[HDBU][HSO4]-catalyzed facile synthesis of new 1,2,3-triazole-tethered 2,3-dihydroquinazolin-4[1H]-one derivatives and their DPPH radical scavenging activity

Research on Chemical Intermediates - A simple and efficient protocol has been developed for the synthesis of new1,2,3-triazole-2,3-dihydroquinazolin-4[1H]-one (DHQ) conjugates(6a?j) via...     

Synthesis and biological evaluation of novel triazole-biscoumarin conjugates as potential antitubercular and anti-oxidant agents

Research on Chemical Intermediates - The synthesis of a new series of triazole-biscoumarin conjugates by using a molecular hybridization approach is described. The newly synthesized compounds...     

Sodium Bisulfite as an Efficient and Inexpensive Catalyst for the One-pot Synthesis of 2,4,5-Triaryl-1<Emphasis Type="Italic">H</Emphasis>-imidazoles from Benzil or Benzoin and Aromatic Aldehydes

Summary. 2,4,5-Triaryl-1H-imidazoles were efficiently synthesized from benzoin or benzil, ammonium acetate, and aromatic or heteroaromatic aldehydes in the presence of sodium bisulfite as catalyst. The present protocol offers significant improvements for the synthesis of 2,4,5-triaryl-1H-imidazoles with regard to yield of products, simplicity in operation, and cheap catalyst.     

Oxalic acid as a versatile catalyst for one pot facile synthesis of 3,4‐dihydropyrimidin‐2‐(1H)‐ones and their thione analogues

3,4‐Dihydropyrimidin‐2‐(1H)‐ones and their thione analogues are synthesized from the condensation of aromatic aldehydes, β‐dicarbonyl compound and urea or thiourea in presence of 5 mol% of oxalic acid in ethanol‐water (1:2; v/v) under mild reaction conditions. The yields obtained are better and also the use of very inexpensive catalyst, environmentally benign solvent and easy work‐up are the advantageous aspects of the present method.     

Oxalic acld as a catalyst for efficient synthesis of bis-(indolyl)methanes,and 14-aryl-14H-dibenzo[a,j]xanthenes in water

A simple,efficient,and environment benign route was developed for the preparation of bis-(indolyl)methanes and 14-aryl-14H-dibenzo[a,j]xanthenes from condensation of various aromatic aldehydes or ketones with indole,and 2-naphthol,respectively,using oxalic acid catalyst in aqueous medium.Use of cheap and easily available catalyst,better yields and simple reaction protocol are the advantages of the present method.     

Sulfanilic acid catalyzed solvent-free synthesis of 1,5-benzodiazepine derivatives

Sulfanilic acid has been found to be an efficient catalyst for the synthesis of 1,5-benzodiazepines from o-phenylenediamine and ketones. This method is simple, effective and environmentally friendly and gives better yields.     

Oxalic acid catalyzed solvent-free one pot synthesis of coumarins

Oxalic acid was found to be an efficient catalyst for Pechmann condensation,which includes the reaction between phenols andβ-keto esters leading to formation of coumarin derivatives.The advantages of present methods are the use of cheap and easy available catalyst,solvent-free reaction conditions,better yields and shorter reaction time.     

Sodium Bisulfite as an Efficient and Inexpensive Catalyst for the One-pot Synthesis of 2,4,5-Triaryl-1H-imidazoles from Benzil or Benzoin and Aromatic Aldehydes

2,4,5-Triaryl-1H-imidazoles were efficiently synthesized from benzoin or benzil, ammonium acetate, and aromatic or heteroaromatic aldehydes in the presence of sodium bisulfite as catalyst. The present protocol offers significant improvements for the synthesis of 2,4,5-triaryl-1H-imidazoles with regard to yield of products, simplicity in operation, and cheap catalyst.     

Expeditious synthesis,antileishmanial and antioxidant activities of novel 3-substituted-4-hydroxycoumarin derivatives

A series of novel 3-substituted-4-hydroxycoumarin derivatives 6(a–1) were synthesized in high yield using one-pot three component coupling reaction catalyzed by ceric ammonium nitrate. These compounds were evaluated for antileishmanial activity against Leishmania donovani promastigotes and antioxidant activity(DPPH-radical scavenging activity). Two compounds, 6h(IC_(50)= 9.90 μmol/L) and 6i(IC_(50)= 6.90 μmol/L) displayed potent antileishmanial activity when compared with standard antileishmanial agents pentamidine(IC_(50)= 16.15 μmol/L) and miltefosine(IC_(50)= 12.50 μmol/L). Three compounds, 6c(IC_(50)= 10.79 μmol/L), 6h(IC50= 10.60 μmol/L), and 6i(IC_(50)= 10.73 μmol/L) showed significant antioxidant activity favorably with the antioxidant standards butylated hydroxy toluene(IC_(50)= 16.47 μmol/L) and ascorbic acid(IC_(50)= 12.69 μmol/L). A molecular docking study of compounds 6(a–1) suggested a possible mode of binding with the Adenine phosphoribosyltransferase enzyme of L.donovani. ADME properties were predicted in silico and support the potential of 6(a–1) to show favorable drug-like properties.     

ZrOCl2·8H2O catalyzed solvent-free synthesis of isobenzofuran-1（3H）-ones

ZrOCl₂·8H₂O catalyzed environmentally benign synthesis of isobenzofuran-1（3H）-ones are described.ZrOCl₂·8H₂O appeared to be an excellent catalyst for the condensation and reactions.Reaction of phthalaldehydic acid（2-carboxybenzaldehyde） with methylaryl and cyclic ketones was initiated by condensation and occurred in one step providing excellent yields（90-98%）.