چكيده فارسي :
Tetrazoles are an important category of nitrogen containing heterocycles with a wide range of biological properties such as antimicrobial, antibacterial, antifungal, analgestic,anti-inflammatory, antiviral, and anti-cancer activities. Tetrazoles are widely used in many drugs such as sartan family drugs(Candesartan and Losartan) and antihistaminic drugs(Pemiroplast and Pranlukast) information recording systems, highdensityenergy materials, antifoggants in photography,ligands in coordinationchemistry , propellants and explosives .The synthesis of 5-substituted 1H-tetrazoles was first reported by Hantzsch and Vagt in 1901, which is based on [3 ,2] cycloaddition of azide with organic nitriles and its chemistry has been developed from 1980.
Generally, 5-substituted 1H-tetrazoles are prepared by the addition of azides to nitriles but some of the methods suffer from usual drawbacks such as long reaction time, expensive reagents, stoichiometric amounts of catalysts, strong Lewis acids, low yield and water sensitivity. Magnetic nanocatalystFe3O4@SiO2.SnCl4 is an effective heterogeneous catalyst for the [2 ,3]-cycloaddition of sodium azide with nitriles to afford 5-substituted 1H-tetrazoles in good yields.
A simple, safe and efficient method is developed for the synthesis of 5-substituted 1H-tetrazoles. The catalyst is reusable up to three cycles with consistent activity. The cost effectiveness and easy availability of the catalyst, simple method, excellent yield and easy work-up are the additional advantages of this protocol.
