- Crystal structures of mono-, Di-, and triaminoguanidinium sulfate, as well as azidoformamidinium sulfate: Important precursors for syntheses of nitrogen rich ionic vompounds
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Bis(1-aminoguanidinium) sulfate monohydrate (AG2SO4 H2O, 1), bis(1,3-diamino-guanidinium sulfate (DAG2SO 4, 2), bis(1,3,5-triaminoguanidinium) sulfate dihydrate (TAG 2SO4 2 Hsub
- Klapoetke, Thomas M.,Mayer, Peter,Stierstorfer, Joerg
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- Thermally stable energetic salts based on 3-nitramino-4-tetrazolefurazan
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In order to develop new energetic materials with high energy and low sensitivity, a series of nitrogen-rich energetic salts based on 3-nitramino-4-tetrazolefurazan were conveniently synthesized through nitration, neutralization and metathesis reaction. All energetic salts were fully characterized by NMR (1H, 13C), IR and elemental analysis. Furthermore, ammonium salt (2) was confirmed by 15N NMR and hydroxylammonium salt (5) was confirmed by single-crystal X-ray diffraction. Salt 5 crystallized in triclinic space group P1 with four hydroxylammonium cations and two NATF anions per unit cell at a density of 1.815 g cm-3. The densities of the salts are in the range of 1.621 (6) to 1.815 g cm-3 (5). Due to the two nitrogen-rich cations in the salts, they show high positive enthalpies of formation falling between 299.2 kJ mol-1 (2) and 1040.6 kJ mol-1 (9). All the salts show good thermal stabilities with the decomposition temperatures ranging from 203 °C (4) to 284 °C (6). The impact sensitivities of the energetic salts lie between 5 J (2 and 5) and >40 J (6, 7, 8) and their friction sensitivities range from 108 N (4) to >360 N (6). Their detonation performances were calculated according to Kamlet-Jacobs equations. The detonation pressures of the synthesized energetic salts were found to be in the range of 21.1 GPa (6) to 34.7 GPa (5) and their detonation velocities are between 7117 m s-1 (6) and 8826 m s-1 (5).
- Huang, Haifeng,Shi, Yameng,Li, Ying,Liu, Yanfang,Yang, Jun
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- Improved synthesis process for lamotrigine
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The invention discloses an improved synthesis process for lamotrigine. The process comprises the following steps: (1) synthesizing 2,3-dichlorobenzoyl cyanide: adding 2,3-dichlorobenzoic acid and thionyl chloride into a reactor, carrying out depressurized evaporating to remove thionyl chloride after a reaction is completed, adding cuprous cyanide into the reactor, and filtering out solids after a reaction is completed, so as to obtain a 2,3-dichlorobenzoyl cyanide solution; (2) preparing a condensate: adding aminoguanidine carbonate and an entrainer into a reactor, dropwise adding concentrated sulfuric acid, distilling off the entrainer and water, carrying out suction filtration, enabling solids to enter a reaction bottle, carrying out depressurized pumping, then, adding the 2,3-dichlorobenzoyl cyanide solution obtained in the step (1) into the reaction bottle, cooling the reaction bottle to room temperature after a reaction is completed, and carrying out suction filtration, so as to obtain the condensate; and (3) preparing cyclics: adding liquid alkali into the condensate obtained in the step (2), and carrying out crystallizing, filtering, washing and baking after a reaction, thereby obtaining the lamotrigine. According to the improved synthesis process for the lamotrigine, the quality and yield of the product, i.e., the lamotrigine can be remarkably increased, and the yield reaches 90% or more.
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Paragraph 0032
(2017/07/21)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- The synthesis of 5,7-dimethyl-1,2,4-triazolo[1,5a(14C)] pyrimidine-2-carbaldehyde from [14C]aminoguanidine: A key intermediate for the radiochemical GMP synthesis of a drug candidate
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Hydrazination of barium [14C]cyanamide and hydrazinolysis of S-methylisothio[14C]urea were compared for their ability to efficiently prepare [14C]aminoguanidine bicarbonate. [ 14C]Aminoguanidine bicarbonate was converted in three steps to 5, 7-dimethyl-1,2,4-triazolo[1,5a(14C)]pyrimidine-2-carbaldehyde, a key radiochemical GMP starting material. Copyright
- Rane, Anil M.,Klaas, Schildknegt
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scheme or table
p. 257 - 260
(2011/05/06)
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