- Synthesis method of DL-cysteine
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The invention discloses a synthetic method of DLcysteine. The method comprises the following steps: by using acrylonitrile as a raw material, chlorinating to generate 2, 3dichloropropionitrile, hydrolyzing to generate corresponding acid, reacting the acid with thiourea to cyclize to generate 2-aminothiazoline-4-carboxylic acid, adding alkali sulfide to generate 2-mercaptothiazoline-4-carboxylic acid, and hydrolyzing to generate cysteine. The synthesis method provided by the invention has the advantages of short synthesis steps, mild preparation conditions, sufficient and cheap raw material sources and higher product yield.
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Paragraph 0020-0022
(2021/02/13)
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- Preparation and preservation method of 2-chloro-N-n-octyl acrylamide
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The invention discloses a preparation and preservation method of 2-chloro-N-n-octyl acrylamide. The 2-chloro-N-n-octyl acrylamide is an impurity concomitant with production of DCOIT, and the prepared high-purity 2-chloro-N-n-octyl acrylamide has a role in guiding production of the DCOIT. The method comprises that 2,3-methyl dichloropropionate is subjected to three-step reaction of hydrolysis, acylating chlorination and amination dehydrochlorination to obtain the final product, and an antioxidant is added in purification and preservation processes and can prevent polymerization metamorphism of the product.
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Paragraph 0014; 0015
(2017/08/30)
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- Visible Light-Induced Oxidative Chlorination of Alkyl sp3 C-H Bonds with NaCl/Oxone at Room Temperature
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A visible light-induced monochlorination of cyclohexane with sodium chloride (5:1) has been successfully accomplished to afford chlorocyclohexane in excellent yield by using Oxone as the oxidant in H2O/CF3CH2OH at room temperature. Other secondary and primary alkyl sp3 C-H bonds of cycloalkanes and functional branch/linear alkanes can also be chlorinated, respectively, under similar conditions. The selection of a suitable organic solvent is crucial in these efficient radical chlorinations of alkanes in two-phase solutions. It is studied further by the achievement of high chemoselectivity in the chlorination of the benzyl sp3 C-H bond or the aryl sp2 C-H bond of toluene.
- Zhao, Mengdi,Lu, Wenjun
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supporting information
p. 4560 - 4563
(2017/09/11)
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- Ketone-catalyzed photochemical C(sp3)–H chlorination
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Photoexcited arylketones catalyze the direct chlorination of C(sp3)–H groups by N- chlorosuccinimide. Acetophenone is the most effective catalyst for functionalization of unactivated C–H groups while benzophenone provides better yields for benzylic C–H functionalization. Activation of both acetophenone and benzophenone can be achieved by irradiation with a household compact fluorescent lamp. This light-dependent reaction provides a better control of the reaction as compared to the traditional chlorination methods that proceed through a free radical chain propagation mechanism.
- Han, Lei,Xia, Ji-Bao,You, Lin,Chen, Chuo
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p. 3696 - 3701
(2017/06/13)
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- Reaction of (α-halogenoalkyl)thiiranes with nucleophilic reagents I. Reaction with morpholine
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By means of deuterated compounds it was established that (chloromethyl)thiirane reacts with morpholine by a mechanism involving initial opening of the thiirane ring followed by recyclization.In the case of (bromomethyl)thiirane direct substitution of the bromine begins to compete with this mechanism. 2-Methyl-2-(chloromethyl)thiirane, 2,2-dimethyl-3-(chloromethyl)thiirane, and the diastereomeric (1-chloroethyl)thiiranes were synthesized, and their reactivity toward morpholine was studied.
- Tomashevskii, A. A.,Sokolov, V. V.,Potekhin, A. A.
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p. 1610 - 1618
(2007/10/03)
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