scholarly journals Synthesis of various fused pyrimidine rings with their pharmacological and antimicrobial evaluation

2014 ◽  
Vol 79 (9) ◽  
pp. 1059-1073 ◽  
Author(s):  
Salem Mounir ◽  
Magda Marzouk ◽  
Naglaa Mahmoud

Various fused pyrimidine such as furo[2,3-d]pyrimidine, triazolo[1,5-a]pyrimidine, tetrazolo[1,5-a]pyrimidine were synthesized from the reactions of thioxopyrimidine-6(1H)-ones with ethyl chloroacetate (under different reaction conditions), thiourea, and sodium nitrite. Pyrimidine thiones reacted with POCl3/PCl5 to give the chloro derivatives which reacted with sodium azide, and thiourea to give the tetrazolo[1,5-c]pyrimidine, pyrimido pyrimidine. Thioxopyrimidine-6(1H)-ones reacted with benzyl amine to give pyrrolo[2,3-d]pyrimidinethione. Theoretical calculation using MIDO/3, Fukui indices and the heat of formation of some compounds were carried out. The pharmacological and antimicrobial activities of some of the synthesized products were also evaluated.

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Periyan Durairaju ◽  
Chinnasamy Umarani ◽  
Govindasami Periyasami ◽  
Perumberkandigai Adikesavan Vivekanand ◽  
Mostafizur Rahaman

Herein we report new multiblock chalcone conjugate phthalimide and naphthalimide functionalized copolymers with a topologically novel architecture synthesis using nucleophilic substitution and polycondensation methodology. The structures of the synthesized novolacs were elucidated on the basis of their spectroscopic analysis including FTIR, 1H NMR, and 13C NMR spectroscopy. Further, the number-average and weight-average molecular weights of the novolac polymers were determined by gel permeation chromatography (GPC). We examined the solubility of the synthesized polymers in various organic solvents including CHCl3, CH3CN, THF, H2O, CH3OH, DMSO, and DMF and found they are insoluble in both methanol and water. The novolac polymers were evaluated for their photophysical properties and microbial activities. The investigation of the antimicrobial activities of these polymers reveals significant antimicrobial activity against the pathogens E. coli, S. aureus, C. albicans, and A. niger.


2019 ◽  
Vol 31 (12) ◽  
pp. 2740-2744
Author(s):  
Anil Verma ◽  
Vinod Kumar ◽  
Ramesh Kataria ◽  
Joginder Singh

Eleven acetohydrazide linked pyrazole derivatives were designed and synthesized via condensation of acetohyadrazide with different substituted formyl pyrazole derivatives under mild reaction conditions. Synthesized compounds were characterized on the basis of IR, NMR (1H & 13C) and mass spectrometry. The antimicrobial activities of all the compounds were screened against four bacterial and two fungal strains. Among the synthesized compounds, three compounds viz. 6b, 6c and 6d were found as efficient antimicrobial agents in reference to the standard drugs viz. ciprofloxacin and amphotericin-B. Further, structure-activity relationship (SAR) study revealed that electron-withdrawing group enhances the antimicrobial potential of synthesized derivatives as compared to other groups present in the ring. Hence, among compounds 6b-c, compound 6d could be explored further against other microbes to prove its vitality.


2009 ◽  
Vol 6 (3) ◽  
pp. 866-870
Author(s):  
CH. Sridevi ◽  
K. Balaji ◽  
A. Naidu ◽  
R. Sudhakaran

2,3-Diphenyl quinoxaline(SI)was fused with 2-amino benzothiazoles(SII)by a methylene bridge, which was then allowed for acetylation. The acetylated product (SIV) was made to react with different aromatic aldehydes to give chalcones(SV1-SV5). Chalcones refluxed with substituted acid hydrazides to afford different phenyl pyrazolo benzothiazolo quinoxaline derivatives(SVI1-SVI15). The structure of chalcones and phenyl pyrazolo benzothiazolo quinoxaline derivatives were confirmed by M.P, TLC and spectral data. All the synthesized compounds were screened for their antimicrobial activities.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shabbir Hussain ◽  
Saqib Ali ◽  
Saira Shahzadi ◽  
Saroj K. Sharma ◽  
Kushal Qanungo ◽  
...  

Organotin (IV) carboxylates with the general formulae R2Sn(Cl)L [R = Me (1),n-Bu (2), Ph (3)] and R3SnL [R = Me (4), Ph (5)] have been synthesized by the reaction of 4-piperidinecarboxylic acid (HL) with KOH and R2SnCl2(R = Me,n-Bu, Ph)/R3SnCl (R = Me, Ph) in methanol under stirring conditions. The metal ligand binding site, structure, and stability of complexes have been verified by FT-IR, (1H,13C) NMR, EI-MS technique, and semiempirical study. The FT-IR data indicate the bidentate chelating mode of the carboxylate ligand which is also confirmed by semiempirical study. In solution state, five and four coordinated geometry around tin was confirmed by NMR spectroscopy. The EI-MS data agreed well with the molecular structure of the complexes. Thermodynamic parameters and molecular descriptors were calculated by using semiempirical PM3 method. HOMO-LUMO calculations show that chlorodiorganotin complexes are more susceptible to nucleophilic attack as compared to triorganotin complexes. Computed negative heat of formation indicates that complexes1–4are thermodynamically stable. The organotin(IV) carboxylates displayed powerful antimicrobial activities against various strains of bacteria and fungi and their minimal inhibitory concentration were also evaluated. The complexes exhibited comparatively higher hemolytic activity as compared to free ligand.


2002 ◽  
Vol 117 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Shigeo Kondo ◽  
Akifumi Takahashi ◽  
Kazuaki Tokuhashi ◽  
Akira Sekiya ◽  
Yasufu Yamada ◽  
...  

2019 ◽  
Vol 4 (4) ◽  
pp. 232-235
Author(s):  
H.M. Naveena Kumari ◽  
Manjunath Harihara Mathada ◽  
Mahesh Kumar ◽  
K.T. Suda ◽  
K.M. Basavaraja

Present work reports the biologically important benzofuran aryl ureas and carbamates. The benzofuran ring was formed by reacting bromo salicylaldehyde with diethyl bromomalonate in presence of dry acetone and anhydrous potassium carbonate to obtain 5-bromo-2-ethyl carboxylate (1). The obtained ester (1) was converted into corresponding hydrazide (2) by treating with hydrazine hydrate in ethanol. Compound 2 was then converted into 5-bromobenzofuran-2-carbonyl azide (3) by treating it with sodium nitrite in dioxane and acetic acid. The compound 3 is converted into 5-bromobenzofuranyl aryl ureas (4a-e) after treating primary amines and anhydrous toluene. 5-Bromobenzofuranyl aryl carbamate (5) and ethyl carbamate (6) were also synthesized by treating compound 3 with substituted phenol in toluene and ethanol respectively. All the compounds were characterized by NMR, IR and screened for antimicrobial activities.


2008 ◽  
Vol 452 (1-3) ◽  
pp. 29-32 ◽  
Author(s):  
Xavier Lories ◽  
Jacques Vandooren ◽  
Daniel Peeters

2000 ◽  
Vol 78 (10) ◽  
pp. 1295-1298 ◽  
Author(s):  
J Peter Guthrie ◽  
Roger T Gallant

Recently we reported a study of the thermodynamics of methanesulfonic acid and some of its derivatives. The foundation of these results was a measurement of the heat of reaction of S-methyl thioacetate with aq sodium hypochlorite, leading to methanesulfonic acid. We have reinvestigated this reaction and discovered that contrary to the initial stoichiometry experiments, the stoichiometry under the reaction conditions is not as was believed and that the heat of reaction observed was spuriously high. We have found a new reaction, that of sulfite ion with methyl methanesulfonate, which does allow a clean determination of the heat of formation of methanesulfonic acid. Revised thermodynamic quantities for methanesulfonic acid, methanesulfonyl chloride, and methyl methanesulfonate are reported here.Key words: sulfonic acid, heat of reaction, free energy of formation, SN2 reaction.


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