyrazolo[3,4-c]pyridines. The mechanism for this process involves a [4+1] cycloaddition reaction that takes place through initial nucleophilic addition of dimethylamino)methoxycarbene, generated from DMF-DMA, to the azadiene moiety of the arylazopyridines followed by cyclization of the formed zwitterionic intermediate.     

Five-membered 2,3-dioxo heterocycles: XCIII. Spiro heterocyclization of 4,5-diaroyl-1H-pyrrole-2,3-diones with acyclic enamine. Crystalline and molecular structure of substituted 1,7-diazaspiro[4.4]nonane

4,5-Diaroyl-1-aryl-1H-pyrrole-2,3-diones reacted with ethyl 3-amino-3-phenylprop-2-enoate to give ethyl 4-aroyl-1,6-diaryl-3-hydroxy-2-oxo-8-phenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylates. The crystalline and molecular structures of ethyl 4-benzoyl-3-hydroxy-1-(4-methylphenyl)-2-oxo-6,8-diphenyl-1,7-diazaspiro[4.4]nona-3,6,8-triene-9-carboxylate were determined by X-ray analysis.     

Two-pot synthesis of N,N-disubstituted 4H-3,1-benzothiazin-2-amines from aryl(2-isothiocyanatophenyl)methanones and secondary amines

A convenient synthesis of N,N-disubstituted 4H-3,1-benzothiazin-2-amines from aryl(2-isothiocyanatophenyl)methanones using a two-pot procedure has been developed. Thus, treatment of these isothiocyanato ketones with secondary amines gave the corresponding keto thioureas, which were allowed to react with sodium borohydride or methylmagnesium bromide to afford 1,1-dialkyl-3-{2-[aryl(hydroxy)methyl]phenyl}thioureas or 1,1-dialkyl-3-[2-(1-aryl-1-hydroxyethyl)phenyl]thioureas, respectively, in one pot. Hydrobromic acid-mediated cyclization of these hydroxy thiourea precursors provided the desired 4H-3,1-benzothiazin-2-amines.     

Reaction of 4-thioxo-1,3-benzothiazines with thiocarbohydrazine: Synthesis and reactivity of 1,3,4-triazolo[3,2-c]quinazoline derivatives

2-Aryl-4-thioxo-1,3-benzothiazines react with thiocarbohydrazide to give the new mesoionic compounds an-hydro 1-amino-5-aryl-2-mercapto-1,3,4-triazolo[3,2-c]quinazolin-4-ium hydroxides. These compounds react with methyl iodide, aldehydes and phenacyl bromides to give 1-amino-5-aryl-2-methylthio-1,3,4-triazolo-[3,2-c]quinazolin-4-ium iodides, 4-arylidenamino-3-(o-aroylamino)phenyl-1H-1,2,4-triazolin-5-thiones and 3-(o-aroylamino)phenyl-6-aryl-7H-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines, respectively. These latter compounds by sequential treatment with methyl trifluoromethanesulphonate and triethylamine lead to 3-(o-aroylamino)-phenyl-6-aryl-1-methyl-7-mercapto-1H-pyrazolo[5,1-c]-1,2,4-triazoles.