- Coordination chemistry with 1-methyl-5: H -tetrazole: Cocrystallization, laser-ignition, lead-free primary explosives-one ligand, three goals
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The synthesis and characterization of 1-methyl-5H-tetrazole (1, MTZ) from 1,5H-tetrazole and methyl iodide is achieved. This neutral ligand was evaluated for its use in energetic transition metal complexes. The formation of complexes is a valuable concept because of their easy synthesis and the large number of possible combinations: (i) metal, (ii) ligand, and (iii) anion. A series of 31 new complexes based on MTZ as the ligand was prepared in order to tune their optical properties and sensitivity values by using seven different metals (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, and Ag+) and six different anions (chloride, nitrate, perchlorate, cyanodinitromethanide, picrate, and styphnate). This variation allows tailoring of the energetic properties of the desired molecule toward e.g. suitable primary explosives or laser-ignitable materials. Obtained compounds were characterized by low temperature single crystal X-ray diffraction, IR spectroscopy, elemental analysis and thermal analysis (DTA, DSC and TGA). The sensitivities toward external stimuli (impact, friction and electrostatic discharge) were determined according to the Bundesamt für Materialforschung und -prüfung (BAM) standard methods. These complexes have been characterized in laser ignition experiments and as new primary explosives. UV-vis measurements of selected complexes were carried out to get a possible insight into the laser initiation mechanism. For the first time a large number of compounds with sensitivities ranging from insensitive to very sensitive were synthesized to give a wide range of new materials for different possible applications.
- Szimhardt, Norbert,Wurzenberger, Maximilian H. H.,Beringer, Andreas,Daumann, Lena J.,Stierstorfer, J?rg
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- 2-Methyl-substituted monotetrazoles in copper(ii) perchlorate complexes: manipulating coordination chemistry and derived energetic properties
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A proposed correlation between coordination chemistry and deduced energetic properties (thermal behaviour, and sensitivities towards mechanical and optical stimuli) of copper(ii) complexes is investigated. Starting from a system comprising Cu(ClO4)2 and either of the ligands 2-methyl-5-aminotetrazole (1, 2-MAT) or 2-methyl-5H-tetrazole (2, 2-MTZ), typically altered parameters like the metal(ii) centre, ligand, or counterion were predefined. Instead, solely slight changes in ligand concentration and the solvent system were implemented in order to provide an insight into structure-property relationships of energetic coordination compounds (ECC) of this type. As a result, five highly energetic complexes [Cu(H2O)2(2-MAT)4](ClO4)2·H2O (3), [Cu(H2O)2(2-MAT)4](ClO4)2 (4), [Cu(H2O)2(2-MAT)4](ClO4)2·2 2-MAT (5), [Cu(ClO4)2(H2O)2(2-MAT)2] (6), and [Cu(H2O)2(2-MTZ)4](ClO4)2 (7) were synthesized and, except for 5, elaborately characterized. Besides structural elucidation via X-ray diffraction, NIR-spectroscopy, differential thermal analysis (DTA), standard sensitivity measurements (impact, friction, and electrostatic discharge), UV/vis-spectroscopy, and optical initiation experiments were conducted to deduce a precise relationship between coordination chemistry and the consequential energetic characteristics of these complexes.
- Zeisel, Lukas,Szimhardt, Norbert,Wurzenberger, Maximilian H. H.,Klap?tke, Thomas M.,Stierstorfer, J?rg
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- Alkylation of 5-(3,3-R,R′-2-oxido-1-triazeneoxymethyl)tetrazoles
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Alkylation of 5-(3,3-R,R′-2-oxido-1-triazeneoxymethyl)tetrazole salts with iodomethane, dimethyl sulfate, chloroacetonitrile, and 1-chloromethoxy-3,3-dimethyl-1-triazene 2-oxide affords two isomers at positions 1 and 2 of the tetrazole ring as the major p
- Gordeev, P. B.,Smirnov, G. A.
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- METHODS OF TREATMENT WITH AMINOLEVULINIC ACID SYNTHASE 2 (ALAS2) MODULATORS
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Described herein is a compound of Formula I or a pharmaceutically acceptable salt thereof: wherein Ring A R1, R2, a, b, and n are as defined herein. Also described is a method of treating a subject having a disorder in need of treatment, comprising inhibiting aminolevulinic acid synthase 2 (ALAS2) in the subject by administering a compound of Formula (I) or a pharmaceutically acceptable salt thereof. Disorders that are of particular interest are blood disorders, such as porphyria and anemia.
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Paragraph 00148
(2020/12/29)
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- Carboxylic acid derivatives, their preparation and use
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Carboxylic acid derivatives STR1 where R-R6, X, Y and Z have the meanings stated in the description, and the preparation thereof, are described. The novel compounds are suitable for controlling diseases.
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- Novel Type Elimination Reactions of Sulfoxides Bearing Several Heteroaromatics: Trapping of Sulfines with 2,3-Dimethyl-1,3-butadiene
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Previously we reported the novel thioaldehydes generation via thermolyses of phenacyl sulfoxides bearing some heteroaromatics. Thermolysis of sulfoxides (1a,b and 2a-4a) bearing other heterocycles such as thiadiazole, triazole, and tetrazole in the presence of 2,3-dimethyl-1,3-butadiene in dioxane at 100 °C led to the unexpected products 6-substituted-5,6-dihydro-3,4-dimethyl-2H-thiapyran 1-oxide (5a,b). These products were considered to be formed by the Diels-Alder reaction of the diene with the sulfines formed initially by the thermal decomposition of the sulfoxides. The rate acceleration and the improvement of the yield by addition of 1.5 equiv of triethylamine, especially in the case of ethoxycabonylmethyl sulfoxide 1c, was observed. The cis-trans selectivity for sulfine cycloadducts was also studied by NMR spectrometry. The reactions of α-substituted phenacyl sulfoxides 1d-f bearing a phenyl-substituted tetrazolyl group in the presence of the same diene were also studied.
- Morita, Hiroyuki,Takeda, Masahiro,Yoshimura, Toshiaki,Fujii, Takayoshi,Ono, Shin,Shimasaki, Choichiro
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p. 6730 - 6737
(2007/10/03)
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- Alkylation, Acylation and Silylation of Azoles
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Performing alkylation, acylation and silylation reactions in separate deprotonation and nucleophilic displacement steps allows for better control of reaction conditions and facilitates problem handling in these processes.In the alkylation of azoles the alkylating agents and solvents possess individual reaction capabilities which seem to be approximately additive.Monoalkylation occurs if the sum of the normalized reaction potentials is equal or larger than the pKa value of the azole.Dialkylation is avoided by keeping the sum of the normalized reaction potentials below the pKa value of the alkylazole.The applicability of these principles is demonstrated by the development of effective procedures for the methylation, benzylation, acetylation, methoxycarbonylation and trimethylsilylation of azoles.
- Begtrup, Mikael,Larsen, Peter
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p. 1050 - 1057
(2007/10/02)
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- INTRODUCTION OF SUBSTITUENTS INTO 5-MEMBERED AZA-HETEROAROMATICS
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With emphasis on mono- and regio-selectively, methods for introduction of substituents at nitrogen and carbon atoms of 5-membered aza-heteroaromatics have been developed.The methods involve application of activation and of assistant groups for direction and protection.Activation has been achieved by the use of quaternary azolium ions and azol-N-oxides as reactive intermediates.If necessary, the N-oxides were further activated by alkylation or acylation.
- Begtrup, Mikael
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p. 573 - 598
(2007/10/02)
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- Synthesis and Properties of Tetrazolium N-Phenacylides
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A number of isomeric tetrazolium 1-phenacylides (6) and 3-phenacylides (7) have been prepared by deprotonation of the corresponding salts (3) and (4) and submitted the standard ylide reactions.A comparison of their physicochemical pr
- Moderhack, Dietrich,Lembcke, Adalbert
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p. 1157 - 1164
(2007/10/02)
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- SYNTHESIS OF 1-SUBSTITUTED TETRAZOLES BY HETEROCYCLIZATION OF PRIMARY AMINES, ORTHOFORMIC ESTER, AND SODIUM AZIDE
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It has been shown that the reaction of heterocyclization of primary amines with orthoformic acid and sodium azide in acetic acid has a rather general character and is a convenient method for the synthesis of 1-substituted tetrazoles.On the basis of experimental data, a probable reaction mechanism is proposed.
- Gaponik, P. N.,Karavai, V. P.,Grigor'ev, Yu. V.
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p. 1255 - 1258
(2007/10/02)
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- Positional Selectivity of the Methylation of 5-Substituted Tetrazolate Anions
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The methylation of a series of 15 sodium 5-substituted tetrazolates using iodomethane in acetone/water (4:1) has been studied.The reaction yields both 1- and 2-methyl products, and the ratio of these products is discussed in terms of the nature of the 5-substituent.Electronic and steric effects dominate the reaction pathway; both increased substituent electronegativity and steric bulk lead to predominant methylation at N 2.Sodium 5-ethoxycarbonyltetrazolate (3n) goes against this trend and an intermediate is proposed where the incoming electrophile is associated with the ester carbonyl group.
- Spear, Robert J.
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p. 2453 - 2468
(2007/10/02)
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- TETRAZOLES. XVI. ALKYLATION OF TETRAZOLES UNDER THE CONDITIONS OF PHASE-TRANSFER CATALYSIS
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The alkylation of tetrazole and 5-substituted tetrazoles with dimethyl sulfate and methyl iodide in the two-phase methylene chloride-water system in the presence of tetrabutylammonium bromide was investigated.The alkylation of tetrazoles with methyl iodide takes place in the organic phase, while that with dimethyl sulfate takes place both in the organic and in the aqueous phases.The ratio of the isomeric tetrazoles formed during the alkylation of 5-aryltetrazoles by methyl iodide correlate with the substituent constants ?.The use of phase-transfer catalysis during the alkylation of tetrazoles does not lead to a change in the selectivity of the reaction.
- Osipova, T. F.,Ostrovskii, V. A.,Koldobskii, G. I.,Erusalimskii, G. B.
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p. 357 - 362
(2007/10/02)
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