- 5-(Benzylmercapto)-1H-tetrazole as activator for 2′-O-TBDMS phosphoramidite building blocks in RNA synthesis
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An improved method for the preparation of 5-(benzylmercapto)-1H-tetrazol as activator in RNA synthesis is described. Reaction of benzylthiocyanate with azide delivers the corresponding tetrazole with 72% yield under optimised conditions. We demonstrate that 5-(benzylmercapto)-1H-tetrazol is a superior activator of 2′-O-TBDMS phosphoramidite building blocks. Compared to routinely used 1H-tetrazol, application of a 0.25 M 5-(benzylmercapto)-1H-tetrazol solution in acetonitrile allows for higher coupling yields (>99%), lower coupling times (3 min) and reduced excess of phosphoramidites in solution over the solid-phase nucleotides (8-fold).
- Welz, Rüdiger,Müller, Sabine
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- Synthesis, characterization and theoretical studies of 5-(benzylthio)-1- cylopentyl-1H-tetrazole
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In this study, 5-(benzylthio)-1-cylopentyl-1H-tetrazole (5B1C1HT) have been synthesized. Boiling points of the obtained compound have been determined and it has been characterized by FT-IR, 1H NMR, 13C-APT and LC-MS spectroscopy techniques. The FT-IR, 1H NMR and 13C-APT spectral measurements of the 5B1C1HT compound and complete assignment of the vibrational bands observed in spectra has been discussed. The spectra were interpreted with the aid of normal coordinate analysis following full structure optimization and force field calculations based on Density Functional Theory (DFT) at 6-311++G**, cc-pVDZ and cc-pVTZ basis sets. The optimized geometry with 6-311++G ** basis sets were used to determine the total energy distribution, harmonic vibrational frequencies, IR intensities.
- Saglam,Disli,Erdogdu,Marchewka,Kanagathara,Bay,Güllüo?lu
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- L -Proline: An Efficient Organocatalyst for the Synthesis of 5-Substituted 1 H -Tetrazoles via [3+2] Cycloaddition of Nitriles and Sodium Azide
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A simple and efficient route for the synthesis of a series of 5-substituted 1 H -tetrazoles using l -proline as a catalyst from structurally diverse organic nitriles and sodium azide is reported. The prominent features of this environmentally benign, cost effective, and high-yielding l -proline-catalyzed protocol includes simple experimental procedure, short reaction time, simple workup, and excellent yields making it a safer and economical alternative to hazardous Lewis acid catalyzed methods. The protocol was successfully applied to a broad range of substrates, including aliphatic and aryl nitriles, organic thiocyanates, and cyanamides.
- Bhagat, Saket B.,Telvekar, Vikas N.
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supporting information
p. 874 - 879
(2018/02/16)
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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 0100-0108
(2018/09/08)
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- Synthesis and antibacterial evaluation of new sulfanyltetrazole derivatives bearing piperidine dithiocarbamate moiety
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A series of new alkyl or aryl sulfanyltetrazole derivatives containing dithiocarbamate moiety (5a–6e) were synthesized. The structures of the compounds were characterized by IR, 1H NMR, 13C NMR spectra, and elemental analysis data. The present study examines the antibacterial potential of novel synthetic sulfanyltetrazole compounds against clinically important gram-positive and -negative strains. The results of screening showed that attachment of dithiocarbamate to sulfanyltetrazole derivatives results in enhancement of antibacterial activity. The compound 6d showed the best activity among the tested compounds. Also, the less polar 2,5-disubstituted sulfanyltetrazole regioisomers showed an increased antibacterial activity compared with the corresponding more polar regioisomers.
- Baghershiroudi, Mahrokh,Safa, Kazem D.,Adibkia, Khosro,Lotfipour, Farzaneh
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p. 323 - 328
(2018/02/09)
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- Antibacterial assessment of heteroaryl, Vinyl, Benzyl, and Alkyl tetrazole compounds
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Background: In previous reports, the antibacterial properties of certain tetrazole derivatives have been described. We have previously reported the antibacterial properties of aryl 1H-tetrazole compounds. Objective: To study the antibacterial activity of 5-substituted heteroaryl, vinyl, benzyl, and alkyl 1H-tetrazole derivatives. Methods: The antibacterial properties of heteroaryl, vinyl, benzylic, and aliphatic tetrazole derivatives were investigated against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The activity was assessed by determining the minimum inhibitory concentration of these tetrazole derivatives and comparing them to the known antibiotics amoxicillin, trimethoprim and sulfamethoxazole. Results: The tetrazole compounds were prepared utilizing cerium(III) chloride heptahydrate catalysis at 160o C for 1-4 h in a microwave reactor using an aqueous solvent mixture. The most active derivatives exhibited minimum inhibitory concentration values between 125-250 μg/mL against Escherichia coli. More importantly, these compounds were considerably more active when used in combination with trimethoprim and a significant synergistic effect was observed (MIC = 0.98-7.81 μg/mL) against E. coli and S. aureus. Conclusion: The tetrazole derivatives were synthesized in high yield and short reaction times in water. Several of the tetrazole compounds showed a significant synergistic antibacterial effect when used with trimethoprim.
- Dudley, Joshua,Feinn, Liana,Defrancesco, Heather,Lindsay, Erica,Coca, Adiel,Roberts, Elizabeth Lewis
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p. 550 - 555
(2018/08/17)
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- Bulky organosilicon compounds based on sulfanyltetrazoles: their synthesis and in vitro antibacterial evaluation
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The study introduces different organosilicon derivatives incorporating sulfanyltetrazole ring for biological applications. Initially, the sulfanyltetrazole derivatives and halo-analogues (Br, I) were synthesized. Later, selective reaction of tris(trimethylsilyl)methyllithium (TsiLi) in the presence (?46 and 0?°C) and absence (room temperature) of CS2 with halo-sulfanyltetrazole derivatives yielded new multifunctional sulfanyltetrazole regioisomers with SH, C?=?S, ethynylthio and SiMe3 groups, respectively. All the synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR spectra and elemental analysis data. The compounds were screened for their antibacterial activities against clinically important gram-positive and gram-negative bacteria using the spectrophotometric microdilution method. The preliminary screening indicated that the organosilicon derivatives incorporating SH and C?=?S (mercapto-silyl-thiones) and silyl-thioalkynes have antibacterial activities, whereas no antibacterial activity was observed on compounds containing (Me3Si)3C groups. Of the synthesized compounds, compound 5d showed the best activity against all the tested organisms (3.91–31.25?μg/mL).
- Baghershiroudi, Mahrokh,Safa, Kazem D.,Adibkia, Khosro,Lotfipour, Farzaneh
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p. 1279 - 1286
(2018/05/22)
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- Mechanism of the zinc-catalyzed addition of azide ion to unsaturated compounds: Synthesis of 5-substituted 1Н-tetrazoles from nitriles and of 1-substituted 1Н-tetrazole-5-thiols from isothiocyanates
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The mechanism of the formation of 5-substituted 1H-tetrazoles from organic nitriles and thiocyanates in the presence of NaN3 and ZnCl2 in aliphatic alcohols was studied. The results of this study allowed efficient methods of synthesis of substituted tetrazoles from nitriles, thiocyanates, and isothiocyanates to be proposed.
- Myznikov,Vorona,Artamonova,Zevatskii, Yu. E.
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p. 731 - 738
(2017/05/29)
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- One-pot synthesis of 5-alkylsulfanyl-1H-tetrazoles from alkyl halides
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An efficient one-pot method for the synthesis of 5-alkylsulfanyl-1H-tetrazoles, tetrazol-5-ylmethane- and -ethanethiol derivatives was developed.
- Myznikov,Vorona,Artamonova,Zevatskii, Yu. E.
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p. 1313 - 1316
(2017/08/08)
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- Tetrazole regioisomers in the development of nitro group-containing antitubercular agents
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Tetrazole derivatives containing nitro substituents have been identified as promising antitubercular agents. In this study, the antitubercular potency, selectivity and toxicity of tetrazole 1,5- and 2,5-regioisomers were examined. We prepared a series of 1- and 2-alkyl-5-benzylsulfanyl-2H-tetrazoles and their selenium analogs with various nitro group substitutions. These 1,5- and 2,5-regioisomers were isolated and unambiguously identified using 1H and/or 13C NMR. Among the prepared compounds, 1- and 2-alkyl-5-[(3,5-dinitrobenzyl)sulfanyl]-2H-tetrazole derivatives and their selenium bioisosteres showed the highest antimycobacterial activity, with minimal inhibitory concentration (MIC) values of approximately 1 μM (0.37-0.46 μg mL-1) against Mycobacterium tuberculosis CNCTC My 331/88. The 2-alkyl regioisomers exhibited consistently higher antimycobacterial activity and lower in vitro toxicity against a mammalian cell line compared to the 1-alkyl isomers. The antimycobacterial activity of the 2-alkyl regioisomers was less influenced by the type of alkyl substituent in contrast to 1-alkyl isomers. Furthermore, the 3,5-dinitrobenzyl moiety per se is not the carrier of mutagenicity. These findings encourage further optimization of the 2-alkyl chain to improve the pharmacokinetic properties and toxicity of 2-alkyl-5-[(3,5-dinitrobenzyl)sulfanyl]-2H-tetrazole lead compounds. This journal is
- Karabanovich, Galina,Roh, Jaroslav,Soukup, Ondej,Pvkov, Ivona,Pasdiorov, Markta,Tambor, Vojtch,Stolakov, Jiina,Vejsov, Marcela,Vvrov, Kateina,Klimeov, Vra,Hrablek, Alexandr
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supporting information
p. 174 - 181
(2015/02/02)
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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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- Synthesis of thiotetrazoles and arylaminotetrazoles using rutile TiO 2 nanoparticles as a heterogeneous and reusable catalyst
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A novel method is described to prepare rutile TiO2 nanoparticles which are reusable and efficient heterogeneous catalysts for the synthesis of thiotetrazoles and arylaminotetrazoles - compounds widely used in medicinal and coordination chemistry. This procedure has the advantages of good to excellent yields of products, elimination of homogeneous catalysts and toxic and explosive reagents, simple methodology, easy work up and the reusability of the heterogeneous catalyst.
- Maham, Mehdi,Khalaj, Mehdi
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p. 502 - 506
(2014/11/08)
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- 1,3-Dipolar cycloaddition: Click chemistry for the synthesis of 5-substituted tetrazoles from organoaluminum azides and nitriles
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Cheap and safe: Conventional methods to prepare tetrazoles employ dangerous, toxic reagents. A new route to these heterocycles (see scheme) uses inexpensive and nontoxic dialkyl aluminum azides. The cycloaddition occurs under mild conditions and tolerates a variety of functional groups. The low cost and ecocompatibility make this process attractive for large-scale preparation. (Chemical Equation Presented).
- Aureggi, Valentina,Sedelmeier, Gottfried
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p. 8440 - 8444
(2008/09/19)
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- Preparation of 5-alkylthio and 5-arylthiotetrazoles from thiocyanates using phase transfer catalysis
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A very efficient method of preparation for 5-alkyl and 5- arylthiotetrazoles from the corresponding alkyl or aryl halides is described. The halides are first transformed into thiocyanates which further react with azide, yielding the corresponding tetrazoles with [2+3] polar cycloaddition. All synthetic transformations are performed under phase transfer catalytic conditions. The yields vary from good to excellent except for the preparation of 5-benzylthiotetrazole, where the reaction between benzyl thiocyanate and azide [2+3] cycloaddition is in competition with nucleophilic substitution, with benzyl azide as product.
- LeBlanc, Blaise W.,Jursic, Branko S.
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p. 3591 - 3599
(2007/10/03)
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- 1-and 2-(1-Alkyl-1H-tetrazol-5-yl-methyl)-1H-tetrazol-5-thiols and 1-cyanomethyl tetrazole-5-thiol
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Tetrazole thiols represented by the formulae STR1 and the C1 -C3 alkyl derivatives thereof are provided. The tetrazole thiols are useful in the preparation of broad spectrum cephalosporin antibiotics.
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- Bis-tetrazoylmethyl substituted cephalosporin antibiotics
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7β-Acylamino-3-cephem-4-carboxylic acids substituted in the 3-position with a bis-tetrazolemethylthiomethyl group and the corresponding 7α-methoxy cephalosporins represented by the formula STR1 wherein R is an acyl group, R2 is H or OCH3 and R4 is H or C1 -C3 alkyl; are broad spectrum antibiotics useful in the treatment and control of microorganisms pathogenic to man and animals. 7β-Amino nucleus compounds represented when R is hydrogen are intermediates useful in the preparation of the antibiotics where R is acyl.
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