Cetyltrimethylammonium Bromide as an Efficient Catalyst for Regioselective Bromination of Alkoxy Naphthalenes with Trimethyl Benzyl Ammonium Tribromide: Synthetic and Kinetic Approach

Bromination of 2‐alkoxynaphthalene (2‐ANP) and its derivatives with trimethyl benzyl ammonium tribromide (TMBATB) did not proceed smoothly even under reflux conditions. But the addition of microconcentrations of cetyltrimethyl ammonium bromide (CTAB) to the reaction afforded dramatic rate accelerations as well as good‐to‐excellent yield of the products ranging from 70% to 90%. Reactions underwent regioselective monobromination at 1‐position of 2‐alkoxynaphthalene. The rate of bromination has been followed conductometrically. The reaction kinetics indicated first‐order kinetics in [2‐ANP] as well as in [TMBATB]. Kinetic results in the presence of CTAB were explained on the basis of the Raghavan–Srinivasan model as applied to micelle‐mediated bimolecular reactions.     

Synthesis of 1H‐Imidazoles Catalyzed by Cu‐Nanoparticle and Its Physicochemical Properties

Series of 1‐arylmethyl‐4, 5‐dihydro‐2‐aryl‐1H‐imidazole were synthesized expeditiously in good yields from 1,2‐diaminoethane and aromatic aldehydes in the presence of Cu nanoparticle under microwave irradiation in solvent‐free method. Monodisperse spherical Cu nanoparticles with a diameter range of 45 ± 8 nm were synthesized by polyol process. The particle size and elemental structure of copper nanoparticles were confirmed by XRD data and was found to be having a face‐centered cubic structure. The resulting substituted imidazoles have been studied in the achievement of degree of drug absorption enhancement as well as the potential associated toxicity on the basis of hypothetical antibacterial pharmacophores and structures that were designed to interact with both of gram‐positive and gram‐negative bacteria. All the synthesized molecules were characterized on the basis of 1H NMR, 13C NMR, mass spectrometry, and elemental data.     

Synthesis and Antimicrobial Studies of Novel Imidazole Containing Bisazetidinones and Bisthiazolidinone Derivatives

A simple, practical, and efficient approach to new series of imidazole containing bisazetidinones ( 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j and 9a , 9b , 9c , 9d , 9e , 9f , 9g , 9h , 9i , 9j ) was prepared by Staudinger [2 + 2] cycloaddition reaction, and bisthiazolidinones ( 8a , 8b , 8c , 8d , 8e , 8f , 8g , 8h , 8i , 8j and 10a , 10b , 10c , 10d , 10e , 10f , 10g , 10h , 10i , 10j ) were obtained by cyclization of bisimines with thioglycolic acid. The bisimines ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j and 6a , 6b , 6c , 6d , 6e , 6f , 6g , 6h , 6i , 6j ) were synthesized by the condensation of 3‐(1‐(3‐aminobenzyl)‐4, 5‐dihydro‐1H‐imidazol‐2‐yl) aniline ( 3 , 4 ) with a series of different substituted aromatic aldehydes. All the newly synthesized target compounds were evaluated for their in vitro antimicrobial activity against two Gram‐positive bacteria and two Gram‐negative bacteria. Additionally, these synthesized compounds were tested for their antifungal activities. Few compounds showed very good antibacterial and antifungal activity.     

Benzyltrimethylammonium Dichloroiodate Catalyzed Four‐Component Synthesis of Fully Functionalized Pyrroles Under Eco‐compatible Conditions

Benzyltrimethylammonium dichloroiodate promoted an eco‐compatible synthesis of fully functionalized pyrroles via isocyanide‐based four‐component reactions under solvent‐free conditions that are reported. Benzyltrimethylammonium dichloroiodate supported reaction process including Knoevenagel condensation followed by the Michael type and intramolecular cyclization that gives high yields.     

Kinetics and Mechanism of Certain Acetylation Reactions with Acetamide/Oxychloride in Acetonitrile under Vilsmeier?Haack Conditions

Vilsmeier? Haack (VH) acetylation reactions with benzaldehydes or acetophenones in MeCN followed second‐order kinetics and afforded acetyl derivatives under kinetic conditions, irrespective of the nature of the oxychloride (SOCl₂ or POCl₃) used for the preparation of the VH reagent along with acetamide. The present finding contributes to the understanding of the nature of the reactive species of the VH reagent as well as of the acetylation mechanism.     

Metal free Lewis acid promoted one-pot synthesis of 14-aryl-14H dibenzo [a,j] xanthenes and their simple biological evolution

A green, competent one-pot synthesis of 14-aryl 14H-dibenzo [a,j] xanthene and its bio-computational studies are reported. Target compounds are prepared by the condensation of 2-naphthol with benzaldehyde and its substituents using metal free benzyltrimethylammonium tribromide (BTMA-Br₃) catalyst under solvent free thermal and microwave conditions. This technique has more advantages such as high yield, a clean procedure, low reaction time, simple workup and mild Lewis organo acid catalyst.     

Synthesis and Antimicrobial Evaluation of New Monocyclic β‐Lactams

A simple, practical, and efficient approach to synthesize new series of 2‐(3‐(2,4‐dichlorophenoxy)‐2‐(4‐(dimethylamino)phenyl)‐4‐oxoazetidin‐1‐ylamino)‐N‐arylacetamide by Staudinger [2 + 2] cycloaddition reaction. The titled compounds were evaluated for their antibacterial and antifungal activity against eight microorganisms. All the newly synthesized compounds are characterized by IR, ¹H‐NMR, and mass spectroscopic data.