- Fluorination of methyl 3-oxopentanoate (MOP) using difluorobis(fluoroxy)methane, BDM
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Difluorobis(fluoroxy)methane, BDM, is an electrophilic fluorinating agent that is capable of affecting selective monofluorination of 1,3-dicarbonyls such as diketones and ketoesters with very high regioselectivity. For example, in highly acidic anhydrous HF (AHF) solvent, fluorination of methyl 3-oxopentanoate (MOP) with BDM provides methyl 2-fluoro-3-oxopentanoate (MFOP) with 100% conversion and 95% selectivity. In mixtures of HF and methanol, fluorination conversions and selectivity are markedly lower. In comparison, direct fluorination of MOP with dilute F2 typically affords a fluorinated product that is less pure, being contaminated with radical fluorination byproducts that are difficult to separate. Fluorination of MOP with dilute mixtures of BDM and F2 is generally more selective than using dilute F2 alone.
- Bailey III, Wade H.,Casteel Jr., William J.,Syvret, Robert G.
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- Electrophilic fluorination with N,N′-difluoro-2,2′-bipyridinium salt and elemental fluorine
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NNpm-Difluoro-22pm-bipyridiniu m bis(tetrafluoroborate) (MEC-31) was shown to be a highly reactive electrophilic fluorinating agent with the highest effective fluorine content in its class. We have developed the perfect recycled fluorination system with MEC-31 for the lower-cost industrial fluorination and for an environment. MEC-31 can be completely recycled including the counter-anion. We found the fluorination of 2-naphthol in liquid CO2 with MEC-31 in the presence of catalytic amount of NaOTf proceeded quantitatively without the generation of by-product. In the fluorination of 1,3-dicarbonyl compounds with elemental fluorine, we found the introduction method of fluorine gas would be very important in order to make a reaction efficient. As fluorination goes on, the quantity of 1,3-dicarbonyl compounds of the starting material is reduced gradually, and therefore the quantity of fluorine must be reduced by the method to control the flow rate or the concentration of fluorine gas diluted with nitrogen, together the fluorination to proceed efficiently.
- Adachi, Kenji,Ohira, Yutaka,Tomizawa, Ginjiro,Ishihara, Sumi,Oishi, Satoshi
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- Novel bi-cyclic or tri-cyclic heterocyclic compound
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The present invention provides novel bi-cyclic or tri-cyclic compound represented by formula (I) or pharmaceutical acceptable salt thereof, [wherein, ring A is an aromatic group which may be substituted, one of X1 and X2 is a carbon atom, and another is a nitrogen atom, X3 is a nitrogen atom or CR2, X4 is a nitrogen atom or CR3, X5 is a sulfur atom or -CH=CH-, Z1 is an oxygen atom, -C(R6)(R7)-, -NH-, -C(R6)(R7)-NH-, -NH-C(R6)(R7)-, -C(R6)(R7)-O-, -O-C(R6)(R7)- or a single bone, one of Z2 and Z3 is CH and another one is a nitrogen atom, or both are nitrogen atoms, the other symbols are same as those defined in the specification.]
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Paragraph 5047 - 5049
(2016/10/07)
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- One-pot synthesis of 3,5-disubstituted and polysubstituted phenols from acyclic precursors
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A new strategy for the synthesis of 3,5-disubstituted phenols is established through one-pot Robinson annulation of α,β-unsaturated ketones with α-fluoro-β-ketoesters followed by in situ dehydrofluorination and tautomerization. This method has been extended to the synthesis of polysubstituted phenols and applied in the preparation of biologically active compounds.
- Qian, Jinlong,Yi, Wenbin,Huang, Xin,Miao, Yongbo,Zhang, Junkai,Cai, Chun,Zhang, Wei
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supporting information
p. 1090 - 1093
(2015/03/14)
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- An original synthesis of highly ordered organosilica with a high content of thiol groups
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Well ordered bridged organosilica highly functionalised with disulfide groups were obtained by self-assembly of α,ω-bis(trimethoxysilyl) alkyldisulfide under hydrophilic conditions; the reduction of disulfide cores to SH groups gave rise to material having a high mercury ion adsorption capacity. The Royal Society of Chemistry 2006.
- Alauzun, Johan,Mehdi, Ahmad,Reye, Catherine,Corriu, Robert J. P.
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p. 347 - 349
(2008/02/08)
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- METHOD OF PURIFYING AND SEPARATING 2-FLUORO-3-OXOALKYLCARBOXYLIC ACID ESTER
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The present invention concerns a method for purifying/separating a 2-fluoro-3-oxoalkylcarboxylic acid ester from a reaction mixture resulting from the fluorination of a 3-oxoalkylcarboxylic acid ester. The method involves depleting the reaction mixture of a hydrogen fluoride byproduct; and subsequently, separating the 2-fluoro-3-oxoalkylcarboxylic acid ester by distillation. The 2-fluoro-3-oxoalkylcarboxylic acid ester obtained by the method of the invention is highly pure and is thus suitable for use as an intermediate for the production of pharmacological products or agricultural chemicals.
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Page column 5
(2008/06/13)
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- PROCESS FOR PRODUCING 2-FLUORO-3-OXOALKYLCARBOXYLIC ACID ESTER
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A process for producing a 2-fluoro-3-oxoalkylcarboxylic acid ester by fluorinating 3-oxoalkylcarboxylic acid ester with a fluorine gas is provided. The process is characterized in that the concentration of 3-oxoalkylcarboxylic acid ester in the reaction mixture for fluorination is maintained at 3wt% or higher. Also provided is a process for purifying 2-fluoro-3-oxoalkylcarboxylic acid ester characterized in that 2-fluoro-3-oxoalkylcarboxylic acid ester is produced at high yield and with less impurities by washing fluorinated 3-oxoalkylcarboxylic acid ester with 3 or more times as much water as the amount of reaction mixture. According to the processes of the present invention, not only is the generation of unwanted by-products minimized, but fluorinated 3-oxoalkylcarboxylic acid ester can be purified in an efficient manner. Thus, the present invention permits efficient production of considerably pure 2-fluoro-3-oxoalkylcarboxylic acid ester, a useful intermediate material in the production of various medical and agricultural agents.
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Page/Page column 6-8
(2008/06/13)
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- High purity preparation of fluorinated 1,3-dicarbonyls using BDM (bis-fluoroxydifluoromethane)
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A process for providing an α-fluorinated-β-dicarbonyl includes electrophilically fluorinating a β-dicarbonyl with bis-fluoroxydifluoromethane in the presence of an acid to provide the α-monofluorinated-β-dicarbonyl. The acid is preferably hydrofluoric acid. Preferred β-dicarbonyls include methyl-3-oxopentanoate and ethyl-4,4,4-trifluoroacetoacetate. The process can limit radical impurity byproducts to no more than 4% in some cases, and less than 0.5% in other cases. Theoretical yields of 95% α-monofluorinated-β-dicarbonyl are possible in some cases.
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