A novel approach for the synthesis of 5-substituted-1H-tetrazoles

Abstract

Uma série de 1H-tetrazóis-5-substituídos (RCN 4 H) foi sintetizada pela reação de cicloadição de diferentes aril e alquil nitrilas com azida de sódio em DMSO, usando CuSO 4 •5H 2 O como catalisador. Uma grande variedade de aril nitrilas sofreu cicloadição [3+2], obtendo-se os correspondentes tetrazóis sob condições reacionais brandas. O catalisador utilizado é obtido facilmente e ambientalmente correto. Tempos de reação curtos, bons a excelentes rendimentos, processo seguro e simples tornam este método uma contribuição atrativa e útil à presente síntese orgânica de 1H-tetrazóis-5-substituídos.A series of 5-substituted-1H-tetrazoles (RCN 4 H) have been synthesized by cycloaddition reaction of different aryl and alkyl nitriles with sodium azide in DMSO using CuSO 4 •5H 2 O as catalyst. A wide variety of aryl nitriles underwent [3+2] cycloaddition to afford tetrazoles under mild reaction conditions in good to excellent yields. The catalyst used is readily available and environmentally friendly. Short reaction times, good to excellent yields, safe process and simple workup make this method an attractive and useful contribution to present organic synthesis of 5-substituted-1H-tetrazoles.Keywords: 5-substituted-1H-tetrazole, arylnitriles, sodium azide, CuSO 4 •5H 2 O, cycloaddition reaction IntroductionThe chemistry of heterocyclic compounds has been an interesting field of study for a long time. Tetrazoles as a group of heterocyclic compounds are reported to possess a broad spectrum of biological activities such as antibacterial, 1 antifungal, 2 antiviral, 3-5 analgesic, 6,7 anti-inflammatory, [8][9][10] [41][42][43][44][45][46][47][48] were commonly used to improve the catalytic abilities of montmorillonites. These methods require a large excess of sodium azide, longer reaction time, and expensive metals. Moreover, the cycloaddition is too slow A Novel Approach for the Synthesis of 5-Substituted-1H-tetrazoles J. Braz. Chem. Soc. 2198 to be synthetically useful except when strong electronwithdrawing groups activate the nitrile compounds.Today's stringent environmental and legislative concerns demand for the green methods that reduce the use of toxic and corrosive reagents and stop the formation of inorganic wastes. 49 However, it has been also observed that the catalysts employed are not always eco-friendly and because of this, serious environmental pollution often results. Therefore, in the area of green synthesis, the development of environmentally friendly alternatives is desirable for the synthesis of tetrazoles. 50 Recently, we have studied the application of cupric sulfate pentahydrate in the trimethylsilylation of alcohols and phenols, 51 and perceived that cupric sulfate pentahydrate as a mild Lewis acid, which is readily available, might be a useful catalyst for the synthesis of 5-substituted-1H-tetrazoles. In this paper we report a new process for the synthesis of 5-substituted 1-H-tetrazoles using cupric sulfate pentahydrate as a safe, environmentally benign, and inexpensive catalyst. ExperimentalThe p...

Copper immobilized on aminated ferrite nanoparticles by 2‐aminoethyl dihydrogen phosphate (Fe3O4@AEPH2‐CuII) catalyses the conversion of aldoximes to nitriles

“…In continuation of our recent studies of the application of Cu II in organic reactions, after preparation and characterization of Fe 3 O 4 @AEPH 2 ‐Cu II , its catalytic activity as a new magnetic nanocatalyst was investigated in the preparation of a library of nitriles through dehydration of aldoximes by acetonitrile (Scheme ).…”

facile, highly efficient and novel method for synthesis of 5-substituted 1H-tetrazoles catalysed by copper(I) chloride

“…Also, the IR spectra of all the products showed bands at 1515-1606 cm −1 due to (N--N) (Özkan et al, 2007) Brought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 5/30/15 8:25 AM v due to (N-N--N-) (Akhlaghinia & Rezazadeh, 2012). From analysing the 13 C NMR spectra of all the products, the signals at δ 157-155 correspond to the quaternary carbon of the tetrazole ring (NH-C--N).…”

Microwave assisted synthesis of 1H-tetrazole-based flavonoid derivatives and their antimicrobial activity

“…IR (KBr) spectra were recorded on a Shimadzu FTIR-8400S spectrophotometer. 1 H-NMR and 13 C-NMR spectra were measured on a Bruker 4-(1H-Tetrazol-5-yl)benzaldehyde 34 (2) Sodium azide (1 mmol) and cupric sulfate pentahydrate (2 mol %) were added to a stirred solution of 4-formylbenzonitrile 1 (1 mmol) in DMSO (2 mL) at room temperature. The reaction mixture was then heated at 140 °C for 1 h (Scheme 1).…”