- Novel synthetic method of D/L-phenyl glycine
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The invention relates to a novel synthetic method of D/L-phenyl glycine. An existing synthetic method of D/L-phenylglycine is used for producing D/L-phenyl glycine by using highly toxic raw materials,and the synthetic method is harmful. According to the synthesis method, benzene is used as a solvent and a raw material. The method comprises the following steps: firstly, performing Friedel-Crafts alkylation reaction between benzene and dichloroacetic acid or bromochloroacetic acid under the catalystic function of a catalyst, wherein the reaction temperature of Friedel-Crafts alkylation reactionis 55-60 DEG C, the reaction time is 7h, and after Friedel-Crafts alkylation reaction, a benzene solution of alpha-chlorophenylacetic acid or alpha-bromophenylacetic acid is obtained; separating thereaction product into a water phase by using 20% ammonia water; adding urotropin into the water phase to carry out catalytic reactions at a temperature of 75-80 DEG C for 12 hours, controlling the temperature to be 70-80 DEG C, neutralizing the solution by 30% sulfuric acid until the pH value is equal to 6.5 to obtain a D/L-phenyl glycine water solution, and performing suction filtration to obtaina filter cake, namely D/L-phenyl glycine. Cyanide is not used, production is safe, energy consumption is reduced, and the raw material quality standard of downstream products is met.
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Paragraph 0016-0019; 0022
(2020/04/22)
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- Α-chloro -4 fluoro phenyl benzylone method for the synthesis of
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The invention relates to the field of chemistry, particularly to the field of medicinal chemistry, more particularly to a synthetic method for alpha-chlorine-4fluorine phenyl benzyl ketone, and aims to solve the problems that in the traditional preparation technology, the cost for preparing phenylacetic acid synthetic compound is high, the technology is complicated and the technology is not suitable for industrial production. The invention provides a novel synthetic method for alpha-chlorine-4fluorine phenyl benzyl ketone through adopting mandelic acid, which includes the following steps: alpha position chloro takes as the first step reaction, corresponding synthetic parameters are matched, and the mandelic acid takes as a starting material for synthesizing compound (4). Therefore, the total yield reaches 67.8% after three-step synthesis, by-products generated in the reaction are reduced, the purity of a target object is high, the purification is easy, and the method is suitable for industrial production.
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Paragraph 0026; 0027
(2017/04/28)
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- Kinetic resolution of α-bromophenylacetamides using quinine or Cinchona alkaloid salts
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The kinetic resolution of racemic α-bromophenylacetamides 1 was achieved in the presence of benzenethiolate and Cinchona alkaloid salts as phase-transfer catalysts or benzenethiol and quinine, yielding (S)-enantioenriched α-sulfanylated products. The observed stereoselection was rationalized on the basis of the best fitting of 1 and the resolving agent in the ternary complexes.
- Marzorati, Liliana,Fejfar, Jose L.,Tormena, Claudio F.,Vitta, Claudio Di
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scheme or table
p. 748 - 753
(2012/09/05)
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- CO2 anion-radical in organic carboxylations
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This letter shows a first approximation to the use of CO2 anion-radical in the obtention of α-methyl and α-ethylcyanoacetic acids from propionitrile and butyronitrile, respectively, through a paired electrochemical reaction with CO2. The electrosynthesis of α-chloro-phenylacetic acid from benzyl chloride and phenylacetic acid from toluene by another proposed pathway is also discussed.
- Otero, M. Dolores,Batanero, Belen,Barba, Fructuoso
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p. 2171 - 2173
(2007/10/03)
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- Attempts to Prepare an Alkynyldiazonium Salt
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The 2-bromo-1-chloroalkanal p-tosylhydrazones 11a and b react with triethylamine as base to give the azoalkenes 12, of which (1-chloro-2-phenylethenyl)tosyldiazene (12b) is obtained as a crystalline material at room temperature. 12b reacts with SbCl5 at -30 and -70 deg C to form different diazonium salts, which are treated with nucleophiles such as methanol and water.The products obtained (Schemes 3 and 4) indicate the formation of the phenylethenyldiazonium salt 20, which is stable up to -20 deg C. 20 adds nucleophiles like methanol or water as well as anisole at the CC triple bond before releasing nitrogen.
- Helwig, Reinhard,Hanack, Michael
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p. 1008 - 1021
(2007/10/02)
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- ELECTROCHEMICAL CARBOXYLATION OF BENZAL CHLORIDE
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The electrocarboxylation of benzal chloride to α-chlorophenylacetic and phenylmalonic acids is realized in diaphragmless cells with aluminium sacrificial anodes.Yields respectively up to 50 percent and 30 percent can be obtained.Phenylacetic acid is always present among the products.
- Silvestri, G.,Gambino, S.,Filardo, G.,Greco, G.,Gulotta, A.
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p. 4307 - 4308
(2007/10/02)
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- Chlorinations with Carbon Tetrachloride under Conditions of Phase Transfer Catalysis
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Anion of ketones, sulfones and esters were α-chlorinated by carbon tetrachloride under conditions of phase transfer catalysis (PTC).Alcohols were unreactive.The observed products show that secondary reactions took place in many cases.The chlorination of the sulfone cis-2,5-diphenyltetrahydrothiophene-1,1-dioxide (1) occurred with inversion to give trans-2,5-dichloro-2,5-diphenyltetrahydrothiophene-1,1-dioxide (2).The structures of cis-1 and trans-2 were determined by X-ray diffraction.The reaction conditions are also applicable to brominations using bromotrichloromethane.
- Lauritzen, Stein Erik,Roemming, Christian,Skatteboel, Lars
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p. 263 - 268
(2007/10/02)
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- Studies on the rearrangement of (trichloromethyl)carbinols to α-chloroacetic acids
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Phenyl(trichloromethyl)carbinol undergoes an unimolecular, predominantly intramolecular conversion into potassium α-chlorophenylacetate on stirring with 10percent aqueous potassium hydroxide at 0 deg C for several days.Besides providing an interesting example of a 1-2 chlorine shift, the reaction is of potential importance for the synthesis of α-chloro acids.The study of a variety of (trichloromethyl)carbinols shows the reaction is general for secondary (trichloromethyl)carbinols as well as trichloroethanol.The mechanism of the reaction involves the preliminary formation of an epoxide.Several mechanisms are considered for the conversion of the epoxide to the α-chloroacetate anion, but none accounts for all of the experimental facts.Tertiary carbinols break down at the epoxide stage into a ketone and carbon monoxide.
- Reeve, Wilkins,McKee, James R.,Brown, Robert,Lakshmanan, Sitarama,McKee, Gertrude A.
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p. 485 - 493
(2007/10/02)
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- TRANSFERT DE PHASE SOLIDE- LIQUIDE : INFLUENCE DE L'AGENT DE TRANSFERT SUR LA REACTION DE FORMATION DE CYCLOPROPANES
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Cyclopropanic esters are obtained in a solid- liquid medium, in the presence of a phase- transfer reagent.The stereoselectivity results are interpreted by a reaction in the organic solvents.
- Artaud, I.,Seyden-Penne, J.,Viout, P.
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p. 613 - 616
(2007/10/02)
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- 3-Alkylsilyl-2-oxazolidonone compounds and synthesis thereof
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Silylating agents, such as 3-alkylsilyl-2-oxazolidinones, are useful for the preparation of penicillins and cephalosporins at low temperatures and in a short time. The process for preparing these compounds comprises reacting 2-oxazolidinone or 5-methyl-2-oxazolidinone with trimethylchlorosilane, dimethylchlorosilane or triethylchlorosilane, in the presence of an organic tertiary base acting as a hydrogen chloride removal agent.
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