Chemistery

1983963113, Iran, E-mail: a_bazgir@sbu.ac.ir ... Abstract – A new pyrimido[4,5-d]pyrimidine-2,4-(1H,3H,5H,8H)-dione ... The importance of fused pyrimidines, common source for the development of new potential therapeutic ... With the emphasis on the search for atom-efficient ...

Summary. A simple and efficient method for the synthesis of quinolines and polycyclic quinolines using silica gel supported sodium hydrogen sulfate as reusable eco-friendly catalyst via Friedlnder annulation under solvent-free conditions is described.

A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this procedure are high yields of the products, simple work-up, solvent-free conditions, operational simplicity and non-toxicity of the catalyst. Moreover, cellulose sulfuric acid is successfully reused for four cycles without significant loss of activity.

A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3'-indoline]pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this procedure are high yields of the products, simple work-up, solvent-free conditions, operational simplicity and non-toxicity of the catalyst. Moreover, cellulose sulfuric acid is successfully reused for four cycles without significant loss of activity.

This study was conducted to evaluate the effect of different extraction solvents, including hydro-alcoholic (H-A), ethanolic (Et-OH), and methanolic (Me-OH), on chemical composition and synergistic antibacterial activity of Frangula alnus extract against Staphylococcus aureus and Escherichia coli. The chemical composition of the F. alnus bark extract was evaluated using FTIR, UV-Vis spectroscopy, and GC/MS analysis. The synergistic antimicrobial effect of the extracts with Ciprofloxacin (CIP) and Erythromycin (ERY) was evaluated using minimum inhibitory concentrations, combined disc, and checkerboard titration method. F. alnus contained alkanes, alkenes, phenols, alcohols, esters, terpenes, fatty acid, tetrazole, halo-alkane, anthraquinone as well aromatic, and plasticizer compounds in the ethanolic, methanolic, and hydro-alcoholic extracts. Total phenolic compounds for ethanolic, hydro-alcoholic and methanolic extracts were recorded 110.92±0.01, 95.27±0.01 and 126.6±0.02 g/L Gallic...

The Bronsted acidic ionic liquid ([BMIm]HSO4) catalyzed three-component synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives at room temperature. The integrity of the ionic liquid remains reasonably unchanged when it is separated from the reaction mixture by water extraction, as it can be recycled several times without any loss of activity in each of the title syntheses. The products and ionic liquid could be conveniently separated from the reaction mixture, indicating that the whole process was performed as a green chemical transformation. The salient features of this one pot protocol are short reaction times, cleaner reaction profiles and simple workup.

A green and convenient method for the synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8,13diones and spiro[dibenzo[a,i]-xanthene-14,3'-indoline]-2',8,13-triones is described in the presence of a catalytic amount of cellulose sulfuric acid (CSA) as an efficient biopolymer-based catalyst under solvent-free conditions at 100 °C. The condensation reactions of β-naphtol, 2hydroxynaphthalene-1,4-dione with aldehydes or isatins afforded the corresponding xanthenes in good to excellent yields. To the best of our knowledge, it is the first example of a multicomponent reaction to the synthesis of these compounds using cellulose sulfuric acid. The present approach offers several advantages such as shorter reaction times, simple work-up, excellent yields, non-toxicity of the catalyst, and solvent-free conditions. Moreover, cellulose sulfuric acid is successfully reused for four cycles without significant loss of activity.

A practical and new method for the synthesis of oxindole substituted pyrrolo[2,3 d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °C was described. The reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3 d]pyrimidines in good to excellent yields. All reactions performed efficiently under ultrasound irradiation and results were compared with conventional heating method. In this field, several types of acetophenones, amino-uracils, and isatins were rapidly changed to the corresponding derivatives. The remarkable features of the new procedure are shorter reaction time, excellent yields, cleaner reaction profile, and simple experimental and workup procedure.