- Preparation method of chlorophenoxyacetic ester
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The invention provides a preparation method of chlorophenoxyacetic ester, wherein the preparation method comprises the following steps: A) carrying out reaction of glycolic acid and alcohol in tolueneto obtain glycolic ester; B) carrying out reaction of glycolic ester and metal alkoxide to obtain a metal salt of glycolic ester; and C) carrying out reaction of the metal salt of glycolic ester andchlorobenzene to obtain the chlorophenoxyacetic ester. The chlorophenoxyacetic ester is synthesized by condensation of chlorobenzene with the metal salt of glycolic ester, the use of chlorophenol withunpleasant odor is effectively avoided, the production of highly toxic dioxins is eliminated, and the product quality and the operating environment of the production site are greatly improved. Motherliquor containing effective ingredients cannot be produced, so the loss of effective ingredients is effectively avoided and the yield of the product is improved.
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Paragraph 0052; 0053
(2019/01/08)
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- Bipyridine ligand ruthenium complex is carried and its preparation method and application (by machine translation)
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The invention relates to a novel bipyridine is carried ligand ruthenium complex and its preparation method and in the ester compound hydrogenation is the application of the alcohol compound in the reaction. The use of the bipyridine ligand ruthenium complex catalytic hydrogenation is carried ester compound alcohol compound method is characterized in that: in order to ester compound material in an amount of 0.001 - 0.3 μM % bipyridyl is carried ligand ruthenium complex as catalyst, adding esters compound material in an amount of 1 - 10mol % alkali, in the 25 - 100 °C and 1 - 10MPa hydrogen pressure catalytic hydrogenation under the conditions of ester compound corresponding alcohol compound. The invention of the bipyridine ligand ruthenium complex is carried is convenient to prepare, stable structure, in the ester compound in hydrogenation reaction exhibits excellent catalytic activity. This invention has overcome the ester compound or a non-homogeneous phase catalytic hydrogenation system requires high-temperature high-pressure reaction conditions and high defects of the catalyst amount, catalyst consumption is small, mild reaction conditions, the reaction selectivity is good, improves the economy and the safety of the production system. (by machine translation)
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Paragraph 0098; 0099; 0100; 0102; 0104
(2017/04/28)
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- A general and enantioselective approach to pentoses: A rapid synthesis of PSI-6130, the nucleoside core of sofosbuvir
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An efficient route towards biologically relevant pentose derivatives is described. The de novo synthetic strategy features an enantioselective α-oxidation reaction enabled by a chiral amine in conjunction with copper(II) catalysis. A subsequent Mukaiyama aldol coupling allows for the incorporation of a wide array of modular two-carbon fragments. Lactone intermediates accessed via this route provide a useful platform for elaboration, as demonstrated by the preparation of a variety of C-nucleosides and fluorinated pentoses. Finally, this work has facilitated expedient syntheses of pharmaceutically active compounds currently in clinical use.
- Peifer, Manuel,Berger, Rapha?lle,Shurtleff, Valerie W.,Conrad, Jay C.,Macmillan, David W. C.
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supporting information
p. 5900 - 5903
(2014/05/20)
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- Ruthenium complexes of tetradentate bipyridine ligands: Highly efficient catalysts for the hydrogenation of carboxylic esters and lactones
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A new type of readily available, air-stable ruthenium complex of tetradentate bipyridine ligands has been developed. These complexes displayed exceptional efficiency for the hydrogenation of aromatic and aliphatic carboxylic esters and lactones at as low as 10 ppm catalyst loading under very mild conditions. the Partner Organisations 2014.
- Li, Wei,Xie, Jian-Hua,Yuan, Ming-Lei,Zhou, Qi-Lin
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supporting information
p. 4081 - 4085
(2014/10/15)
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- NOVEL METHOD FOR THE CONVERSION OF CELLULOSE AND RELATED CARBOHYDRATE MATERIALS TO LOW-MOLECULAR-WEIGHT COMPOUNDS
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Methods of converting cellulose or related biorenewable carbohydrate materials into high-value chemical compounds. The methods provide a means of converting low-cost materials such as cellulose and biomass into high yields of compounds such as ethylene glycol, propylene glycol, glycerin, methanol, hydroxyacetone, glycolaldehyde and dihydroxyacetone.
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Page/Page column 9
(2011/06/24)
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- Synthesis and organocatalytic ring-opening polymerization of cyclic esters derived from l-malic acid
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The synthesis of 3-(S)-[(benzyloxycarbonyl)methyl]-1,4-dioxane-2,5-dione (BMD) and 3,6-(S)-[di(benzyloxycarbonyl)methyl]-1,4-dioxane-2,5-dione (malide) from commercially available l-malic acid is reported. Ring-opening polymerization (ROP) studies of BMD are reported showing that the controlled ROP of this monomer is possible in the absence of transesterification side reactions, despite the presence of side-chain esters, using 1-(3,5- bis(trifluoromethyl)phenyl)-3-cyclohexylthiourea and (-)-sparteine to catalyze the polymerization. The ROP of malide with this system was ineffective. Investigation of the effect of initiating species revealed that the electronic nature of the alcohol had a greater effect on the ultimate molecular weight and hence initiator efficiency than steric considerations. Deprotection of the resultant poly(BMD) using H2 and Pd/C resulted in hydrophilic poly(glycolic-co-malic acid)s (PGMAs) that were able to undergo autocatalytic degradation in dilute H2O solution such that complete degradation was observed within 6 days.
- Pounder, Ryan J.,Dove, Andrew P.
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experimental part
p. 1930 - 1939
(2011/03/22)
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- An improved synthesis of cyclic hydroxamic acids from Gramineae
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The boron trichloride sensitive methoxymethyl (MOM) protecting group has been used to efficiently synthesize polymethoxylated derivatives of the benzoxazinone family of cyclic hydroxamic acids. The MOM group allows the unveiling of the hemiacetal at C-2 of these compounds without demethylating ring methoxy substituents, resulting in greatly increased yields.
- Tays, Kevin,Atkinson, Jeffrey
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p. 903 - 912
(2007/10/03)
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- HOMOGENEOUS CATALYTIC HYDROGENATION OF DICARBOXYLIC ACID ESTERS. II
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Hydrogenation of dimethyl oxalate in the presence of Ru(CO)2(CH3COO)2(PBu3)2 gives methyl glycolate and subsequently ethylene glycol.The formation of the glycol is favoured by hydroxylated solvents.
- Matteoli, Ugo,Menchi, Gloria,Bianchi, Mario,Piacenti, Franco
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p. 233 - 238
(2007/10/02)
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- Novel ester derivatives of ether polycarboxylic acids and process for making same
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Novel polyfunctional compounds which may be hydrolyzed to the corresponding salts, which in turn are metal sequestering agents, are disclosed, as well as a novel method for their preparation. The compounds are the reaction product obtained from the reaction of selected salts of monoalkyl esters of maleic acid with selected active hydrogen containing compounds. These products are prepared by a reaction of the starting materials in preferably a substantially anhydrous medium at an elevated temperature.
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