- Combustion characteristics of EMOFs/oxygenated salts novel thermite for green energetic applications
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Metal-based thermites, especially those based on aluminum, have been recently included in materials for energetic applications such as pyrotechnics, propellants, and explosives. In parallel, several advances in the field of Metal-Organic Frameworks (MOFs) and Coordination Polymers (CPs) have as well paved the road for their use in developing novel energetic materials. In this context, we are introducing new thermites compositions with low ignition temperature, stable propulsive force, and high reactivity. These thermites are based on the [Cu4Na(Mtta)5(CH3CN)]n (Mtta = 5-Methyl-1H-tetrazole) energetic metal-organic framework (EMOF-1) as a fuel instead of pure metals. We first report the synthesis of an energetic MOF via the microwave-assisted technique as a more rapid and greener method. The efficiency of composites based on EMOF-1 and Al together with various oxygenated salts were investigated. Multiple instruments are involved to characterize the morphology and the structure of EMOF-1 and the developed systems, such as SEM-EDX, FTIR, and XRD. The combustion behavior of the novel composites was evaluated by TGA/DSC, bomb calorimetry and laser ignition. Additionally, the apparent kinetic parameters (activation energy & frequency factor) were calculated by the Kissinger and Ozawa approaches. The results revealed that the new thermite mixtures exhibit superior combustion characteristics of one and half to two-folds the average heat of combustion compared to aluminum-based ones, at almost half the ignition temperature. In this sense, the combustion reaction proceeds faster, easier (reduced activation energy), the ignition temperatures are noticeably lowered, and the heat released has considerably improved. In addition, they exhibited stable force with longer burning time. Among them, EMOF-1/KIO4 thermite exhibits the highest heat release (4.7 kJ/g), while EMOF-1/NH4NO3 thermite shows the lowest onset reaction temperature (224 ?C). EMOF-1/KClO4 yields the highest average force (8.4 N), calculated pressure (1365 kPa), pressurization rate (0.32 kPa/μs) and the longest burning time assigned to EMOF-1/K2S2O8 (40 ms).
- Boffito, Daria C.,Chaouki, Jamal,Dubois, Charles,Fahd, Ahmed,Wen, John Z.,Zorainy, Mahmoud Y.
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Read Online
- Synthesis, structural and computational studies of new tetrazole derivatives
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Herein, we report a synthesis of two new disubstituted tetrazoles, 2-(2,4-dinitrophenyl)-5-methyl-2H-tetrazole (2) and 1-(2,4-dinitrophenyl)-5-methyl-1H-tetrazole (3). The products were characterized by 1H and 13C NMR spectroscopy, as well as single-crystal X-ray diffraction. The intermolecular interactions in the crystals were investigated by Hirshfeld surface analysis, 2D fingerprint plots, and noncovalent interaction analysis (NCI). Tetrazole rings of both compounds were found to be involved in both strongest attractive and repulsive intermolecular interactions. DFT calculations were performed using the PW6B95-D3(BJ)/def2-TZVP level of theory in order to obtain information about the molecular electrostatic potential (MEP), and global and local reactivity (dual descriptor) indices of the studied tetrazoles. The calculated molecular electrostatic potentials correlated well with the Hirshfeld surface and NCI plots. The 1,5-disubstituted tetrazole exhibited lower kinetic stability and was slightly more electrophilic than the 2,5-regioisomer. The dual descriptor index was used to reveal electrophilic and nucleophilic sites for both molecules.
- Klisuri?, Olivera R.,Oklje?a, Aleksandar M.
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- Igneous rock powder as a heterogeneous multi-oxide nano-catalyst for the synthesis of 5-substituted-1H-tetrazoles in polyethylene glycol
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The use of igneous rock nano-powder as a heterogeneous and recyclable multi-oxide nano-catalyst synthesizing of 5-substituted-1H-tetrazoles is reported. The igneous rock nano-powder was initially prepared by using the ball-milling method. Then, the structure, morphology, and magnetic properties of the prepared igneous rock nano-powder were characterized with some different spectroscopic, microscopic, and thermogravimetric techniques, such as FTIR, FESEM, XRF, XRD, Histogram, and EDS. The instrumental analyses showed that the prepared igneous rock powder is a mixture of metal oxides, such as Si, Al, Ca, Mg, Fe, Na, Mn, and Sr. It showed an excellent catalytic performance in synthesizing of 5-substituted-1H-tetrazoles through [3 + 2] cycloaddition reaction between sodium azide and nitrile compounds. Various aliphatic and aromatic nitriles and sodium azide were reacted in the presence of a catalytic amount of igneous rock nano-powder at 80 o C temperature in PEG-400. The protocol was simple and rapid, with suitable yields of the obtained tetrazoles. The igneous rock nano-powder is readily accessible, reusable, and holds potential for further application in acid-catalyzed organic syntheses and industrial requirements. Graphic abstract: [Figure not available: see fulltext.]
- Javaherian, Mohammad,Movaheditabar, Parviz,Nobakht, Valiollah
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- Catalytic conversion of 2,4,5-trisubstituted imidazole and 5-substituted 1H-tetrazole derivatives using a new series of half-sandwich (η6-p-cymene)Ruthenium(II) complexes with thiophene-2-carboxylic acid hydrazone ligands
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A new series of half-sandwich (η6-p-cymene) ruthenium(II) complexes with thiophene-2-carboxylic acid hydrazide derivatives [Ru(η6-p-cymene)(Cl)(L)] [L = N'-(naphthalen-1-ylmethylene)thiophene-2-carbohydrazide (L1), N'-(anthracen-9-ylmethylene)thiophene-2-carbohydrazide (L2) and N'-(pyren-1-ylmethylene)thiophene-2-carbohydrazide (L3)] were synthesized. The ligand precursors and their Ru(II) complexes (1–3) were structurally characterized by spectral (IR, UV–Vis, NMR and mass spectrometry) and elemental analysis. The molecular structures of the ruthenium(II) complexes 1–3 were determined by single-crystal X-ray diffraction. All complexes were used as catalysts for the one-pot three-component syntheses of 2,4,5-trisubstitued imidazole and 5-substituted 1H-tetrazole derivatives. The catalytic studies optimized parameters as solvent, temperature and catalyst. The catalysts revealed very active for a broad range of aromatic aldehydes presenting either electron attractor or electron donor substituents and, although less active, moderate to high activities were observed for alkyl aldehydes.
- Vinoth, Govindasamy,Indira, Sekar,Bharathi, Madheswaran,Archana, Govindhasamy,Alves, Luis G.,Martins, Ana M.,Shanmuga Bharathi, Kuppannan
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- TMSN3-Bu2Sn(OAc)2: A modified and mild reagent system for Wittenberger tetrazole-synthesis
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Treatments of various nitriles with TMSN3 and Bu2Sn(OAc)2 at 30 °C in benzene for 60 h yielded the corresponding 5-substituted 1H-tetrazoles in good to excellent yields. This method is a mild and efficient alternative reagent system for Wittenberger tetrazole-synthesis that uses TMSN3 and Bu2SnO in toluene at high temperature (93–110 °C) for 24–72 h.
- Yoneyama, Hiroki,Oka, Naoki,Usami, Yoshihide,Harusawa, Shinya
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- A 5 - substituted four nitrogen azole compound of synthetic method (by machine translation)
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The invention discloses a 5 - substituted four nitrogen azole compound of synthetic method, the synthesis method of the process is as follows: to point pen in the autoclave (I) indicated by the nitrile compounds, sodium azide, nickel ferrite and carboxylic acid ammonium ion exchange resin, added with an organic solvent to the cyclization reaction, the reaction solution after the reaction is finished filter, pickling, desolvation and heavy after crystallization, as shown in formula (II) of the 5 - substituted tetrazole compounds, yield is 85 - 95%, purity ≥ 99%; Formula (I) in the formula (II), the substituent R1 Is phenyl, substituted phenyl, C1 - C3 alkyl or amino; substituted phenyl substituent is methyl, methoxy, F or nitro. The invention of 5 - substituted tetrazole compounds synthesis method, adopt the catalytic ferrous acid nickel and carboxylic acid ammonium ion exchange resin catalyst combination, the carboxylic acid [...], not only good general the reaction substrate, the reaction yield is high, and the catalyst is easily separated and recycled, the production cost is reduced and the three waste emissions. (by machine translation)
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Paragraph 0016; 0017; 0018
(2019/04/04)
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- Batch Versus Flow Lithiation–Substitution of 1,3,4-Oxadiazoles: Exploitation of Unstable Intermediates Using Flow Chemistry
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1,3,4-Oxadiazoles are a common motif in pharmaceutical chemistry, but few convenient methods for their modification exist. A fast, convenient, high yielding and general α-substitution of 1,3,4-oxadiazoles has been developed using a metalation-electrophilic trapping protocol both in batch and under continuous flow conditions in contradiction to previous reports which suggest that α-metalation of this ring system results in ring fragmentation. In batch, lithiation is accomplished at an industrially convenient temperature, ?30 °C, with subsequent trapping giving isolated yields of up to 91 %. Under continuous flow conditions, metalation is carried out at room temperature, and subsequent in flow electrophilic trapping gave up to quantitative isolated yields. Notably, lithiation in batch at room temperature results only in ring fragmentation and we propose that the superior mixing in flow allows interception and exploitation of an unstable intermediate before decomposition can occur.
- Wong, Jeff Y. F.,Tobin, John M.,Vilela, Filipe,Barker, Graeme
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supporting information
p. 12439 - 12445
(2019/09/06)
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- Application of Photoclick Chemistry for the Synthesis of Pyrazoles via 1,3-Dipolar Cycloaddition between Alkynes and Nitrilimines Generated In Situ
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The photochemical extrusion of gaseous nitrogen from 2,5-disubstituted tetrazoles to generate reactive nitrilimines in situ represents an efficient and attractive way to form dipoles that can be used to provide useful chemicals via 1,3-dipolar cycloadditions. The concept of “photoclick chemistry” already inspired numerous researchers, who exploited photochemical processes involving alkenes for the synthesis of adducts or the functionalization of biocompatible materials. The approach requires bioorthogonality, ease of access to the starting materials and operational simplicity. We report herein our investigations toward a photoclick reaction involving 2,5-disubstituted tetrazoles and alkynes as the dipolarophile for the synthesis of pyrazole derivatives. In addition to the numerous reports recently published on the synthesis of pyrazoles, we wish to add to the list a photochemical procedure that represents a mild and atom-economical alternative. Moreover, considering that such nitrilimines precursors can be accessed in one step from inexpensive and abundant starting materials and given the commercial availability of a broad spectrum of alkynes, we examined the scope of the photoclick reaction with respect to reactive partners, enabling the synthesis of a library of useful heteroaromatics.
- Remy, Richard,Bochet, Christian G.
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p. 316 - 328
(2018/01/27)
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- [3 + 2] Cycloaddition promoted by zinc oxide nanoparticles anchored on reduced graphene oxide using green solvent
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ZnO anchored on RGO-catalyzed [3 + 2] cycloaddition of nitriles and sodium azide in the synthesis of 5-substituted 1H-tetrazoles in water is an efficient and simple protocol with low catalyst loading under reflux condition. It is applied to a wide range of substrates with an excellent yield, simple workup procedure, recovery, and reusability of catalyst with consistent activity and high turnover number. It is proposed that the functional groups present in RGO surface are effective for preventing the aggregation of catalytically active ZnO species during the reaction. Moreover, the excellent performance of ZnO–RGO nanocomposite is ascribed to the excellent dispersity of catalyst in water, hydrophilic nature of the RGO for the accumulation of organic substrates in water, and the “Breslow effect.”.
- Clarina, Thanaraj,Rama, Velladurai
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supporting information
p. 175 - 187
(2018/01/01)
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- A zinc Lewis acid surface active agent for the preparation of 5' - substituted tetrazole compounds
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The invention belongs to the field of organic synthetic technology, and specifically relates to a zinc Lewis acid surfactant as catalysts for preparing the 5' - substituted compound four azole class method. The method comprises the following steps: 1) to zinc Lewis acid surfactant Zn (OSO2 Cn H2 N + 1 )2 As the catalyst, R cyanide and sodium azide in water reaction to obtain the 5' - R base four nitrogen zuo compound of zinc salt and by-product NaOSO2 Cn H2 N + 1 ; 2) In the step 1) of the obtained 5 '- R base four nitrogen zuo compound of zinc salt in the acidification is carried out under acidic conditions, to obtain the 5' - R base four nitrogen zuo compounds and by-product zinc bromide; 3) by-product NaOSO2 Cn H2 N + 1 And by-product zinc bromide in the substitution reaction under acidic conditions, to obtain zinc Lewis acid surfactant Zn (OSO2 Cn H2 N + 1 )2 . Method can be used in "one-pot" strategy, the starting material by continuous cyclization reaction, the acidification reaction directly preparation containing the tetrazole compound of the structural unit; the method used in the zinc Lewis acid surfactant can be recovered after the reaction.
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Paragraph 0136-0144
(2018/09/08)
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- Binary Polyazides of Cerium and Gadolinium
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Herein, we report on the preparation and full characterization (melting point, ATR-IR/Raman, elemental analysis, 14N NMR) of binary gadolinium(III) azide as DMSO solvate Gd(N3)3·8/3DMSO (DMSO = dimethylsulfoxide), along with the partially hydroxide substituted species Gd4(OH)2(N3)10·nDMSO (n = 8, 10). Moreover, the isolation and comprehensive characterization of hexaazido lanthanate(III) anions [Ln(N3)6]3– (Ln = Ce, Gd) in a series of [Ph4P]+ and [EtPh3P]+ salts is presented. Single-crystal structures of all compounds were determined, and the magnetic susceptibility in solution (NMR, Evans Method), as well as in the solid state (VSM), was investigated.
- Rosenstengel, Kati,Schulz, Axel,Niehaus, Oliver,Janka, Oliver,P?ttgen, Rainer,Villinger, Alexander
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supporting information
p. 778 - 790
(2018/02/09)
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- A METHOD OF PREPARING 5-ALKYLTETRAZOLE
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The present invention relates to a method of preparing 5-alkyltetrazole which comprises the following steps: a) reacting alkyl imidate represented by chemical formula 1 with a1) hydrazine to obtain a compound represented by chemical formula 2; a2) reacting the compound represented by the chemical formula 2 with a nitrite compound and acid, to obtain a reaction mixture; and b) reacting the reaction mixture with a base to obtain 5-alkyltetrazole represented by chemical formula 3.COPYRIGHT KIPO 2018
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Paragraph 0068-0071; 0074-0076
(2018/05/03)
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- Syntheses of 5-substituted 1H-tetrazoles catalyzed by reusable Cu(II)-NaY zeolite from nitriles
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Cu(II)-NaY heterogeneous catalyst is used for the synthesis of 5-substituted 1H-tetrazoles by [2+3]-cycloaddition of sodium azide and nitriles. The salient features of this process are low reaction times, mild reaction conditions and high yields. The catalyst is recovered and reused for several cycles with consistent activity.
- Sudhakar,Purna Chandra Rao,Prem Kumar,Suresh,Ravi
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p. 864 - 866
(2017/02/10)
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- Synthetic method of 5-(C1~C4 alkyl) tetrazole
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The present invention relates to a process for the preparation of a synthesis method of 5-(C1-C4 alkyl) tetrazole, which is characterized in that C1-C4 alkyl nitrile and an azide compound are reacted under at least one catalyst selected from zinc acetate and zinc sulfate. According to the above method, the yield can be improved and the manufacturing cost can be reduced.COPYRIGHT KIPO 2018
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Paragraph 0047-0048
(2018/04/06)
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- Synthetic method of 5-(C1~C4 alkyl) tetrazole
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The present invention relates to a synthesis method of 5-(C1-C4 alkyl) tetrazole characterized in that C1-C4 alkyl nitrile and an azide compound are reacted under the presence of a C1-C4 alkylcarboxylic acid catalyst. According to the method of the present invention, an expensive production facility such as a high-pressure reactor is not required, the catalyst can be easily removed, and the yield can be greatly improved, thereby greatly reducing the manufacturing costs.COPYRIGHT KIPO 2017
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Paragraph 0040-0041; 0044
(2018/02/21)
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- Process for Preparing 5-Alkyltetrazole
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The present invention provides a method for preparing 5-alkyl tetrazole comprising a step of reacting a nitrile compound with a hydrazine or salt thereof in the presence of organic acid, a step of adding nitrite or salt thereof to the mixture, and a step of adding a base to the mixture for reaction. According to the preparing method of the present invention, 5-alkyl tetrazole can be produced at a high yield under mild reaction conditions.COPYRIGHT KIPO 2017
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Paragraph 0037; 0038; 0040; 0042; 0044
(2018/02/08)
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- Synthesis of 5-substituted 1H-tetrazoles using a recyclable heterogeneous nanonickel ferrite catalyst
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An efficient method was developed for the [2 + 3] cycloaddition of sodium azide with nitriles to afford 5-substituted 1H-tetrazoles using nanonickel ferrite (NiFe2O4) as an effective heterogeneous catalyst in dimethylformamide. The main advantages of this method are high yields, simple methodology and easy work-up. The catalyst can be recovered and reused for several cycles with predictable activity.
- Abrishami, Fatemeh,Ebrahimikia, Maryam,Rafiee, Fatemeh
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p. 730 - 735
(2015/11/09)
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- Rectangular ZnO porous nano-plate assembly with excellent acetone sensing performance and catalytic activity
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The controlled synthesis of a hierarchically assembled porous rectangular ZnO plate (2.5-3.5 μm length, 1.5-2.5 μm width and 100-150 nm thickness) from bulk ZnO without using any organic substrates, such as solvents/surfactants/structure-directing agents, is presented. The synthesized ZnO plates are single crystalline with exposed (1010) facets on the flat surface, porous and formed through the calcination of a hydrozincite [Zn5(CO3)2(OH)6] intermediate. A gas sensor based on the synthesized porous ZnO architecture exhibited high sensitivity towards acetone even in low concentration (S = 3.4 in 1 ppm acetone) with good selectivity. The ZnO nanostructured material as a heterogeneous catalyst also showed excellent catalytic activity for the synthesis of 5-substituted-1H-tetrazoles (yield = 94%). Both the activities are superior than those of other reported ZnO based acetone sensors and heterogeneous catalysts. We believe that the improved properties of the synthesized ZnO nanostructure is due to the exposed (1010) facets, and its porous and assembled structure, which provides a reasonably large accessible surface area, and facilitates diffusion and mass transport of gas or substrate molecules.
- Giri, Arnab Kanti,Saha, Arka,Mondal, Aniruddha,Chandra Ghosh, Subhash,Kundu, Susmita,Panda, Asit Baran
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p. 102134 - 102142
(2015/12/11)
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- Reductive removal of the pivaloyl protecting group from tetrazoles by a naphthalene-catalyzed lithiation process
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The reaction of various 1-pivaloyl-1H-tetrazoles with excess lithium and a catalytic amount of naphthalene (20 mol%) led, after treatment with methanol, to the corresponding free tetrazoles through reductive C-N bond cleavage. This methodology represents a reasonable alternative to other nonreductive protocols.
- Behloul, Cherif,Chouti, Aicha,Guijarro, David,Nájera, Carmen,Yus, Miguel
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supporting information
p. 507 - 510
(2015/02/19)
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- Detritylation of protected tetrazoles by naphthalene-catalyzed lithiation
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Treatment of N-tritylated tetrazoles bearing aliphatic, aromatic, or heteroaromatic substituents (including functionalized ones) with lithium powder and a catalytic amount of naphthalene led to reductive removal of the trityl group to give excellent yields of the corresponding free tetrazoles without decomposition of the tetrazole ring. The detritylation process was successfully extended to several tetrazoles that are components of sartans, an interesting class of drugs. The chemoselectivity between trityl-tetrazole and trityl-amine bond-cleavage reactions was also studied. This method represents an efficient technique for deprotection of tritylated tetrazoles under non-acidic conditions. Georg Thieme Verlag Stuttgart, New York.
- Behloul, Cherif,Bouchelouche, Kenza,Guijarro, David,Nájera, Carmen,Yus, Miguel
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p. 2065 - 2070
(2014/08/05)
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- Self-healing and moldable material with the deformation recovery ability from self-assembled supramolecular metallogels
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A self-assembled non-covalent metallogel system with self-healing, deformation recoverable, moldable and bottom-up load-bearing properties was prepared using tetrazolyl derivatives and Pd(OAc)2. This journal is
- Yan, Liwei,Gou, Shaohua,Ye, Zhongbin,Zhang, Shihong,Ma, Lihua
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supporting information
p. 12847 - 12850
(2015/02/18)
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- An improved protocol for the preparation of 5-substituted tetrazoles from organic thiocyanates and nitriles
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Organic thiocyanates and nitriles are converted efficiently into the corresponding 5-substituted 1H-tetrazoles by treatment with zinc(II) chloride and sodium azide in aliphatic alcohols. The presented procedure provides mild reaction conditions, short reaction times, and good to excellent yields for a wide range of substrates, including deactivated aliphatic nitriles and thermally unstable thiocyanates. Georg Thieme Verlag Stuttgart · New York.
- Vorona, Svetlana,Artamonova, Tatiana,Zevatskii, Yuri,Myznikov, Leonid
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p. 781 - 786
(2014/04/03)
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- Amberlyst-15 catalyzed synthesis of 5-substituted 1-H-tetrazole via [3+2] cycloaddition of nitriles and sodium azide
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A mild and efficient method for the preparation of 5-substituted 1-H-tetrazole derivatives is reported using solid acidic resin Amberlyst-15 as an effective heterogeneous catalyst. This method is advantageous because of non-toxicity and stability of catalyst, high product yield, simple methodology, and easy work up. The catalyst was recovered by simple filtration and reused several times delivering moderate to good product yield.
- Shelkar, Radheshyam,Singh, Abhilash,Nagarkar, Jayashree
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p. 106 - 109
(2013/02/21)
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- A rapid and green synthetic approach for hierarchically assembled porous ZnO nanoflakes with enhanced catalytic activity
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Three dimensionally (3D) assembled hierarchical porous ZnO structures are of key importance for their applications in sensors, lithium-ion batteries, solar cells and in catalysis. Here, the controlled synthesis of 3D hierarchically porous ZnO architectures constructed of two dimensional (2D) nano-sheets through the calcination of a hydrozincite [Zn5(CO 3)2(OH)6] intermediate is presented. The intermediate 3D hierarchical hydrozincite has been synthesized by a novel organic surfactant and solvent free aqueous protocol at room temperature using an aqueous solution of ammonium carbonate and laboratory grade bulk ZnO in a short time (20-30 min). The amount of carbonate and the reaction temperature play a crucial role in the formation of the 3D hierarchical morphology and on the basis of the experimental results a probable reaction mechanism is proposed. On calcination, the synthesized 3D hierarchical hydrozincite resulted in ZnO with an almost identical morphology to the parental hydrozincite. On decomposition a porous structure having a surface area of 44 m2 g-1 is obtained. The synthesized hierarchical ZnO morphology exhibits an improved catalytic activity for the synthesis of 5-substituted-1H-tetrazoles with different nitriles and sodium azide than that of nanocrystalline ZnO and bulk ZnO, as well as other developed solid catalysts. The catalyst is easily recyclable without a significant loss in catalytic activity. The Royal Society of Chemistry 2012.
- Sinhamahapatra, Apurba,Giri, Arnab Kanti,Pal, Provas,Pahari, Sandip Kumar,Bajaj, Hari C.,Panda, Asit Baran
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p. 17227 - 17235
(2012/11/07)
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- Syntheses of 5-substituted 1 H-tetrazoles catalyzed by reusable CoY zeolite
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A simple and efficient route for the synthesis of 5-substituted 1H-tetrazoles catalyzed by CoY zeolite is reported. The salient features of this atom-economical, cost-effective, and high-yield cobalt-catalyzed protocol are aerobic conditions, lower reaction time, and milder reaction conditions without additives. Other advantages include experimental ease of manipulation, safer alternative to hazardous, corrosive, and polluting conventional Lewis acid catalysts, recovery, and reusability with consistent catalytic activity. The results are rationalized by proposing a suitable mechanism.
- Rama, Velladurai,Kanagaraj, Kuppusamy,Pitchumani, Kasi
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experimental part
p. 9090 - 9095
(2011/12/15)
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- NMR study of the tautomeric behavior of N -(α-Aminoalkyl)tetrazoles
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N-(α-Aminoalkyl)tetrazoles exist in solution as equilibrium mixtures of N1 and N2 tautomers. The position of equilibrium depends significantly on the polarity of the solvent and the substituents in the tetrazole ring. Interconversion between individual tautomers is shown to proceed via tight ion-pair intermediates in which intramolecular recombination is faster than the intermolecular crossover since the latter probably requires solvent separation of ion-pair intermediates.
- Katritzky, Alan R.,El-Gendy, Bahaa El-Dien M.,Draghici, Bogdan,Hall, C. Dennis,Steel, Peter J.
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experimental part
p. 6468 - 6476
(2010/12/24)
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- Practical synthesis of 5-substituted tetrazoles under microwave irradiation
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5-Substituted tetrazoles were prepared by treatment of nitriles with sodium azide and triethylammonium chloride in nitrobenzene in a microwave reactor. This practical method combines the advantages of previous procedures, including good-to-excellent yields, short reaction times, and easy isolation of the product. Moreover, sterically hindered tetrazoles, as well as those deactivated by electron-donating groups, can be prepared. Georg Thieme Verlag Stuttgart.
- Roh, Jaroslav,Artamonova, Tatjana V.,Vavrova, Katerina,Koldobskii, Grigorii I.,Hrabalek, Alexandr
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experimental part
p. 2175 - 2178
(2010/01/05)
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- Safe and fast tetrazole formation in ionic liquids
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The [2+3] cycloaddition of nitriles and azides is reliable for intramolecular reactions, but the hazards with volatile azides in intermolecular reactions are tremendous. Zinc catalysis in aqueous solution is a magnificent improvement, but requires the removal of the zinc salts from the acidic product. Herein, we report safe solvents featuring low vapor pressure and good solubility of NaN3. Ionic liquids based on alkylated imidazoles combined with microwave heating turned out to be a solution for the given tasks.
- Schmidt, Boris,Meid, Daniela,Kieser, Daniel
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p. 492 - 496
(2007/10/03)
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- Preparation of 5-substituted 1H-tetrazoles from nitriles in water
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The addition of sodium azide to nitriles to give 1H-tetrazoles is shown to proceed readily in water with zinc salts as catalysts. The scope of the reaction is quite broad; a variety of aromatic nitriles, activated and unactivated alkyl nitriles, substituted vinyl nitriles, thiocyanates, and cyanamides have all been shown to be viable substrates for this reaction.
- Demko, Zachary P.,Sharpless, K. Barry
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p. 7945 - 7950
(2007/10/03)
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- tris(2-Perfluorohexylethyl)tin azide: A new reagent for preparation of 5-substituted tetrazoles from nitriles with purification by fluorous/organic liquid-liquid extraction
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Summary: The synthesis of a new fluorous tin azide, (C6F13CH2CH2)3SnN3, is reported and this reagent is used to make tetrazoles in both traditional and phase-switching modes. In the traditional mode, the tin azide is reacted with nitriles followed by HCl cleavage to provide the tetrazoles and the fluorous tin chloride (which can be reconverted into the tin azide). In the switching mode, the initial tin tetrazole is purified by fluorous/organic liquid-liquid extraction prior to destannylation. This provides pure products even in incomplete reactions or with impure starting materials, but it only works for smaller nitriles.
- Curran, Dennis P.,Hadida, Sabine,Kim, Sun-Young
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p. 8997 - 9006
(2007/10/03)
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- NOVEL REAGENT FOR TETRAZOLE SYNTHESIS AND PROCESS FOR PRODUCING TETRAZOLES THEREWITH
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Analkali metal azide and zinc chloride are used in combination as a tetrazole forming agent when producing 1H-tetrazoles of the formula (II): (where R is any substituent) from carbonitriles of the formula (I): R-CN(where R has the same meaning as defined above). The tetrazole forming agent permits many kinds of solvents to be used and can in principle be used with any carbonitriles. In addition, the use of inexpensive zinc chloride leads to cost reduction.
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- Synthesis and Muscarinic Activities of Quinuclidin-3-yltriazole and -tetrazole Derivatives
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The synthesis of 15 methyl or unsubstituted 1,2,3-triazoles, 1,2,4-triazoles, and tetrazoles additionally substituted with a 1-azabicyclooctan-3-yl group is described.The potency and efficacy of these compounds as muscarinic ligands were determined in radioligand binding assays using oxotremorine and quinuclidinyl benzilate.Potency and efficacy were found in compounds in which the azole moiety was attached to the azabicyclic ring either through a carbon atom or a nitrogen atom.Electrostatic potential maps of both the C-linked and the novel N-linked series of compounds were calculated.A relationship between position and depth of the electrostatic minima relative to the azabicyclic ring and the potency and efficacy of the compounds was determined.
- Wadsworth, Harry J.,Jenkins, Sarah M.,Orlek, Barry S.,Cassidy, Frederick,Clark, Michael S. G.,et al.
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p. 1280 - 1290
(2007/10/02)
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- REACTION OF SOME DERIVATIVES OF 2-NITRO-2-AZAPROPANOL WITH AZOLES
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The reactions of the esters of 2-nitro-2-azapropanol and N-methyl-N-chloromethyl-N-nitroamine with triazoles and tetrazoles, leading to N-substituted 2-nitro-2-azapropylazoles, were studied. 1-Acyloxy-2-nitro-2-azapropanes react most readily with azoles possessing enhanced acidic characteristics.N-(2-Nitro-2-azapropyl)-1,2,3-triazole and N-(2-nitro-2-azapropyl)-1,2,4-triazole are formed during the alkylation of triazoles with methyl(chloromethyl)-N-nitroamine.
- Gareev, G. A.,Kirillova, L. P.,Shul'gina, V. M.,Buzilova, S. R.,Vologdina, L. P.,Vereshchagin, L. I.
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p. 2003 - 2007
(2007/10/02)
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- Process for the production of 5-methyltetrazole
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5-Methyltetrazole can be produced by reacting acetonitrile with an alkali azide or ammonium azide in high purity and a yield of above 98% by using a trialkyl amine as the solvent or suspension agent and by using the associated hydrochloride of the amine as the catalyst.
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- Formation of a tetrazole from (PhMe2Si)3CSiMe2I. Crystal structure of
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The iodide (Me2PhSi)3CSiMe2I was found to react with MeCN in the presence of NaN3 to give the , the structure of which was determined by an X-ray diffraction study.Some of the corresponding trimethyl-silyl-substituted tetrazole was formed from Me3SiI under similar conditions.
- Alvanipour, Abbas,Buttrus, Nabeel H.,Eaborn, Colin,Hitchcock, Peter B.,Mansour, Albdulrahman I.,Saxena, Anil K.
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- Pseudohalogeno Metal Compounds, LXV. Synthesis of Tetrazoles and Triazoles via 1,3-Dipolar Cycloaddition to the Azido Ligands of Polymeric Cobalt(III) and Palladium(II) Complexes. Synthesis and Structure of 5-Trichloromethyltetrazole
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The cycloaddition of nitriles and of dimethylacetylenedicarboxylate to the azide ligand of polymeric Schiff Base cobalt(III) and phosphine palladium(II) complexes gives the corresponding tetrazolate and triazolate complexes from which the heterocycles could be cleaved by hydrogen chloride.Usually the yields are low; if the heterocycle is soluble in ether or sublimable, yields up to 30percent have been obtained.Using this method the hitherto unknown 5-trichlormethyltetrazole could be prepared which was characterized by an X-ray structural analysis.Similarly, the cycloadditi on of azido(tetraphenylporphinato)cobalt(III) with nitriles, cyclohexylisocyanide and MeO2CCCCO2Me affords the corresponding complexes with heterocyclic ligands.The preparation of tetraphenylporphyrinato(tricyanmethanido)cobalt(III), (TPP)CoN=CC(CN)2, is reported. - Key words: Tetrazoles, Triazoles, Polymeric Schiff Base Cobalt(III) Complexes, Phosphine Palladium Complexes with Azide, Tetrazolate and Triazolate Ligands
- Geisenberger, Josef,Erbe, Juergen,Heidrich, Juergen,Nagel, Ulrich,Beck, Wolfgang
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- Thermolysis of geminal diazides: a novel route to 1,3,4-oxadiazoles
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The geminal diazides ethyl α,α-diazidoacetoacetate and α,α-diazidobenzoylacetate were prepared from the corresponding dibromo precursors by nucleophilic azide displacement.Thermolysis of the diazido compounds led to the formation of 2,5-disubstituted 1,3,4-oxadiazoles in high yield.
- Ogilvie, William,Rank, Werner
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p. 166 - 169
(2007/10/02)
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- Triazolobenzisothiazole-1,1-dioxides
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New triazolobenzisothiazole-1,1-dioxides which have the formula STR1 wherein R is hydrogen, lower alkyl, phenyl or substituted phenyl; X is hydrogen, halogen, lower alkyl, lower alkoxy or nitro; and Y is hydrogen, halogen or lower alkoxy, Are useful as anti-inflammatory agents.
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