Pooja Sapra

Microwave assisted solid support synthesis of novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines as potent antimicrobial agents

An environmentally benign and economic synthesis of 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines is described from readily accessible substituted 2-mercapto-1-amino triazoles and substituted chalcones on basic alumina that are accelerated by exposure to microwaves. The reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating. The method reported herein is devoid of the hazards of solution phase reactions. All the synthesised compounds were tested for their in vitro antibacterial and antifungal activity. Some compounds showed significant antimicrobial properties. The best activity was observed with compounds 3a, 3c, 4a and 4d.

AN EFFICIENT SYNTHESIS OF BENZOPYRANOPYRIMIDINES USING INORGANIC SOLID SUPPORT

ABSTRACT 4-Hydroxycoumarin on reaction with aldehydes in the presence of urea/thiourea using solid inorganic support under microwave irradiation (MWI) afforded 4-substituted benzopyrano [4,3-d]- pyrimidine derivatives in a few seconds with improved yield as compared to conventional heating. This efficient, facile and ecofriendly technique avoids the use of excess solvent and toxic acids usually employed in the process.

MICROWAVE ASSISTED SYNTHESIS OF NOVEL 1,2,4-TRIAZINES IN “DRY MEDIA”

An efficient facile and solventless synthesis of 1,2,4-triazines using microwave is described. A non conventional synthetic procedure has been developed where solid inorganic support is used as energy transfer medium under microwave irradiation (MWI) which devoids hazards of solution phase reactions. The reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating.

A Facile Method for Nucleophilic Aromatic Substitution of Cyclic Amine

Abstract The expeditious solventless nucleophilic aromatic substitution using microwaves is described. A non-conventional synthetic procedure has been developed where basic alumina has been used as energy transfer medium under Microwave Irradiation (MW1). The results were compared with those obtained by the classical method. This rapid and environmentally benign method avoids the use of excess solvents and toxic bases usually employed in the process make this procedure very attractive for synthesis.

Microwave Assisted Stereoselective Synthesis and Antibacterial Activity of New Fluoroquinolinyl-β-lactam Derivatives

Summary. A series of quinoline ring substituted N-(3-chloro-2-(2-fluoro-quinolin-3-yl)-4-oxo-azetidin-1-yl)-octanamides were synthesized from chloroacetyl chloride, octanoic acid, (2-fluoro-quinolin-3-yl-methylene)-hydrazides, and triethylamine using microwave irradiation as well as conventional heating. The reaction time can be brought down from hours to minutes with improved yields using microwave irradiation compared to conventional heating. The compounds were tested for their in vitro antibacterial activity against 2253-Corynebacterium rubrum, 2340-Enterobacter, 2491-Erwinia herbicola, K12-E. coli, and 2873-Z. mobilis. and found to possess activities comparable with or superior to the standard drug ampicillin.Zusammenfassung. Eine Reihe von am Chinolinring substituierten N-(3-Chlor-2-(2-fluorchinolin-3-yl)-4-oxo-azetidin-1-yl)-octanamiden wurden durch Erhitzen der entsprechenden Octansäurehydrazide mit Mikrowellen oder auf konventionelle Weise dargestellt. Die Reaktionszeit wurde durch die Anwendung von Mikrowellen von Stunden auf Minuten reduziert, wobei die Ausbeuten höher lagen. Die Verbindungen wurden auf ihre in vitro-antibakterielle Aktivität gegen 2253-Corynebacterium rubrum, 2340-Enterobacter, 2491-Erwinia herbicola, K12-E. coli und 2873-Z. mobilis getestet. Dabei wurde gefunden, daß ihre Aktivität vergleichbar bzw. besser als jene des Standardwirkstoffs Ampicillin ist.