- Regio- and Enantioselective Synthesis of Azole Hemiaminal Esters by Lewis Base Catalyzed Dynamic Kinetic Resolution
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We report a modular three-component dynamic kinetic resolution (DKR) that affords enantiomerically enriched hemiaminal esters derived from azoles and aldehydes. The novel and scalable reaction can be used to synthesize valuable substituted azoles in a regioselective manner by capping (e.g., acylation) of the equilibrating azole-aldehyde adduct. With the use of a prolinol-derived DMAP catalyst as the chiral Lewis base, the products can be obtained in high chemical yield and with high enantiomeric excess. The DKR was performed on a multikilogram scale to produce a tetrazole prodrug fragment for a leading clinical candidate that posed formidable synthesis challenges.
- Piotrowski, David W.,Kamlet, Adam S.,Dechert-Schmitt, Anne-Marie R.,Yan, Jiangli,Brandt, Thomas A.,Xiao, Jun,Wei, Liuqing,Barrila, Mark T.
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- Solid phase synthesis of biphenyltetrazole derivatives
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A dihydropyran carboxylic acid type linker is suitable for the solid phase Suzuki type aryl-aryl coupling reaction for the preparation of various biphenyltetrazole derivatives.
- Yoo, Sung-eun,Seo, Jin-soo,Yi, Kyu-yang,Gong, Young-dae
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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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- A practical synthesis of 5-(4′-methylbiphenyl-2-yl)-1H-tetrazole
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Practical synthesis of 5-(4′-methylbiphenyl-2-yl)-1H-tetrazole, key intermediate in several angiotensin II receptor antagonists from 2-fluorobenzonitrile in excellent yields and very high purity is described.
- Kantevari, Srinivas,Nair, C. K. Snehalatha,Pardhasaradhi
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- Synthesis and selective cytotoxicity of novel biphenyl-based tetrazole derivatives
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Cancer today represents a significant public health problem worldwide, and the challenge is to produce cost-effective drugs. Recently, biphenyl compounds as well as tetrazole derivatives is known for their potential nonselective anticancer activities. In search of novel selective anticancer agents, a series of newly hybrid molecules was designed and synthesized by combining the structural features of biphenyl and tetrazole moieties. The structures of newly synthesized compounds were characterized using spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, and HMBC). Cytotoxic evaluations of these novels compound on human cancer cell lines showed a significant anticancer activity against more than one tested cell lines. Compounds 5n, 5j, and 5o proved to exhibit the strongest and selective cytotoxic effect on HepG2 and MCF-7 lines. Taken together, this study has led to the development of promising leads for cancer therapy.
- Malani, Mahesh H.,Dholakiya, Bharatkumar Z.,Ibrahim, Ahmed S.,Badria, Farid A.
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- Synthesis of 5-substituted lH-tetrazoles from nitriles and hydrazoic acid by using a safe and scalable high-temperature microreactor approach
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Harnessing hydrazoic acid in a microreactor! Tetrazoles have been synthesized in a very efficient manner by using a high-temperature/high-pressure process intensification regime. Despite the toxic and explosive nature of hydrazoic acid, the synthesis was conducted safely in continuous flow format with residence times as short as 2.5 minutes at 260□°C (see picture).
- Gutmann, Bernhard,Roduit, Jean-Paul,Kappe, C. Oliver,Roberge, Dominique
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- Urea mediated 5-substituted-1H-tetrazole via [3?+?2] cycloaddition of nitriles and sodium azide
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A simple, new and convenient metal free procedure for the synthesis of 5-substituted 1H-tetrazoles using various nitriles and sodium azide in the presence of urea and acetic acid with good to high yields is developed. The reaction plausibly proceeds through in situ formation of urea azide active complex without toxic and/or expensive metal catalysts.
- Yakambram,Jaya Shree,Srinivasula Reddy,Satyanarayana,Naveen,Bandichhor, Rakeshwar
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- Synthesis and characterization of 4′-bromomethyl-2-(N-trityl-1H- tetrazol-5-yl) biphenyl
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Biphenyl tetrazole ring is an important component of the Sartan family of novel drugs. 4′-Bromomethyl-2-(N-trityl-1H-tetrazol-5-yl)biphenyl was synthesized in this article from 4′-methyl-2-cyano-biphenyl through three steps. 4′-Methyl-2-cyano-biphenyl was reacted with azide ions with the help of ammonium chloride as catalyst in an autoclave with high conversion to afford the tetrazole compounds in 70.6% yield. After being protected by the trityl group with 92.6% yield, 4′-methyl-2-(N-trityl-1H-tetrazol-5-yl) biphenyl was brominated with N-bromosuccinimide (NBS) in cyclohexane with 2,2′-azo-isobutyronitrile (AIBN) acting as an initiator to provide the title compound in 83.8% yield. Copyright Taylor & Francis Group, LLC.
- Wang, Guo-Xi,Sun, Bao-Ping,Ru, Zong-Ling
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- Zn/MeOH-Mediated Practical and Easy Detritylation of Protected 1-Trityltetrazoles
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A practical and low-cost method for the detritylation of 1-titryltetrazoles using zinc and methanol is described. This procedure is versatile and efficient in the deprotection of several protected tetrazoles bearing aliphatic, aromatic, and heteroaromatic substituents, as well as some functional groups, without decomposition of the tetrazole ring.
- Behloul, Cherif,Bouchelouche, Kenza,Hadji, Yasmine,Benseghir, Saadia,Guijarro, David,Nájera, Carmen,Yus, Miguel
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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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- A novel method for the synthesis of 5-substituted 1H-tetrazole from oxime and sodium azide
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A simple and efficient protocol is developed for the synthesis of 5-substituted 1H-tetrazoles from various oximes and sodium azide (NaN 3) by using copper acetate as a catalyst.
- Patil, Umakant B.,Kumthekar, Kedar R.,Nagarkar, Jayashree M.
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- Bacterial Peptide Deformylase Inhibition of Tetrazole-Substituted Biaryl Acid Analogs: Synthesis, Biological Evaluations, and Molecular Docking Study
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The synthesis and screening of tetrazole-substituted biaryl acid analogs 7a–l as bacterial peptide deformylase (PDF) enzyme inhibitors is reported. The compounds 7e (IC50 value = 5.50 μM) and 7g (IC50 value = 7.25 μM) showed good PDF inhibition activity. The compounds 7e (MIC range = 10.75–11.66 μg/mL) and 7g (MIC range = 8.91–12.83 μg/mL) also showed potent antibacterial activity when compared with the standard ciprofloxacin (MIC range = 25–50 μg/mL). Thus, the active derivatives were not only potent PDF enzyme inhibitors but also efficient antibacterial agents. In order to gain more insight into the binding mode of the compounds with the PDF enzyme, the most active compounds 7e and 7g, the moderately active compound 7k, and the least active compound 7h were docked against the PDF enzyme of Escherichia coli. The docking study of the most active compounds 7e and 7g against the PDF enzyme exhibited good binding properties. Hence, we believe our synthesized compounds 7a–l could serve as reservoir for bacterial PDF inhibitor development.
- Khan, Firoz A. Kalam,Patil, Rajendra H.,Patil, Manjiri,Arote, Rohidas,Shinde, Devanand B.,Sangshetti, Jaiprakash N.
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- Preparation of 5-substituted 1H-tetrazoles catalyzed by scandium triflate in water
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Several 5-substituted 1H-tetrazoles were prepared in water or isopropanol/water mixtures using microwave heating. Good yields were obtained for the [2 + 3] cycloaddition of sodium azide with aryl nitriles, aliphatic nitriles, and vinyl nitriles when catal
- Coca, Adiel,Turek, Evan,Feinn, Liana
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- Novel synthesis of 5-substituted tetrazoles from nitriles
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A variety of 5-substituted tetrazoles were prepared through the respective reactions of sodium azide with corresponding nitriles in an aromatic solvent in the presence of an amine salt.
- Koguro, Kiyoto,Oga, Toshikazu,Mitsui, Sunao,Orita, Ryozo
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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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- Copper-catalyzed synthesis of 5-substituted 1H-tetrazoles via the [3+2] cycloaddition of nitriles and trimethylsilyl azide
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The [3+2] cycloaddition between various nitriles and trimethylsilyl azide proceeds smoothly in the presence of a CuI catalyst in DMF/MeOH, to give the corresponding 5-substituted 1H-tetrazoles in good to high yields. The reaction most probably proceeds through the in situ formation of a copper azide species, followed by a successive [3+2] cycloaddition with the nitriles.
- Jin, Tienan,Kitahara, Fukuzou,Kamijo, Shin,Yamamoto, Yoshinori
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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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- Phosphomolybdic acid (H3Mo12O40P) as a reusable heterogeneous catalyst for the synthesis of 5-substituted 1 H-Tetrazoles via [2+3] cycloaddition of nitriles and sodium azide
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An efficient and practical protocol for the preparation of 5-substituted 1H-tetrazole derivatives is reported using phosphomolybdic acid as an effective heterogeneous catalyst. Good yields, simple methodology, and easy workup make this protocol more attractive for the diversity-oriented synthesis of these heterocycle libraries. The catalyst can be recycled three times with good yields.
- Takale, Santosh,Manave, Smita,Phatangare, Kiran,Padalkar, Vikas,Darvatkar, Nitin,Chaskar, Atul
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- TBAF-Catalyzed Synthesis of 5-Substituted 1H-Tetrazoles under Solventless Conditions
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Tetrabutylammonium fluoride (TBAF) is an efficient catalyst in the [3 + 2] cycloaddition reaction of organic nitriles 1 with trimethylsilyl azide (TMSN3) in solventless conditions. The corresponding 5-substituted 1H-tetrazoles 2 were obtained under mild conditions and in 80-97% yields.
- Amantini, David,Beleggia, Romina,Fringuelli, Francesco,Pizzo, Ferdinando,Vaccaro, Luigi
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- Method for synthesizing high-purity sartan side chain TTBB
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The invention discloses a method for synthesizing high-purity sartan side chain TTBB. The method comprises the following steps: taking 4-methyl-2-cyanobiphenyl as a starting material; under a catalytic action of lewis acid triethylamine hydrochloride, carrying out cyclization reaction on the 4-methyl-2-cyanobiphenyl and sodium azide to generate a 5-[2-(4'-methyldiphenyl)]tetrazole compound; reacting the 5-[2-(4'-methyldiphenyl)] tetrazole compound with triphenylchloromethane under an alkaline condition to generate an N-(triphenylmethyl)-5-(4'-methylbiphenyl-2-yl)tetrazole compound; reacting togenerate a mixture of a compound TTBB and a compound Br-TTBB under the action of bromine-containing substances; promoting the compound Br-TTBB to be converted into the compound TTBB under the actionof diethyl phosphite by the mixture, thus finally obtaining the high-purity sartan side chain TTBB. The synthetic process disclosed by the invention has the advantages of better economical property, environment friendliness, high efficiency, simplicity and convenience; the mode of improving the purity of a target product through recrystallization for multiple times by adopting a conventional method is avoided.
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Paragraph 0020-0039
(2018/06/15)
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- Antimicrobial evaluation of 5-substituted aryl 1H-tetrazoles
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Background: Tetrazole derivatives such as 1-substituted dinitrobenzyl tetrazoles and their oxa and selanyl analogs have previously been studied against drug-susceptible and multidrugresistant mycobacteria. In addition, other tetrazole derivatives have bee
- Feinn, Liana,Dudley, Joshua,Coca, Adiel,Roberts, Elizabeth L.
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p. 359 - 364
(2017/06/20)
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- 5 - (4 '- methyl - [1, 1' - biphenyl] - 2 - yl) - 1 - tetrazole synthesis method of hydrogen
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The invention discloses a synthesis method of 5-(4'-methyl-[1,1'-biphenyl]-2-yl)-1-hydro-tetrazole, which comprises the following steps: by using 2-carboxy-4'-methyl biphenyl as the raw material, reacting with excessive thionyl chloride under reflux conditions, depressurizing to remove excess thionyl chloride, and carrying out acylation reaction on benzsulfamide to obtain a product III; reacting the product III with phosphorous pentachloride by using carbon tetrachloride as a solvent to obtain an imino acyl chloride derivative IV; carrying out substitution reaction on the imino acyl chloride derivative IV and hydrazine hydrate to obtain a product V; and finally, carrying out cyclization on the product V and sodium nitrate under acidic conditions, and carrying out benzenesulfonyl removal reaction to obtain the 5-(4'-methyl-[1,1'-biphenyl]-2-yl)-1-hydro-tetrazole. The method has the advantages of mild reaction conditions, high safety and high efficiency.
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Paragraph 0023; 0024; 0025; 0026
(2017/08/25)
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- 1,(3,)5-substituted imidazoles, useful in the treatment of hypertension and methods for their preparation
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The present invention provides novel 1,5 and 1,3,5-substituted imidazole compounds in hydrophilic or lipophilic form, which are useful as angiotensin II ATI receptor antagonists suitable for transdermal delivery. The invention also provides pharmaceutical compositions containing such compounds, processes and intermediates for preparing compounds and their use in methods of treating hypertension and cardiovascular diseases.
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- 2 - (1-dihydro-4-tetrazole) - 4 the synthesis of-methyl diphenyl [...] method
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The invention discloses a synthetic method of 2-(1-hydro-4-tetrazole)-4'-methyl diphenyl. The method comprises the following steps: by taking 2-carboxyl-4'-methyl diphenyl as a raw material, reacting with benzene sulfonamide under a high-temperature melting condition; subsequently adding ammonium acetate and reacting again at the high-temperature melting condition to prepare 2-amidino-4'-methyl diphenyl; afterwards allowing 2-amidino-4'-methyl diphenyl and hydrazine hydrate to have a substitution reaction to prepare 4'-methyl-[1,1'-diphenyl]-2-formamide hydrazide; finally allowing 4'-methyl-[1,1'-diphenyl]-2-formamide hydrazide and sodium nitrite to have a cyclization reaction to prepare 2-(1-hydro-4-tetrazole)-4'-methyl diphenyl. The synthetic method disclosed by the invention is mild in reaction condition, simple and convenient to operate and suitable for industrial production; carboxylic acid is creatively used for replacing nitrile as a raw material; the use of a highly-toxic and easily-explosive reagent is avoided, such as a reagent like sodium azide; the raw materials are easy to obtain and safe; convenience is provided for production management; the cost is relatively low; pollution of three wastes is reduced.
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Paragraph 0019; 0020
(2017/03/08)
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- Indium-Mediated Cleavage of the Trityl Group from Protected 1 H -Tetrazoles
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On treatment with indium metal in MeOH-THF, trityl groups undergo reductive removal from 1H-protected tetrazoles (including aliphatic, aromatic, and heteroaromatic substituents), affording the corresponding free tetrazoles in excellent yields, without any decomposition of the tetrazole ring or reduction of any other group.
- Behloul, Cherif,Bouchelouche, Kenza,Guijarro, David,Foubelo, Francisco,Nájera, Carmen,Yus, Miguel
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supporting information
p. 2399 - 2402
(2015/10/19)
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- DEPROTECTION METHOD FOR TETRAZOLE COMPOUND
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The present invention relates to a method of deprotecting a tetrazole compound, useful as an intermediate for angiotensin II receptor blockers, and provides a novel production method of angiotensin II receptor blockers. Provided is a production method of a compound represented by the formula [3] or [4] or a salt thereof, including (i) reducing a compound represented by the formula [1] or [2] or a salt thereof in the presence of a metal catalyst and an alkaline earth metal salt, or (ii) reacting the compound with a particular amount of Br?nsted acid: wherein each symbol is as defined in the present specification.
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(2015/09/23)
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- Synthesis of new biphenyl-substituted quinoline derivatives, preliminary screening and docking studies
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New quinoline derivatives containing biphenyl ring were synthesized and characterized by IR, 1H NMR and mass spectral studies. The synthesized compounds were screened for antimicrobial, anthelmintic activities as well as free radical scavenging property against the DPPH radical. The minimum inhibition concentration values showed promising inhibiting activity and are potent biological agents. The compounds showed minimum binding energy towards ?-tubulin. The compounds 11a, 11c, 13c and 13d have good affinity towards the active pocket and may be considered as a good inhibitor of β-tubulin. Indian Academy of Sciences.
- Shashikumar, Nellisara D.,Krishnamurthy, Ganganaika,Bhojyanaik, Halehatti S.,Lokesh, Mayasandra R.,Jithendrakumara, Kaginalli S.
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p. 205 - 212
(2014/04/03)
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- Synthesis of new biphenyl-substituted quinoline derivatives, preliminary screening and docking studies
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New quinoline derivatives containing biphenyl ring were synthesized and characterized by IR, 1H NMR and mass spectral studies. The synthesized compounds were screened for antimicrobial, anthelmintic activities as well as free radical scavenging property against the DPPH radical. The minimum inhibition concentration values showed promising inhibiting activity and are potent biological agents. The compounds showed minimum binding energy towards β-tubulin. The compounds 11a, 11c, 13c and 13d have good affinity towards the active pocket and may be considered as a good inhibitor of β-tubulin.
- Shashikumar, Nellisara D,Krishnamurthy, Ganganaika,BhojyaNaik, Halehatti S,Lokesh, Mayasandra R,Jithendrakumara, Kaginalli S
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p. 205 - 212
(2016/03/01)
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- N-ARYLYLMETHYLINDAZOLE MODULATORS OF PPARG
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The invention provides molecular entities that bind with high affinity to PPARG (PPARy), inhibit cdJk5-mediated phosphorylation of PP ARG, but do not exert an agonistic effect on PPARG. Compounds of the invention can be used for treatment of conditions in patients wherein PPARG plays a role, such as diabetes or obesity. Methods of preparation of the compounds, bioassay methods for evaluating compounds of the invention as non-agonistic PPARG binding compounds, and pharmaceutical compositions are also provided.
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- Synthesis of heteroaromatic derivatives with nitrogen atoms: Tripyrrolyl pyrimidine and tripyrrolyl[1,3,5]triazine
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As a part of a research program related to the synthetic study of pharmacologically and photoconductively interesting pyrrole derivatives, we have synthesized 1-arylpyrroles (3a-e), 9-arylcarbazoles (4a-e), aminophenylpyrroles (6a,b), dipyrrolylbenzenes (7a-c), 2,4,6-tri-pyrrol-1- yl-pyrimidine (8) and 2,4,6-tri-pyrrol-1-yl[1,3,5]triazine (9). We proposed a plausible mechanism for the formation of 9-arylcarbazole.
- Lee,Lee,Jung,Hahn
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p. 501 - 504
(2013/02/22)
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- Green synthetic approach to 5-substituted-1h-tetrazoles via recycle and reuse of tributyltin chloride
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A simple, safe and efficient process for the recycle of tributyltin chloride from tributyltin hydroxide is developed and its reuse in the synthesis of 5-substituted-1H-tetrazoles is successfully demonstrated, which paved a way to reduce the toxic tin waste significantly. Recycling of tributyltin chloride is possible over six cycles without loss of its activity.
- Sampath,Reddy, V. Prabhakar,Chakravarthy, A. Kalyan,Reddy, P. Pratap
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p. 393 - 396
(2013/02/22)
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- NOVEL ZINC AZIDE COMPLEX AND A PROCESS FOR PREPARING TETRAZOLE DERIVATIVES USING THE SAME
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The present invention relates to a novel zinc azide complex. The present invention also relates to a process for preparing 5-substituted-1H-tetrazole derivatives from nitrile derivatives by using the zinc azide complex. According to the present invention, in particular, pharmaceutically active compounds for treating hypertension or intermediates useful for preparation thereof can be prepared effectively.
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(2012/11/13)
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- The discovery of new potent non-peptide Angiotensin II AT1 receptor blockers: A concise synthesis, molecular docking studies and biological evaluation of N-substituted 5-butylimidazole derivatives
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A convenient and facile synthesis, in silico docking studies and in vitro biological evaluation of N-substituted 5-butylimidazole derivatives as potent Angiotensin II (ANG II) receptor type 1 (AT1) blockers (ARBs) has been reported in the current study. Our efforts have been directed towards the development of an efficient synthetic route allowing the facile introduction of substituents on the imidazole ring. In particular, a series of imidazole based compounds bearing the biphenyl moiety at the N - 1 position, a halogen atom at the C-4 and polar substituents such as hydroxymethyl, aldo or carboxy group at the C-2 position were designed and synthesized. These compounds were evaluated for binding to human AT1 receptor and for ANG II antagonism in vitro on isolated rat uterus. Among them, 5-butyl-1-[[2′-(2H-tetrazol-5-yl)biphenyl-4-yl] methyl]imidazole-2-carboxylic acid (30) exhibited higher binding affinity compared to the other analogues tested (-log IC50 = 8.46). The latter analogue was also found to be the most active in the rat uterotonic test (pA2 = 7.83). Importantly, the binding affinity was higher to that of losartan (-log IC50 = 8.25) indicating the importance of carboxy group at the C-2 position. Experimental findings are in good agreement with docking studies, which were undertaken in order to investigate ligand/AT1 receptor interactions.
- Agelis, George,Resvani, Amalia,Matsoukas, John,Durdagi, Serdar,Spyridaki, Katerina,Liapakis, George,Tumova, Tereza,Slaninova, Jirina,Giannopoulos, Panagiotis,Mavromoustakos, Thomas,Vlahakos, Demetrios
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p. 358 - 374,17
(2020/07/30)
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- An efficient synthesis, X-ray and spectral characterization of biphenyl derivatives
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Derivatives of 1,3-thiazolidin-2,4-dione appended to biphenyl ring viz., 7-9, 16-18 were prepared. The newly synthesized compounds were confirmed by IR, NMR (1H and 13(C) MS and elemental analyses. Single crystal X-ray diffraction study was carried out for one of the final compounds 9. Indian Academy of Sciences.
- Kamble, Ravindra R.,Biradar, Dharesh B.,Meti, Gangadhar Y.,Taj, Tasneem,Gireesh, Tegginamath,Khazi, Imthiyaz Ahmed M.,Vaidyanathan, Sundar T.,Mohandoss, Raju,Sridhar, Balasubramanian,Parthasarathi, Viraraghav
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experimental part
p. 393 - 401
(2012/04/04)
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- Highly efficient synthesis of 5-substituted 1H-tetrazoles catalyzed by Cu-Zn alloy nanopowder, conversion into 1,5- and 2,5-disubstituted tetrazoles, and synthesis and NMR studies of new tetrazolium ionic liquids
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A series of 5-substituted 1H-tetrazoles were synthesized through [3+2] cycloaddition reactions between nitriles RCN and NaN3 in the presence of Cu-Zn alloy nanopowder as catalyst. The 1,5-dibutyl, 1-butyl-5-hexyl, 2,5-dibutyl, and 2-butyl-5-hexyl derivatives were then used as building blocks to synthesize several novel tetrazolium ionic liquids (ILs) with EtSO 4-, OTf-, and NTf2- counterions. Whereas alkylation of the 2,5-dialkyltetrazoles selectively gave the N-4 alkylated onium salts, with the 1,5-dialkyl derivatives approximately 1:1 mixtures of two tetrazolium salts were formed by alkylation at N-3 and N-4. The triflate and ethyl sulfate salts are room-temperature ILs that are hydrophilic, whereas the NTf2 salts are low-melting ILs and are hydrophobic. The resulting tetrazolium-based ionic liquids were studied by various multinuclear and 2D NMR techniques including natural abundance 15N and 1H/15N correlations.
- Aridoss, Gopalakrishnan,Laali, Kenneth K.
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experimental part
p. 6343 - 6355
(2011/12/03)
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- A simple, advantageous synthesis of 5-substituted 1 h -tetrazoles
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An advantageous synthesis of 5-substituted 1H-tetrazoles has been developed by treatment of organic nitriles with NaN3 in the presence of iodine or the heterogeneous catalyst, silica-supported sodium hydrogen sulfate (NaHSO4SiO2). Georg Thieme Verlag Stuttgart New York.
- Das, Biswanath,Reddy, Cheruku Ravindra,Kumar, Duddukuri Nandan,Krishnaiah, Martha,Narender, Ravirala
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experimental part
p. 391 - 394
(2010/04/24)
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- Original loading and Suzuki conditions for the solid-phase synthesis of biphenyltetrazoles. Application to the first solid-phase synthesis of irbesartan
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Biphenyltetrazoles are recognized privileged structures. Among them, the therapeutically important class of sartans displays antagonistic activity on AT1 receptors. We have developed a method for anchoring tetrazole derivatives via the heterocycle on a hydroxylated resin using zinc triflate. New Suzuki-Miyaura cross-coupling conditions are developed for the quantitative formation of the phenyl-phenyl bond. Our straightforward synthesis scheme, starting from the conserved phenyltetrazole moiety and ending with the appending of the structurally variable moiety, is well suited to the preparation of sartans and their analogues at a laboratory scale. We thus describe here the first solid phase synthesis of irbesartan, a marketed AT1 antagonist.
- Cousaert, Nicolas,Willand, Nicolas,Gesquière, Jean-Claude,Tartar, André,Déprez, Beno?t,Deprez-Poulain, Rebecca
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p. 2743 - 2747
(2008/09/18)
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- PROCESS FOR THE PREPARATION OF VALSARTAN
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The present invention relates to a process for preparing valsartan from a compound of general formula (I), wherein R is cumyl, trityl or t-butyl. The process comprises a first step, wherein the protective group is eliminated and thereafter the oxazolidinone ring is opened by catalytic hydrogenationin the presence of an organic base. Finally, Valsartanor a pharmaceutically acceptable salt thereofis isolated.
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Page/Page column 9; 13
(2009/01/20)
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- Synthesis of novel biphenyltetrazole derivatives containing 5-methylisoxazole substituted 1,2,4-triazole
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An efficient route to synthesize the target compounds was developed. Fifteen new 5-[4′-(5-isoxazol-4-aryl-1,2,4-triazol-3-yl-sulfanylmethyl)- biphenyl-2-yl]-tetrazoles derivatives were synthesized. The structures of the new compounds synthesized were confirmed by elemental analyses and spectral data.
- Sun, De-Guang,Hui, Xin-Ping,Xu, Peng-Fei,Zhang, Zi-Yi,Guan, Zuo-Wu
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p. 795 - 801
(2008/02/12)
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- Synthesis and antibacterial activities of novel biphenyltetrazole derivatives bearing 1,3,4-oxadiazole
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Several new 5-[4 -(5-phenyl-1,3,4-oxadiazol-2-ylsulfanylmethyl)-biphenyl-2- yl]-tetrazolesderivatives have been syn the sized. The structures of these new compounds were confirmed by elementary analyses and spectral data. The antibacterial activities of the compounds were also evaluated.
- Chao, Shu-Jun,Hui, Xin-Ping,Li, Shuo,Qiu, Zao-Zao,Xu, Peng-Fei,Zhang, Zi-Yi,Wang, Qin,Guan, Zuo-Wu
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p. 539 - 544
(2007/10/03)
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- PROCESS FOR THE PREPARATION OF TETRAZOLE DERIVATIVES FROM ORGANO BORON AND ORGANO ALUMINIUM AZIDES
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The present invention relates to a method for preparing substituted tetrazoles, compounds obtained according to this method, new reactants and new tetrazole derivatives.
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Page/Page column 41
(2008/06/13)
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- Kinetics of decomposition of irbesartan in aqueous solutions determined by high performance liquid chromatography
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The kinetics of breakdown of irbesartan in aqueous solutions at elevated temperatures has been investigated by a high performance liquid chromatography method. The reaction is found to follow first-order kinetics and the rate constant for the degradation at 25 °C is estimated by extrapolation. The decomposition of irbesartan is shown to be hydroxide ion catalysed and the effects of ionic strength and buffer concentrations to such rate studies are discussed.
- Mbah
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p. 920 - 922
(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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- Production process and intermediate of tetrazole compound
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There are disclosed an industrially favorable process for producing a tetrazole compound of general formula (1): STR1 characterized in that a nitrile of general formula (2): is reacted with hydrazine or a salt thereof in the presence of a catalyst, followed by reaction with a nitrous acid compound of general formula (3): or a nitrile of general formula (2) is reacted with hydrogen sulfide, followed by reaction with an alkyl halide of general formula (4): with hydrazine or a salt thereof, and then with a nitrous acid compound of general formula (3); and an intermediate of general formula (5): which is useful for the production of the tetrazole compound (in which R1 to R6, A and J in the above formulas are as defined in the specification).
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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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- Process for preparation of 5- substituted tetrazoles
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The invention is directed to a process for preparing a 5-substituted tetrazole, the process comprising the step of reacting a nitrile with an inorganic azide salt in an aromatic hydrocarbon solvent in the presence of an amine salt. According to the invention, a 5-substituted tetrazole can be produced in a high yield with ease and safety using inexpensive raw materials while the reaction is easily controlled to inhibit a side reaction.
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- Method of synthesizing sterically hindered 5-substituted-1H-tetrazoles from nitriles using a lewis acid and an azide
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A method for making 5-substituted tetrazoles of formula I: STR1 where R is as herein described which comprises reacting a compound of the formula R--CN with a Lewis acid and an azide or a preformed metal azide complex, acidifying and recovering the 5-subs
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- Process for the preparation of tetrazoles
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The present invention relates to a process for the preparation of 5-aryl tetrazoles of the formula: STR1 or a salt thereof comprising reacting an aryl nitrile with a trisubstituted silyl azide and a disubstituted tin oxide.
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- Process for the preparation of certain substituted biphenyl tetrazoles and compounds thereof
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A process for producing a compound of formula I: STR1 comprising reacting 5-(2-fluorophenyl)-1H-tetrazole with a Grignard reagent to produce the desired product is disclosed. Novel compounds produced by this process for use as intermediates in making cert
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