Synthesis and characterization of polythiophene derivatives with nitrogen heterocycles on the side chain

The Grignard metathesis reaction of 2,5‐dibromo‐3‐(5′‐hexylpyridine‐2′‐yl)thiophene ( M1 ) with i‐PrMgCl afforded 5‐bromo‐2‐chloromagnesio‐3‐(5′‐hexylpyridine‐2′‐yl)thiophene ( GM1 ) in the 86% selectivity. The Kumada coupling polymerization by Ni(dppp)Cl₂ gave poly M1 having the roughly controlled molecular weight between 6700 and 23,400. The characterization using the gel permeation chromatographic and matrix‐assisted laser desorption/ionization‐time of flight mass spectra indicated the diffusion of the nickel catalyst from the propagating end. Based on the GC and ¹H NMR spectra, the head‐to‐tail content of poly M1 was calculated to be 89%. The regioselective Grignard metathesis reactions of 5,5′‐dibromo‐4‐(5″‐hexylpyridine‐2″‐yl)‐2,2′‐bithiophene ( M2 ) and 5,5′‐dibromo‐4‐(5″‐hexylpyrimidine‐2″‐yl)‐2,2′‐bithiophene ( M3 ) also occurred at the ortho‐position of the nitrogen heterocycle. The Kumada coupling polymerizations gave poly M2 and poly M3 having the head‐to‐tail content of 75% and 85%, respectively. The UV–vis spectra of polymers suggested that the polymer conformation becomes more planar in the order of poly M1 < poly M3 < poly M2 , which was investigated by the theoretical calculation of the model oligomers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2166–2174     

Synthesis,characterization, and antimicrobial evaluation of some novel anthracene heterocycles derivatives

A series of novel heterocyclic compounds containing anthracene moiety was synthesized. Reaction of (11R,15S)-9,10-dihydro-9,10-[3,4]furanoanthracene-12,14-dione with 2-cyanoacetohydrazide gave 2-cyano-pyrroloanthracen acetamide (1) , which acts as an adaptable material for the synthesis of new heterocyclic compounds. The synthesized compounds were examined for their antimicrobial activity against Escherichia coli and Staphylococcus aureus via p-iodonitrotetrazolium violet formazon assay. The results exhibited great activity against the tested strains with a minimum bactericidal concentration range from 0.636 to 3.8 mg/mL) and 0.159 to 3.6 mg/mL for E coli and S aureus, respectively. Interestingly, the highest activity was recorded for chromene derivative (6) against both strains.     

Synthesis of dimethylamino derivatives of some condensed heterocycles from dimethylphosgeneimmonium chloride

Diazo coupling of indazole-3-diazonium chloride with 1-(2,4-dinitrophenyl)-3,5-bis(dimethylamino)pyrazole, obtained from dimethylphosgeneimmonium chloride, and subsequent cyclization of the azo compound lead to the formation of the dimethylamino derivatives of a new polycyclic system — benzo[h]dipyrazolo[3,2-c:3,4-e]-1,2,4-triazine. Previously unknown 3-dimethylamino derivatives of 1,2,4-triazolo-[3,4-b]benzothiazole were synthesized by reaction of dimethylphosgeneimmonium chloride with 2-hydrazinobenzothiazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 403–406, March, 1978.     

Guanidine derivatives of nitrogen heterocycles

The synthesis of guanidine derivatives of nitrogen heterocycles was accomplished by means of the reactions of heterocyclic amines with S-methylisothiourea sulfate or N,N,S-trimethyl-isothiourea hydriodide. It is shown that the reaction depends on the basicity of the starting amine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 249–251, February, 1971.     

Synthesis and antitumor activity of some nitrogen heterocycles bearing pyrimidine moiety

Synthesis of novel pyrimidine derivatives 4-16 was accomplished by heterocyclization of polarized system, for example, Chalcone. Claisen-Schmidt condensation of 2-acetyl naphthalene with 4-(N, N-dimethylaminobenzaldehyde) afforded chalcone 3 , which was utilized for synthesis various pyrimidine derivatives by treatment with urea, thiourea, and guandine hydrochloride in ethanolic sodium hydroxide solution. The reactivity of the synthesized pyrimidine derivatives towards different nucleophilic and electrophilic reagent were examined. The constructions of the newly synthesized pyrimidine derivatives were elucidated from their spectral and elemental analysis. All the synthesized compounds were tested in vitro for their anticancer activities against HePG-2 and MCF-7 cell lines. Some of them posses a wide range of pharmacological activity. Finally, a molecular docking study was conducted to reveal the probable interaction with the dihydrofolate reductase (DHFR) active site.     

Synthesis of heterocycles from molecular nitrogen as a nitrogen source

Nitrogen fixation is a very attractive process. We succeeded in nitrogen fixation using a TiCl₄‐ or Ti(O‐i‐Pr)₄‐Li‐TMSCl system. Nitrogen fixation proceeds at room temperature under 1 atmosphere pressure of nitrogen to give a mixture of titanium nitride complex 12 , titanium nitrogen complex 13 , and N(TMS)₄. Using the titanium nitrogen complexes 1 , various heterocycles were synthesized from the corresponding ketocarbonyl compounds. Nitrogen in air could be fixed using this method. The total syntheses of lycopodine and monomolin I were achieved from nitrogen in air as the nitrogen source. On the other hand, transmetalation of the nitrogen moiety of titanium nitrogen complexes 1 to a palladium complex was realized, and the non‐substituted anilines could be synthesized from ArX and N₂ in the presence of the palladium catalyst. Furthermore, amide could be synthesized from ArX, CO, and N₂ using the palladium catalyst.     

Synthesis of bioactive nitrogen heterocycles from marine organisms

Recently many bioactive indole alkaloids have been isolated from marine organisms. Many of them have novel ring systems which are not found in the indole alkaloids isolated from higher plants and molds on the land. We have chosen β-carboline alkaloids, eudistomins and manzamines, as targets for total synthesis.     

Synthesis of bridgehead nitrogen heterocycles

Reductive cyclizations of N-[2-(2-pyridyl)ethyl]imides were accomplished by employing a palladium on carbon catalyst in ethanolic acetic acid as the hydrogenation medium. Reduction of the corresponding N-[2-(2-quinolyl)ethyl]imides ceased at the 1,2,3,4-tetrahydroquinolyl stage. Controlled reduction of the tetrahydroquinolyl imides with sodium borohydride gave amido alcohols which afforded bridgehead nitrogen heterocycles upon cyclodehydration.     

Synthesis of alpha-trifluoromethylated nitrogen heterocycles

The syntheses of various alpha-trifluoromethylated nitrogen heterocycles have been achieved from readily available alpha-(trifluoromethyl)homoallylamine through a ring-closing metathesis.     

Synthesis and characterization of some important indazolyl derivatives

A series of some important indazolyl derivatives of pyrazoles, diazepines, thiopyrimidines, thiazines and chromones were synthesized and characterized with the help of spectral data. Some of the synthesized compounds are tested for antimicrobial and antioxidant activities.     

Synthesis and mass spectral fragmentation patterns of some nitrogen heterocycles with antimicrobial activity

5-(P-tolyl)-2-[(3-bromo-4-methoxy benzylidene) hydrazino]-thiazole 3, 3-[(3-bromo-4-mehtoxy benzylidine) amino]-2-thiohydantion 5, and 4,6-disubstituted-3-[(3-bromo-4-methoxybenzyliden) amino]-2-thioxo pyrimidines 10 have been prepared via cyclization of 3-bromo-4-methoxy benzaldehyde thiosemicarbazone 2 with 4-methyl phenacyl bromide, ethyl chloroacetate, and dicarbonyl compounds in different conditions. Acetylation of 3 and 5 with acetic anhydride gave the corresponding monoacetyl derivatives 4 and 6, while the acetylation of 5 with acetic anhydride in the presence of fused sodium acetate gave diacetyl derivative 7. Condensation of compound 5 with benzaldehyde in the presence of piperidine yielded the corresponding 3-substituted-5-benzylindene 2-thiohydation 8. Acetylation of compound 8 with acetic anhydride gave the corresponding 1-acetyl-3-substituted-5-benzylidene-2-thiohydantion 9. The mass spectral fragmentation patterns of some prepared compounds are investigated in order to elucidate the structure of the synthesized nitrogen heterocycles.     

Synthesis and NMR analysis of spiranic heterocycles from carbohydrate derivatives

We report the synthesis of some furanose and pyranose acylhydrazones and their heterocyclization products. The new compounds were characterized physically and spectroscopically and the syn‐anti and (R)‐(S) configuration was determined by NOESY experiments. We discuss the influence of the nucleophile, the temperature and the precursor structure on the heterocyclization products.     

Quaternary salts of some heterocycles containing nitrogen

A series of mono- and biquaternary salts were synthesized from 1, 3-dichloropropane-2-ol and the nitrogen-containing heterocycles quinoline, isoquinoline, quinaldine, pyridine, 2-picoline, and lepidine. The UV-spectra of the compounds obtained were investigated.     

Synthesis and characterization of palladium(II) complexes of some tellurium heterocycles

Summary A series of square planar complexes of the type [PdX₂L₂] where X=Cl, Br, I; L=telluracyclopentane (tcp), telluracyclohexane (tch) or benzotelluracyclopentane (btp) have been synthesised. The complexes were characterised by far-i.r., n.m.r. and u.v.-vis. spectroscopy. The data implytrans-geometries except for the complex [PdCl₂(tch)₂] where a mixture ofcis- andtrans-isomers is obtained.     

Synthesis of some nitrogen heterocycles and in vitro evaluation of their antimicrobial and antitumor activity

Treatment of ethyl β-aryl-α-cyanoacrylate (2a, b) with thiourea, guanidine hydrochloride, and thiosemicarbazide in presence of anhydrous potassium carbonate in methanol led to formation of pyrimidine derivatives 3 and 5 and thiosemicarbazone derivative 9. Thiazole derivative 10 was prepared via cyclization of thiosemicarbazone derivative 9 with 4-methoxy phenacyl bromide. Acetylation of 3a, 5, and 10 with acetic anhydride yielded the acetoxy and N-acetyl derivatives 4, 6, and 11. The mass-spectral fragmentation patterns of nitrogen heterocycles were investigated to elucidate the structure of the prepared compounds. Biological studies of nitrogen heterocycles were carried out to investigate their antimicrobial and anticancer activities; it was found that compounds 5, 10, and 11 were highly active against bacteria and fungi, and compounds 3a and 3b were also active against bacteria and fungi.     

Synthesis and characterization of some chalcones and their cyclohexenone derivatives

A series of chalcones and their derivatives have been synthesized. Chalcones, 1-(1,3-benzodioxol-5-yl)-3-(aryl)-prop-2-en-1-ones were prepared by the aldol condensation of 1-(1,3-benzodioxol-5-yl)ethanones and aryl aldehydes. Based-catalyzed condensation of 1-(1,3-benzodioxol-5-yl)-3-(aryl)prop-2-en-1-ones with ethyl acetoacetate yields corresponding ethyl 4-(1,3-benzodioxol-5-yl)-6-(aryl)-2-oxocyclohex-3-ene-1-carboxylates. Some of the synthesized chalcones were reported in the literature; the newly synthesized compounds were characterized by single crystal X-ray studies, IR, ¹H-NMR and LCMS mass spectral analysis.     

Synthesis of some new mesoionic heterocycles

The synthesis of various substituted 1-hydroxy-2-chloroacetyl-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt, 1-hydroxy-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt, 1-hydroxy-2-piperidinoacetyl-6-thia-10b-aza-2a-azoniaaceanthrylene hydroxide inner salt is described. The ir is also included.     

Synthesis and biological activity of bridgehead nitrogen heterocycles

The reaction of 3-(2,4-dichlorophenyl)-5-mercapto 1,2,4–1H-triazole with α-haloketones and with 1,2-dibromoethane leading to the formation of fused heterocycles were carried out and the orientation of cyclization was studied. The reaction of 3-(2,4-dichlorophenyl)-5-mercapto-4-amino-1,2,4-s-triazole with α-haloketones