20800-41-3Relevant academic research and scientific papers
Synthesis and Antimicrobial Activity of Methyl 2-(2-(2-Arylquinazolin-4-yl)sulfanyl)acetylamino Alkanoates
Megahed,Fathalla
, p. 2809 - 2816 (2018/11/10)
A series of methyl 2-(2-(2-arylquinazolin-4-yl)sulfanyl)acetylamino alkanoates have been developed on the basis of the S-chemoselective reaction of 2-arylquinazolin-4(3H)-thione with ethyl chloroacetate and N,N′-dicyclohexylcarbodiimide coupling method with amino acid ester hydrochloride. The precursor 2-arylquinazolin-4(3H)-thione was prepared by a new thiation method from 2-arylquinazolin-4(3H)-one by a two-step reaction that includes chlorination and then the reaction with N-cyclohexyldithiocarbamate cyclohexyl ammonium salt. The antimicrobial activity of the synthesized compounds was tested in vitro via paper-disc agar-plate method against two bacterial strains Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli and a pathogenic yeast Candida albicans. Most synthesized compounds showed remarkable antibacterial activity against E.?coli overpassing the standard reference antibiotics applied: tetracycline, erythromycin, and novobiocin. On the other hand, most synthesized compounds gave moderate antifungal activity against pathogenic yeast C.?albicans.
A novel method for heterocyclic amide-thioamide transformations
Fathalla, Walid,Ali, Ibrahim A. I.,Pazdera, Pavel
supporting information, p. 174 - 181 (2017/02/15)
In this paper, we introduce a novel and convenient method for the transformation of heterocyclic amides into heteocyclic thioamides. A two-step approach was applied for this transformation: Firstly, we applied a chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heated in chloroform for 12 h at 61°C to afford heteocyclic thioamides in excellent yields.
Synthesis and anticonvulsant activity evaluation of 5-Phenyl-[1,2,4] triazolo[4,3-c]quinazolin-3-amines
Zheng, Yan,Bian, Ming,Deng, Xian-Qing,Wang, Shi-Ben,Quan, Zhe-Shan
, p. 119 - 126 (2013/03/29)
In the present study we describe the syntheses and anticonvulsant activity evaluation of 5-phenyl-[1,2,4]triazolo[4,3-c]quinazolin-3-amine derivatives. Their anticonvulsant activity and neurotoxicity were evaluated by the maximal electroshock seizure test (MES) and the rotarod test, respectively. The majority of the compounds prepared were effective in the MES screens at a dose level of 100 mg/kg. Of these compounds, the most promising was compound 8h, which showed an ED50 value of 27.4 mg/kg and a protective index (PI) value of 5.8. These values were superior to those provided by valproate (ED50 and PI values of 272 and 1.6, respectively) in the MES test in mice. As well as its anti-MES efficacy, the potencies of compound 8h against seizures induced by pentylenetetrazole and thiosemicarbazide were also established, with the results suggesting that the GABAergic system-mediated mechanisms might be involved in its anticonvulsant activity. Copyright
Kinetics and mechanism of the base-catalysed cyclisation of 2-(substituted benzoylamino)benzamides giving quinazolin-4-one and quinazolin-4-thione derivatives
Hanusek, Jiri,Sedlak, Milos,Simunek, Petr,Sterba, Vojeslav
, p. 1855 - 1863 (2007/10/03)
Acylation of 2-aminobenzamide and 2-(methylamino)benzamide with substituted benzoyl chlorides in acetone has been used to prepare the respective 2-(substituted benzoylamino)benzamides 1a-i, which were then subjected to sodium methoxide catalysed ring closure to give the respective 2-(substituted phenyl)quinazolin-4 -ones 2a-i. The kinetics of the cyclisation reactions were monitored by UV/Vis spectroscopy at 25 °C in methanolic solutions of sodium methoxide. In the case of 2-(substituted benzoylamino)benzamides 1a-i and 2-(substituted benzoylamino)thiobenzamides 3a-j, non-linear dependences of observed rate constants κobs on the sodium methoxide concentrations were obtained, the shape of them being typical of a reaction with rapid pre- equilibrium. All the cyclisation reactions satisfactorily obeyed the Hammett correlation. In the case of 2 - [(benzoyl) (methyl) amino] benzamides 1e-i, increasing sodium methoxide concentration resulted in a progressive increase in κobs values which is probably due to formation of dianion. In the case of 2-(substituted benzoylamino)thiobenzamides 3b and 3h, which differ in the presence of a methyl group on the nitrogen atom the values of the activation Gibbs energy ΔG? 25 °C, activation enthalpy ΔH? 25 °C, and activation entropy ΔS? 25 °C for their respective cyclisations to 2-(substituted phenyl)quinazoline-4-thiones 4b and 4h were determined. Whereas the ΔG? 25 °C values were very close for the two substances, the ΔH? 25 °C and ΔS? 25 °C distinctly differed. This was interpreted by the enthalpy and entropy factors operating against each other in the cyclisation. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
Synthesis of substituted 2-benzoylaminothiobenzamides and their ring closure to substituted 2-phenylquinazoline-4-thiones
Hanusek, Jiri,Hejtmankova, Ludmila,Kubicova, Lenka,Sedlak, Milos
, p. 323 - 337 (2007/10/03)
Acylation of 2-aminothiobenzamide or 2-methylaminothiobenzamide with substituted benzoyl chlorides has been used to synthesise the corresponding 2-benzoyl-aminothiobenzamides whose subsequent sodium methoxide-catalysed ring closure gives the corresponding quinazoline-4-thiones. These compounds were characterised by means of their 1H- and 13C-NMR spectra. The preferred tautomeric form of selected compounds has been discussed on the basis of their 13C-NMR, IR and Raman spectra. It has been found that in the given medium 1-methyl-quinazoline-4-thiones undergo a replacement of the sulphur substituent by oxygen giving 1-methyl-quinazoline-4-ones. In strong acid media, 2-benzoylaminothiobenzamide is cyclised through its sulphur atom to give 2-phenylbenzo[d-1,3]thiazin-4-one.
