Determination and evaluation of acidity constants of some imidazole and thiazole linked acetamide compounds

In this work, the effect of substituents on the acidity constants of some acetamide derivatives was investigated. The acidity constants of nine acetamide derivatives were determined at 25 °C using a UV spectrophotometric method. When the molecules possessed different substituents the values of the acidity constants changed from 6.01 to 8.22 for the first protonation and from 3.07 to 4.73 for the second protonation. The first protonation under these circumstances was observed to occur on the nitrogen atom of the 2-mercaptoimidazole ring. The second protonation was observed to occur on the nitrogen atom of the thiazole ring

Aminotiyazollerin benzimidazol, benzotiyazol, benzofuran ve naftofuran türevlerinden yeni bileşiklerin sentezi ve antimikrobiyal etkilerinin değerlendirilmesi

The thiazole ring is the core of bioactive molecules that generate broad activity. These activities include anticonvulsant, antimicrobial, antituberculosis, antiviral, etc. In this work, starting from seconder/cyclic amines, new compounds containing thiazole and benzimidazole/benzothiazole/benzofurane/naphtofurane rings were synthesized, and their antimicrobial effects were evaluated. 9 compounds were synthesized by converting the seconder and cyclic amines to thiourea, and continued by thiazole ring closure. Ring closure was achieved by methylene-carbonyl condensation except conventional methods. Compound characterization was realized by FT-IR, 1 H NMR and 13C NMR and HRMS. Compounds did not show significant activity on bacterial strains. Nine aminothiazole derivatives have been synthesized successfully. Compounds did not show important antibacterial activity and thus were evaluated as inactive.Tiyazol halkası, birçok alanda biyolojik aktivite oluşturan moleküllerin çekirdeğidir. Bu aktiviteler arasında antikonvülsan, antimikrobiyal, antitüberküloz, antiviral vb. farmakolojik etkiler yer almaktadır. Bu çalışmada sekonder/siklik aminlerden yola çıkılarak tiyazol ve benzimidazol/benzotiyazol/benzofuran/naftofuran halkaları içeren yeni tiyazol türevleri sentezlenmiş ve antimikrobiyal etkileri değerlendirilmiştir. Bileşiklerin sentezinde, sekonder veya siklik aminler tiyoüreye dönüştürülerek 9 bileşik sentezlenmiş ve tiyazol halka kapanması ile devam edilmiştir. Halka kapatma, konvansiyonel yöntemler dışında metilen-karbonil kondenzassyonuyla gerçekleşmiştir. Bileşiklerin karakterizasyonu FT-IR, 1 H NMR ve 13C NMR ve HRMS ile gerçekleştirilmiştir. Bileşikler, bakteri suşları üzerinde önemli aktivite göstermedi. 9 aminotiyazol türevi başarıyla sentezlenmiştir. Bileşikler önemli bir antibakteriyel etki göstermediğinden inaktif olarak tanımlanmıştır

Synthesis, characterization, COX1/2 inhibition and molecular modeling studies on novel 2-thio-diarylimidazoles

Heterocyclic compounds with diaryl substituents have been a milestone approach for selective cyclooxygenase 2 (COX 2) inhibition by bioisosteric replacements and modifications. It is also known that thiazole derivatives have different pharmacological activities. In this study, nine novel 2-[(1,5-diphenyl-1H-imidazole-2-yl)thio]-N-(thiazole-2-yl)acetamide derivatives (Compound 1-9) were synthesized via the reaction of 1,5-disubstitued phenyl-imidazole-2-thiole and N-thiazole acetamide. The inhibitory effects of COX-1 and COX-2 enzymes were tested for the synthesized compounds. Enzyme-ligand interactions of the most active compound on COX subtypes were elucidated by molecular modeling studies. The percent inhibitory effect for compound 1, which is the naked derivative among all the compounds, was found to be the most active on COX-2 at 10 mu M concentration (C1(COX-2): 88%, SC-560(COX-2): 98.2%, C1(COX-1): 60.9%); whereas compound 9 showed the highest inhibitory effect and was found to be the most selective derivative on COX-1 isoenzyme (C9(COX-1): 85%, DuP-697(COX-1): 97.2%, C9(COX-2): 57.9%)

Synthesis, antimicrobial and antioxidant activities of pyridyl substituted thiazolyl triazole derivatives

In this present study, 63 different 5-[4-methyl-2-(pyridin-3/4-yl)thiazole-5-yl]-4-substituted-3-substituted benzylthio-4H-1,2,4-triazole derivatives were synthesized, and evaluated for their in vitro antimicrobial activity against various human pathogenic microorganisms and antioxidant activity. The derivatives were synthesized in a multi-step synthesis procedure including triazole and thiazole ring closure reactions, respectively. The synthesized derivatives (A1-24; B1-39) were screened for their antibacterial, antifungal, and antioxidant activities compared to standard agents. The derivatives possessing 3-pyridyl moiety particularly exhibited relatively high antibacterial activity (MIC= < 3.09-500 µg/mL) against Gram-positive bacteria, and compounds possessing 4-pyridyl moiety showed remarkable antioxidant activity.Eskisehir Osmangazi Universit

Synthesis and characterization of novel oxime derivatives

WOS: 000391709300008Background: The synthesis of effective drugs are very important for the scientist. The various biological effects of the thiazole, oxime and ether functional groups are well known properties by the drug developers. So we have synthesised new molecules which contains three of them on the same molecules. Methods: The acetophenone derivatives have been used for synthesis new oximes. The synthetic pathway includes mainly four steps. sl. alpha-Bromination of acetophenone derivatives, s2. Synthesis of thiazole ring using brominated acetophenones, s3. Synthesis of ethers using synthesised thiazole, s4. Synthesis of oximes. Results: The synthesised molecules characterised using IR, I H-NMR, 13C-NMR and elementel analysis methods. Conclusion: The new oximes which include thiazole and ether groups have been synthesised using acetophenone derivatives.Eskiehir Osmangazi Uni.Research Project Comm. [200819034]This paper supported by Eskiehir Osmangazi Uni.Research Project Comm. with 200819034 project number

Microwave supported synthesis of some novel 1,3-Diarylpyrazino[1,2-a] benzimidazole derivatives and investigation of their anticancer activities

WOS: 000286905400048PubMed ID: 21122952The syntheses of 1,3-diarylpyrazino[1,2-a]benzimidazole derivatives and the investigation of their anticancer activities were studied. For this, 2-aryloylbenzimidazole derivatives were reacted with 2-bromoacetophenones in acetone to give 1-(2-aryl-2-oxoethyl)-2-aryloylbenzimidazoles. The resulting materials were reacted with ammonium acetate in acetic acid to obtain the aimed compound. In this reaction, microwave irradiation method was applied as the reaction conditions. Anticancer activities of the compounds obtained were investigated. It was observed that some of the compounds showed remarkable anticancer activities

Synthesis of some N-[4-(benzothiazole-2yl)phenyl]-2-aryloxyacetamide derivatives and their anticancer activities

WOS: 000306524200007PubMed ID: 21823837In this study, some N-[4-(Benzothiazole-2-yl)phenyl]-2-aryloxyacetamide derivatives were prepared by reacting N-[4-(benzothiazole-2yl)phenyl]-2-chloroacetamide and different substituent phenol or thiophenol derivatives. The anticancer activities of the compounds obtained were investigated. It was observed that some of the compounds, namely 25 and 38, showed notable anticancer activity.Eskisehir Osmangazi University [ESOGU/200819010]This work was supported by the Commission of Scientific Research Projects of Eskisehir Osmangazi University (ESOGU/200819010). The authors gratefully acknowledge the financial support by Eskisehir Osmangazi University. Authors also would like to thank to National Cancer Institue (NCI), Bethesda, MD, USA for in vitro screening of our compounds in human cancer cell lines.Eskisehir Osmangazi Universit

Synthesis and antitumor activity evaluation of new 2-(4-aminophenyl)benzothiazole derivatives bearing different heterocyclic rings

WOS: 000359815200017PubMed ID: 25198890Twenty-five new N-[4-(benzothiazole-2-yl)phenyl]acetamide derivatives bearing different heterocyclic ring systems were synthesized using 2-(4-aminophenyl)benzothiazole structure as a pharmacophoric group. Final compounds were screened for their potential antitumor activity in vitro against approximately 60 human tumor cell lines derived from nine neoplastic diseases at National Cancer Institute, USA. 2-(4-Aminophenyl)benzothiazole structure was prepared by the reaction of 4-aminobenzoic acid and 2-aminothiophenol in polyphosphoric acid using microwave irradiation. After acetylation reaction, amide compounds 2a and 2b were obtained, which were then reacted with 2-mercapto(benz)imidazole/benzothiazole/benzoxazole derivatives in acetone with the presence of potassium carbonate to gain final compounds (3-27). Among all tested compounds, compound 10, namely N-[4-(benzothiazole-2-yl)-3-chlorophenyl]-2-[(benzimidazole-2-yl)thio]acetamide, and compound 16, namely N-[4(benzothiazole-2-yl)phenyl]-2-[(1,5-diphenyl-1H-imidazole-2-yl)thio]acetamide, were found to be of considerable anticancer activity against some cancer cell lines.Commission of Scientific Research Projects of Eskisehir Osmangazi University [ESOGU/200819010]; Eskisehir Osmangazi UniversityThis work was supported by the Commission of Scientific Research Projects of Eskisehir Osmangazi University (ESOGU/200819010). The authors gratefully acknowledge the financial support by Eskisehir Osmangazi University

A quantum chemical DFT/HF study on acidity constants of some benzothiazole and thiazole derivatives

WOS: 000330160400004The acid dissociation (K-a) constants of some 4-and/or 6-substituted-2-aminobenzothiazole compounds have been investigated theoretically. The gas and aqueous phase geometries, thermal and solvation free energies have been calculated with full geometry optimization by using HF (6-31G(d)) and B3LYP (6-31G(d)) methods for 2-aminobenzothiazole, 2-aminothiazole derivatives and their fixed models. From the calculated acidity constants of investigated compounds, it has been detected that the protonation occurs at the the nitrogen atom of the amino group for 2-aminobenzothiazoles and at ring nitrogen atom for 2-aminothiazoles. Acceptable correlations have been observed between theoretically (HF and B3LYP) and experimental pK(a) values of the molecules with regression coefficients (R-2 = 0.98, 0.86) and (R-2 = 0.98, 0.85) for the protonation of benzothiazole and thiazole molecules, respectively. Theoretical calculations also show that basicity of the studied compounds increase in the presence of electron donor substituents

Synthesis and anticancer activity of some 1,2,3-trisubstituted pyrazinobenzimidazole derivatives

WOS: 000345518000007PubMed ID: 24456294The synthesis of some new pyrazino[1,2-a]benzimidazole derivatives and investigation of their anticancer activities were aimed in this work. Thus, 2-acetylbenzimidazole was reacted with appropriate alpha-bromoacetophenones and potassium carbonate in acetone to give 2-(2-acetyl-1H-benzimidazol-1-yl)-1-phenylethanone derivatives (3a-d). These diketone compounds were reacted with varied benzylamines in acetic acid to obtain 2-benzyl-1-methylidene-3-aryl-1,2-dihydropyrazino[1,2-a]benzimidazole derivatives (4a-t). The structures of the obtained compounds were elucidated by using IR, H-1-NMR, C-13-NMR, MS spectral data and elemental analyses results. Anticancer activities of the selected compounds were investigated in National Cancer Institute, Bethesda, MD. 3c and 4n showed remarkable anticancer activity comparing with standard drugs, melphalan and cisplatin