- A preparation method of the clonidine hydrochloride
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The invention discloses a method for preparing the clonidine hydrochloride, including intermediates 1 synthesis, intermediate 2 synthesis and clonidine hydrochloride synthetic three steps, the present invention in order to 2, 6 - dichloroaniline as raw materials, through the hydroformylation reaction get intermediate 1, "one-pot" get clonidine free base, finally with hydrogen chloride ethanol solution into salt clonidine hydrochloride. By processing the raw material synthetic process, by utilizing the free alkali in the course of refining into salt after adjusting pH, and the clonidine hydrochloride is used for purification of the pulping process control such as ethyl acetate, to obtain a high-purity clonidine hydrochloride preparation method. The method not only improves the product purity and yield, impurity can also effectively control, but also greatly reducing the cost, simplifying the process, is more suitable for industrial production.
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Paragraph 0046; 0053; 0058; 0059; 0060
(2018/04/28)
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- 1-(2,6-dichlorophenyl)-3-(substituted pyrimidine-4-yl)urea compound and preparation and application thereof
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The invention discloses a 1-(2,6-dichlorophenyl)-3-(substituted pyrimidine-4-yl)urea compound and preparation and application thereof. The structure of the compound is shown in a formula (I). The compound has no toxicity function on the proliferation of B
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Paragraph 0033-0036; 0041-0043
(2019/01/08)
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- Simultaneous identification of Fenton degradation by-products of diclofenac, ibuprofen and ketoprofen in aquatic media by comprehensive two-dimensional gas chromatography coupled with mass spectrometry
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Diclofenac, ibuprofen and ketoprofen are anti-inflammatory drugs intensively used both in human and animal treatment. Due to their high stability these compounds are partially removed by wastewater treatment plants and from this reason the development of some alternative treatments such as advanced oxidative processes are necessary. The main problems in the optimization of an advanced oxidative process rise from the difficulties which appear in the identification of degradation by-products necessary for the establishment of degradation pathway. In this paper a developed method for the simultaneous identification of Fenton degradation by-products of the three above mentioned pharmaceuticals is presented. The obtained results show the comprehensive two-dimensional gas chromatography coupled with mass spectrometry as a proper method for the analysis of the complex mixture of compounds resulted from the Fenton degradation process. Moreover, some compounds never mentioned in the scientific literature were identified. (Chemical Equation Presented).
- Beldean-Galea, Mihail Simion,Coman, Virginia,Copaciu, Florina,Thiébaut, Didier,Vial, Jér?me
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p. 1021 - 1027
(2015/07/15)
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- Methylation of imidazoline related compounds leads to loss of α2-adrenoceptor affinity. Synthesis and biological evaluation of selective I1 imidazoline receptor ligands
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Methylated analogues of imidazoline related compounds (IRC) were prepared; their abilities to bind I1 imidazoline receptors (I1Rs), I2 imidazoline binding sites (I2BS) and α2-adrenoceptor subtypes (α
- Schann, Stephan,Greney, Hugues,Gasparik, Vincent,Dontenwill, Monique,Rascente, Carla,Lacroix, Gabriel,Monassier, Laurent,Bruban, Veronique,Feldman, Josiane,Ehrhardt, Jean-Daniel,Bousquet, Pascal
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experimental part
p. 4710 - 4715
(2012/09/22)
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- Screw Sense Selective Polymerization of Achiral Isocyanides Catalysed by Optically Active Nickel(II) Complexes
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Poly(isocyanides), (RN=Cn, can be prepared from isocyanides, , by the catalytic action of nickel(II) compounds.The main chain of these polymers is a rigid helix.This helical conformation results from a restricted rotation around the single bonds that connect the main-chain carbon atoms.Polymerization of achiral isocyanides generally gives a racemic mixture of left- and right-handed helices, whereas polymerization of optically active isocyanides results in helices with an excess of one screw sense.We describe a procedure for obtaining poly(isocyanides) with predominantly one screw sense, starting from an achiral monomer.A catalyst is prepared by adding an optically active amine to a tetrakis(isocyanide)nickel(II) perchlorate complex.Polymerization of various achiral isocyanides with this catalist yields optically active polymers with an enantiomeric excess up to 83percent.
- Kamer, Paul C. J.,Nolte, Roeland J. M.,Drenth, Wiendelt
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p. 6818 - 6825
(2007/10/02)
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- Trimethylacetic formic anhydride. Improved preparation and use as a highly efficient and selective N-formylating reagent
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The title compound was prepared from trimethylacetyl chloride and sodium formate in the presence of 18-crown-6.The mixed anhydride proved to be a very useful reagent for the N-formylation of amines.Even amines which are unstable when deprotonated can be formylated.
- Vlietstra, Edward J.,Zwikker, Jan W.,Nolte, Roeland J. M.,Drenth, Wiendelt
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p. 460 - 462
(2007/10/02)
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- 3-Anilino-2,4-diazabicyclo[3.2.1]octenes
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Novel 3-anilino-2,4-diazabicyclo[3.2.1]octenes, physiologically tolerable acid addition salts thereof and method of preparing same are described. These compounds are useful as tranquilizers, diuretics and antihypertensives.
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