- Preparation method of pymetrozine
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The invention provides a preparation method of pymetrozine. The preparation method comprises the following steps: carrying out a hydrazide reaction on carbonic acid diester and hydrazine hydrate to prepare carbohydrazide, carrying out a condensation reaction on the obtained carbohydrazide and 3-formyl pyridine to prepare pyridin-3-yl methylene carbohydrazide, and finally, carrying out a cyclization reaction on pyridin-3-yl methylene carbohydrazide and monochloroacetone to prepare pymetrozine. The method has the advantages of cheap and easily-available raw materials and low cost; technologicalprocess is simple and short, and pymetrozine can be prepared only through three steps; operation is safe and simple, and reaction conditions are easy to realize; little process wastewater is generated, and the method is environment-friendly; the related raw materials and intermediate products are high in stability, high in reaction selectivity, few in side reactions and high in target product yield and purity, and industrial production of pymetrozine is facilitated.
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Paragraph 0055-0056
(2020/11/26)
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- Carbonyl dihydrazone derivative, preparation method and applications thereof
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The invention relates to a carbonyl dihydrazone derivative represented by a chemical structural formula I, and a pharmaceutically acceptable salt thereof, a pharmaceutical composition and applicationsin preparation of influenza virus neuraminidase inhibitors, wherein the formula I is defined in the specification, and R is selected from hydroxyl, dihydroxyl, 2-hydroxyl-3-methoxy, 2-hydroxyl-4-methoxy, 2-hydroxyl-5-methoxy, 2-hydroxyl-6-methoxy, 3-hydroxyl-2-methoxy, 3-hydroxyl-4-methoxy, 3-hydroxyl-5-methoxy, 3-hydroxyl-6-methoxy, 4-hydroxyl-2-methoxy, 4-hydroxyl-3-methoxy, 4-hydroxy-3,5-dimethoxy, 2-hydroxy-3-ethoxy, 2-hydroxy-4-ethoxy, 2-hydroxy-5-ethoxy, 2-hydroxy-6-ethoxy, 3-hydroxy-2-ethoxy, 3-hydroxy-4-ethoxy, 3-hydroxy-5-ethoxy, 3-hydroxy-6-ethoxy, 4-hydroxy-2-ethoxy, 4-hydroxy-3-ethoxy, 4-hydroxy-3,5-diethoxy, trihydroxy and 4-hydroxy-3,5-dimethyl.
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Paragraph 0027-0031
(2020/04/02)
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- Continuous hydrazide preparation method
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The invention relates to a continuous hydrazide preparation method. The preparation method includes: in a micro-channel reactor or a pipeline reactor, subjecting esters, anhydrides or acyl chloride tocontinuous reaction with hydrazine or solution of hydrazine under a solvent-free condition or in a solvent to prepare a hydrazide compound. The preparation method is simple, short in technical process, less in waste gas, wastewater and industrial residues, beneficial to environmental production and suitable for industrial production. The adopted reactor is short in reaction time, high in safety and capable of realizing continuous production. The adopted reactor is high in workshop space utilization rate, and large-scale production can be realized. By adoption of the preparation method, solvent recycling can be realized, and production cost is reduced; in addition, high raw material conversion rate, high quality stability and high purity are realized.
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Paragraph 0054-0056; 0087-0089
(2019/04/17)
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- Method for preparing pymetrozine
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The invention discloses a method for preparing pymetrozine with an aim to provide a synthesis method short in reaction route of the pymetrozine, small in environmental pollution and simple in technology operation, and belongs to the technical field of organic synthesis. The method includes the steps of 1), allowing dimethyl carbonate serving as a raw material to be subjected to hydrazinolysis withhydrazine hydrate to obtain carbazide; 2), subjecting carbazide and smoke aldehyde to condensation reaction to obtain (E)-N'-(pyridine-3-kiya methyl) hydrazine carbon hydrazide; 3), subjecting (E)-N'-( pyridine-3-kiya methyl) hydrazine carbon hydrazide and chloroacetone to condensation reaction to obtain (E)-N'-(Z)-1-chloropropyl-2-subunit)-2-(pyridine-3-kiya methyl) diazanyl-1-carbohydrazide; 4), subjecting (E)-N'-(Z)-1-chloropropyl-2-subunit)-2-(pyridine-3-kiya methyl) diazanyl-1-carbohydrazide to ring formation under the alkaline condition to obtain the pymetrozine.
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Paragraph 0052; 0057; 0062
(2018/11/22)
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- An efficient protocol for the production of pymetrozine via a new synthetic strategy
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A practical four-step synthesis of pymetrozine is reported, starting from a green chemical dimethyl carbonate and using the key intermediate methyl (E)-1-(2-oxopropyl)-2-(pyridin-3-ylmethylene)hydrazine-1-carboxylate. The main advantages of the route include inexpensive starting materials, environmental friendliness, short synthetic route, easy-to-use synthetic method and acceptable overall yield. A scale-up experiment was carried out to provide pymetrozine with 99.84% purity in 53.2% total yield.
- Zhou, Qifan,Du, Fangyu,Shi, Yajie,Liu, Wenqiang,Liu, Dongdong,Chen, Guoliang
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p. 434 - 438
(2018/09/12)
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- Nitrogen-rich salts of 1H,1′H-5,5′-Bitetrazole-1,1′-diol: Energetic materials with high thermal stability
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1H,1′H-5,5′-Bitetrazole-1,1′-diol was synthesized starting from glyoxal, which is converted to glyoxime after treatment with hydroxylamine. Chlorination of glyoxime with Cl2 gas in ethanol and following chloro/azido exchange yields diazidoglyoxime, which is cyclized under acidic conditions (HCl gas in diethyl ether) to give 1H,1′H-5,5′- bitetrazole-1,1′-diol dihydrate (1). A large variety of nitrogen-rich salts of 1 such as the diammonium (2), the dihydrazinium (3), the bis-guanidinium (4), the bis(aminoguanidinium) (5), the diaminoguanidinium salt monohydrate (6), the triaminoguanidinium salt monohydrate (7), the 1-amino-3-nitroguanidinium salt dihydrate (8), the diaminouronium salt monohydrate (9), the bis(oxalyldihydrazidinium) (10), the oxalyldihydrazidinium salt dihydrate (11), the 3,6-dihydrazino-1,2,4,5-tetrazinium (12), the 5-aminotetrazolium (13), the bis(5-amino-1-methyl-1H-tetrazolium) salt (14), the bis(5-amino-2-methyl-2H-tetrazole) adduct (15), and the 1,5-diaminotetrazolium salt (16) were synthesized by means of Bronsted acid-base or metathesis reactions. All compounds were fully characterized by vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC) measurements. The crystal structures of 1-16 could be determined by using single-crystal X-ray diffraction. The heats of formation of 1-16 were calculated by using the atomization method on the basis of CBS-4M enthalpies. With regard to their potential use as cyclotrimethylene trinitramine (RDX) or hexanitrostilbene (HNS) replacements, several detonation parameters such as the detonation pressure, detonation velocity, explosion energy, and explosion temperature were computed using the EXPLO5 code on the basis of the experimental (X-ray) densities and calculated heats of formation. In addition, the sensitivities towards impact, friction, and electrical discharge were tested using the BAM drop hammer, a friction tester, as well as a small-scale electrical discharge device. Copyright
- Fischer, Niko,Klapoetke, Thomas M.,Reymann, Marius,Stierstorfer, Joerg
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p. 2167 - 2180
(2013/06/04)
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- Efficient synthesis of 1-(5′-acylamino-1′,3′,4′- thiadiazol-2′-yl)-4-acyl-thiosemicarbazides
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Acyl chlorides reacted with ammonium thiocyanate and carbonic dihydrazide under phase-transfer catalysis to first afford 2,2′- bis(acylaminothiocarbonyl)-carbonic dihydrazides, which further cyclized in the presence of glacial acetic acid to efficiently give 1-(5′-acylamino- 1′,3′,4′-thiadiazol-2′-yl)-4-acyl-thiosemicarbazides in high yield. Copyright Taylor & Francis Group, LLC.
- Li, Zheng,Yang, Jing-Ya,Wang, Xi-Cun
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p. 2355 - 2362
(2007/10/03)
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- Green synthetic method for 1,5-disubstituted carbohydrazones
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A green synthetic method for 1,5-disubstituted carbohydrazones is described. The reaction of dimethyl carbonate with hydrazine hydrate first gave carbohydrazide, which further reacted with various aromatic aldehydes or aliphatic ketones under solvent-free conditions to efficiently afford 1,5-disubstituted carbohydrazone. This protocol has the advantages of using nontoxic dimethyl carbonate as starting material, no use of organic solvents, short reaction time, high yield, and simple workup procedure. Copyright Taylor & Francis Group, LLC.
- Li, Zheng,Zhu, Wei,Yu, Jinlan,Ma, Xuelin,Lu, Zhong,Xiao, Shuxiu
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p. 2613 - 2619
(2007/10/03)
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- Aryl substituted heterocycles
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The present invention concerns the novel use of aryl substituted heterocycles of formula I, set out below, which antagonize the pharmacological actions of one of ent endogenous neuropeptide tachykinins an the neurokinin 2 (NK2) receptor making them useful whenever such antagonism is desired, such as in the treatment of asthma and related conditions. The invention also provides pharmaceutical compositions containing the aryl substituted heterocycles for use in such treatment. Certain novel aryl substituted heterocycles of formula I and novel intermediates for their manufacture are also provided. STR1
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- Bifunctional linking compounds, conjugates and methods for their production
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The present invention provides novel N-substituted hydrazine bifunctional compounds, novel N-subhstituted hydrazone derivatives of a cytotoxic reagent incorporating the bifunctional compounds, novel conjugates containing at least one cytotoxic reagent molecule reacted with the bifunctional compound and bound to a molecule reactive with a target cell population, methods for their production, and pharmaceutical compositions and methods for delivering cytotoxic reagents to a target population of cells. The hydrazone bonds of the conjugates of the invention permit the release of free cytotoxic reagent from the conjugates in the acidic external or internal environment of the target cells. The bifunctional compounds, derivatives, conjugates and methods of the invention are useful in antibody-or ligand-mediated drug delivery systems for the perferential killing of a target cell population to treat diseases such as cancers, infections and autoimmune disorders.
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- A SPECTRAL STUDY OF URANYL(VI) COMPLEXES OF HYDRAZIDES AND HYDRAZONES
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Metal complexes of uranyl(VI) with nitrogen and oxygen containing bidentate and tridentate ligands, carbohydrazide (CHZ), 1,5-diphenylcarbazide (DPC), terephthalic acid hydrazide (TDH) and bis-benzaldehyde terephthalic hydrazone (BBTH) have been studied. The complexes of carbohydrazide and 1,5-diphenylcarbazide in 1:2 metal to ligand molar ratio, whereas TDH and BBTH complexes in 1:1 molar ratio have been synthesized. All the complexes have been characterized as seven-coorinated UO2(VI) systems, in which these ligands coordinate through carbonyl and terminal amino groups. All the complexes show bands in the region 830-840 and 910-920 cm-1, which are assigned to νsym. and νasym. UO2 vibrations.
- Chandra, Ramesh,Kapoor, Ramesh N.
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p. 1125 - 1132
(2007/10/03)
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- Synthesis and characterization of complexes of a Schiff base formed by condensation of carbohydrazide and isatin (H2ICA)
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The synthesis and characterization of MnII, CoII, NiII, CuII, ZnII, CdII and UO22+ complexes of bis(isatin) carbohydrazone (H2ICA) are reported.Elemental analysis, molar conductance, magnetic moment and spectral (IR, visible and NMR) measurements have been used to characterize the complexes.IR spectral data show that the ligand behaves in a bi, tri, tetra, and pentadentate manner.An octahedral structure is proposed for the MnII, NiII and Co (HICA)2*H2O complexes, a tetrahedral structure for a Co(ICA)2H2O complex and a square planar structure for the CuII complexes. Keywords: metal complexes / isatin carbohydrazone / bi, tri, tetra, and pentadentate ligand
- El-Reash, G. M. Abu,Ibrahim, K. M.,Taha, F. I.,Feteih, N. A.
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p. 846 - 849
(2007/10/02)
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- AZA ANALOGS OF CARBOXYALKYL DIPEPTIDE DERIVATIVES AS ANTIHYPERTENSIVES
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There are disclosed aza analogs of carboxyalkyl dipeptide derivatives and related compounds which are useful as converting enzyme inhibitors and as antihypertensives said compounds being represented by the general formula: STR1 wherein A and B can be joined together to form various ring structures.
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- Process for making carbohydrazide
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Disclosed is a process for making carbohydrazide by reacting a di(lower alkyl) carbonate with hydrazine in two-stages with an intermediate step of removing the corresponding lower alkanol formed as a co-product in the first stage. The two reaction stages are carried out at relatively low temperatures (i.e. below about 80° C.).
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