- Method for synthesizing 2,6-diethyl-4-methylphenylacetate
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The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing 2,6-diethyl-4-methylphenylacetate by taking 2,6-diethyl-4-methylbromobenzene as a raw material, which comprises the following steps: firstly reacting 2,6-diethyl-4-methylbromobenzene with n-butyllithium and then conducting reacting with borane trimethyl ester to generate 2,6-diethyl-4-methylphenylboronic acid; and reacting the 2,6-diethyl-4-methylphenylboronic acid with glycine alkyl ester hydrochloride to generate the 2,6-diethyl-4-methylphenylacetate. The preparation method of the 2,6-diethyl-4-methyl phenylacetate provided by the invention has the advantages that the steps are fewer, the use of an expensive noble metal catalyst and a highly toxic cyaniding reagent is avoided, the cost is reduced, the process is simplified, the yield is higher, the defects in the prior art are overcome, and the preparation method is suitable for large-scale industrial production.
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Paragraph 0034; 0036-0037; 0039-0041; 0043
(2021/07/17)
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- Preparation method of pinoxaden
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The invention relates to the field of organic synthesis, in particular to a synthesis method of pinoxaden. The synthesis method comprises the following steps that under catalysis of copper chloride orcuprous chloride, 4-methyl-2,6-diethyl aniline reacts with 1,1-dichloroethylene and nitrous acid ester to generate a compound 1; the compound 1 reacts with sodium alcoholate, and a reaction product is subjected to acidic hydrolysis to obtain a compound 2; the compound 2 reacts with diester carbonate and strong base to obtain an intermediate 3; after diethylene glycol dimethanesulfonate reacts with hydrazine hydrate, salifying with hydrochloric acid is conducted to obtain an intermediate 4; the intermediate 3 and the intermediate 4 are subjected to ring forming under the effect of base to obtain a compound 5; and the compound 5 and pivaloyl chloride react under the effect of the base or base/DMAP to obtain the pinoxaden. The synthesis method of the pinoxaden does not use expensive or toxiccatalysts, does not need to adopt a protection/deprotection strategy, and has the characteristics of low cost and high atomic economy.
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- Palladium-catalyzed cross-coupling of sterically demanding boronic acids with α-bromocarbonyl compounds
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A catalyst system generated in situ from Pd(dba)2 and tri(o-tolyl)phosphine mediates the coupling of arylboronic acids with alkyl α-bromoacetates under formation of arylacetic acid esters at unprecedented low loadings. The new protocol, which involves potassium fluoride as the base and catalytic amounts of benzyltriethylammonium bromideas a phase transfer catalyst, is uniquely effective for the synthesis of sterically demanding arylacetic acid derivatives. (Figure presented)
- Zimmermann, Bettina,Dzik, Wojciech I.,Himmler, Thomas,Goossen, Lukas J.
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experimental part
p. 8107 - 8112
(2011/11/07)
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- Process for Preparing Aryl- and Heteroarylacetic Acid Derivatives
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The present invention relates to a novel process for preparing α-arylmethylcarbonyl compound of the formula (III), characterized in that aryl- and heteroarylacetic acids and derivatives thereof of the formula (I) are reacted with α-halomethylcarbonyl compounds of the formula (II) in the presence of a palladium catalyst, of a phosphine ligand, of an inorganic base and of a phase transfer catalyst, optionally using an organic solvent.
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Page/Page column 5
(2011/08/06)
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- Aryldiones incorporating a [1,4,5]oxadiazepane ring. Part I: Discovery of the novel cereal herbicide pinoxaden
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Derivatives of the new class of 3-hydroxy-4-phenyl-5-oxo-pyrazolines were optimized towards both herbicidal activity on key annual grass weed species and selectivity in small grain cereal crops. The generic structure can be separated into three parts for the analysis of the structure-activity relationships, namely the aryl, the dione with its prodrug forms and the hydrazine moiety. Each area appears to play distinct and different roles in overall expression of biological performance which is further beneficially influenced by adjuvant response and safener action. Pinoxaden 6, a novel graminicide for use in wheat and barley incorporating a [1,4,5]oxadiazepane ring, eventually emerged as a development candidate from the discovery and optimization process.
- Muehlebach, Michel,Boeger, Manfred,Cederbaum, Fredrik,Cornes, Derek,Friedmann, Adrian A.,Glock, Jutta,Niderman, Thierry,Stoller, Andre,Wagner, Trixie
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experimental part
p. 4241 - 4256
(2009/10/02)
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