- Synthesis method of dialkyl 2,2-difluorodicarboxylate
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The invention discloses a synthesis method of dialkyl 2,2-difluorodicarboxylate. The synthesis method comprises the following steps: (A) directly carrying out fluorination on 2-cyclene-1-one shown ina formula I, or firstly carrying out chlorination and then carrying out fluorination on the 2-cyclene-1-one so as to obtain 3,3-difluorocycloolefin shown in a formula II; (B) simultaneously oxidizingand esterifying the 3,3-difluorocycloolefin shown in the formula II, or firstly oxidizing and then esterifying the 3,3-difluorocycloolefin so as to obtain the dialkyl 2,2-difluorodicarboxylate shown in a formula III, wherein a chlorinating agent and a fluorinating agent which are used in the step of firstly carrying out chlorination and then carrying out fluorination are respectively oxalyl chloride and triethylamine trihydrofluoride; a reaction system used in the step of simultaneously oxidizing and esterifying is ozone gas/sodium ethoxide, and the reaction temperature is -75 to -15 DEG C. The synthesis method has the advantages of novel synthetic route, less pollution to the environment, lower production cost, simple reaction conditions, easy operation, higher reaction safety and fewer side reactions, can obtain higher reaction yield especially by selecting proper reaction conditions, and has the highest total yield of 82% or above, thus being suitable for industrial production.
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Paragraph 0040-0044
(2018/07/15)
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- Through the use of water or more acid as the additive model mckail addition reaction of the method of preparation of the compound
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The present invention relates to a novel method for preparing a compound represented by chemical formula 1 using water or various acids as an additive in a Michael addition reaction of a Michael receptor represented by chemical formula 2 and a compound re
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Paragraph 0060; 0061; 0062; 0063; 0064
(2016/10/07)
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- PRODUCTION METHOD OF INTERMEDIATE COMPOUND FOR SYNTHESIZING MEDICAMENT
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The present invention relates to a novel method for preparing a compound of formula (2) as the intermediate, which can be effectively used for preparation of a compound of formula (1) exhibiting good inhibitory activity against dipeptidyl peptidase IV enz
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Paragraph 0098; 0099; 0100
(2013/07/05)
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- Highly Improved copper-mediated michael addition of ethyl bromodifluoroacetate in the presence of protic additive
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Copper-mediated Michael addition of ethyl bromodifluoroacetate to Michael acceptors is accompanied by the formation of a substantial amount of byproducts. Elucidation of their structure hinted the cause of their formation, from which we discovered a highl
- Kim, Bong Chan,Park, Aeri,An, Ji Eun,Lee, Hee Bong,Shin, Hyunik,Lee, Won
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p. 3165 - 3170,6
(2020/08/20)
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- PRODUCTION METHOD OF INTERMEDIATE COMPOUND FOR SYNTHESIZING MEDICAMENT
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The present invention relates to a novel method for preparing a compound of formula (2) as the intermediate, which can be effectively used for preparation of a compound of formula (1) exhibiting good inhibitory activity against dipeptidyl peptidase IV enz
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Page/Page column 11
(2012/03/26)
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- DIPEPTIDYL PEPTIDASE-IV INHIBITING COMPOUNDS, METHODS OF PREPARING THE SAME, AND PHARMACEUTICAL COMPOSITIONS CONTAINING THE SAME AS ACTIVE AGENT
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Disclosed herein are novel compounds of Formula (1) as defined in the specification having excellent inhibitory activity against dipeptidyl peptidase-IV (DPP-IV), methods of preparing the same and pharmaceutical compositions comprising the same as an active agent.
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Page/Page column 41-42
(2009/07/25)
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- Certain fluorine substituted PGI2 compounds
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Prostaglandin and prostacyclin compounds which are fluorine substituted in any one or more of the following positions, 4,4; 7,7; 10,10; and 5.
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