- Novel method for preparing 2,4,5-trifluoro phenylacetic acid
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The invention provides a novel method for preparing 2,4,5-trifluoro-phenylacetic acid. The novel method specifically comprises the following steps: (1) dissolving 1,2,4-trifluoro benzene into 1,2-dihalogenated ethane, carrying out a Friedel-crafts alkylation reaction under catalysis of a lewis acid catalyst, thus preparing 2,4,5-trifluoro halogenated ethylbenzene; (2) hydrolyzing the 2,4,5-trifluoro halogenated ethylbenzene obtained in the step (1) in an alkaline system, thus obtaining 2,4,5-trifluoro phenethyl alcohol; (3) oxidizing the 2,4,5-trifluoro phenethyl alcohol obtained in the step (2), thus obtaining the 2,4,5-trifluoro phenylacetic acid. The novel method disclosed by the invention has the advantages that raw materials are easy to obtain, the reaction is mild, the operation is easy, the cost is low, environment friendliness is realized, no high-toxicity reagent exists, and the like.
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Paragraph 0046; 0047
(2017/08/29)
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- A west he row sandbank chiral intermediate and asymmetric synthesis method
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The invention relates to a sitagliptin chiral intermediate and an asymmetric synthesis method thereof. The asymmetric synthesis method comprises the steps: with 2,4,5-trifluorophenyl acetic acid as a starting material, carrying out a reduction reaction to obtain 2-(2,4,5-trifluorophenyl)ethanol, then carrying out a reaction with an oxidant, carrying out condensation of the product without separation and (R)-(+)-tert-butyl sulfinamide to obtain corresponding acetal, carrying out a reaction of the obtained product with dialkyl malonate to obtain a key chiral intermediate, hydrolyzing to obtain a corresponding organic amine, carrying out a reaction of the amine with caustic alkali and then acidifying to obtain a corresponding carboxylic acid, then carrying out condensation with 3-(trifluoromethyl)-5,6,7,8- tetrahydro-[1,2,4] triazolo[4,3-a]pyrazine hydrochloride to obtain sitagliptin tert-butyl oxanamide, and finally deprotecting with hydrochloric acid to obtain sitagliptin. The yields of all the steps are all higher, the used reagents are all conventional cheap reagents, no expensive chiral catalysts are used, the reaction conditions are quite mild, and the asymmetric synthesis method is suitable for industrialization.
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Paragraph 0041; 0045; 0046; 0047; 0048-0050; 0062-0065
(2017/08/25)
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- A west he row sandbank and its salt synthesis method (by machine translation)
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The invention discloses a west he row sandbank and its salt synthesis method, in order to 2, 4, 5 - trifluorobenzene acetic acid as the starting material, through esterification, reduction, oxidation and Witting reaction, to obtain 4 - (2, 4, 5 - trifluorophenyl) - 2 - butene ethyl ester, or passes through the reduction, oxidation and Witting reaction after, to obtain 4 - (2, 4, 5 - trifluorophenyl) - 2 - butene ethyl ester. Then in BuLi or six methyl two silicon and nitrogen under the action of the alkane-sodium, with chiral amine on the hydroamination reaction, framed asymmetric amination product, through ester, condensation, hydrogenated three-step reaction to obtain sitagliptin. The west he of the spit of fland synthesis method of raw materials are cheap and easy to obtain, steps are less, the operation is easy, can be effectively reduced. The method can be the high purity of the sitagliptin, the salt of the phosphoric acid obtained after HPLC purity and sitagliptin ee values are in 99% or more, can be applied to the medical field. (by machine translation)
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Paragraph 0061; 0062; 0063; 0064; 0065
(2017/08/04)
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- NOVEL BETA-SULFINAMINO MALONATE DERIVATIVES AND PROCESS FOR PREPARING THE SAME, AND PROCESS FOR PREPARING SITAGLIPTIN USING THE SAME
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The present invention relates to beta-sulfinamino malonate derivatives having a high diastereomeric ratio (DR) value manufactured through a stereoselective addition reaction of chiral sulfinyl imine and malonate derivatives, to optically pure Sitagliptin by using the same, and to a method for manufacturing pharmaceutically acceptable salt thereof. According to the present invention, the method is capable of manufacturing novel beta-sulfinamino malonate derivatives which are intermediate in the manufacture of Sitagliptin, with high optical purity and high yields without using a solvent under mild conditions, and ultimately manufacturing optically pure Sitagliptin in an efficient manner by using the same.COPYRIGHT KIPO 2016
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Paragraph 0141-0143
(2021/06/22)
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- PYRIDIN-3-YL ACETIC ACID DERIVATIVES AS INHIBITORS OF HUMAN IMMUNODEFICIENCY VIRUS REPLICATION
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The disclosure generally relates to compounds of formula I, II, III and IV, including compositions and methods for treating human immunodeficiency virus (HIV) infection. The disclosure provides novel inhibitors of HIV, pharmaceutical compositions containing such compounds, and methods for using these compounds in the treatment of HIV infection.
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Paragraph 0115
(2015/09/22)
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- Mt-tRNA components: Synthesis of (2-Thio)uridines modified with blocked glycine/taurine moieties at C-5,1
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In this paper, we discuss the usefulness of reductive amination of 5-formyl-2′,3′-O-isopropylidene(-2-thio)uridine with glycine or taurine esters in the presence of sodium triacetoxyborohydride (NaBH(OAc) 3) for the synthesis of the native mitochondrial (mt) tRNA components 5-carboxymethylaminomethyl(-2-thio)uridine (cmnm5(s2)U) and 5-taurinomethyl(-2-thio)uridine (τm5(s2)U) with a blocked amino acid function. 2-(Trimethylsilyl)ethyl and 2-(p-nitrophenyl)ethyl esters of glycine and 2-(2,4,5-trifluorophenyl)ethyl ester of taurine were selected as protection of carboxylic and sulfonic acid residues, respectively. The first synthesis of 5-formyl-2′,3′-O-isopropylidene-2-thiouridine is also reported.
- Leszczynska, Grazyna,Leonczak, Piotr,Dziergowska, Agnieszka,Malkiewicz, Andrzej
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p. 599 - 616
(2013/11/19)
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