112704-79-7Relevant articles and documents
Synthesis method of 2-fluoro-4-halogen benzoic acid
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Paragraph 0033; 0036; 0054; 0057-0058, (2021/04/17)
The invention provides a synthesis method of 2-fluoro-4-halogen benzoic acid. The synthesis method comprises the following steps: (a) removing hydrogen from a substance shown in a formula (I) by using a lithium amide reagent or an alkyl lithium reagent (LDA, TMPLi, n-butyl lithium and the like), and reacting with trialkyl halosilane (TMSCl, TESCl, TBSCl and the like) to obtain a compound shown in a formula (II); (b) removing hydrogen from the compound represented by the formula (II) obtained in the step (a) by using a lithium amide reagent or an alkyl lithium reagent (LDA, TMPLi, n-butyl lithium and the like), and adding into dry ice/THF to react to obtain a compound represented by a formula (III); and (c) removing a trialkyl silane protecting group from the compound shown in the formula (III) obtained in the step (b) to obtain a compound shown in a formula (IV). According to the preparation method, starting raw materials, process routes and post-treatment processes are different, the raw materials are simple and easy to obtain, the cost is low, and the preparation method is suitable for laboratory small-scale preparation and industrial production.
INHIBITORS OF STEAROYL-COA DESATURASE
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, (2009/06/27)
Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, obesity.
Fluorine-flanked congested sites: Minimal, though perceptible buttressing effects on the proton mobility of arenes
Heiss, Christophe,Leroux, Frederic,Schlosser, Manfred
, p. 5242 - 5247 (2007/10/03)
(2,6-Difluorophenyl)trimethylsilane, -triethylsilane and -triisopropylsilane undergo sec-butyllithium-mediated metalation at the 3- and 4-position (ortho and meta relative to the halogen) in ratios of 99.6:0.4, 98:2 and 95:5, respectively. The steric pressure transmitted by the fluorine atoms can be increased if the trialkylsilyl group is locked up on the other side by a relatively voluminous substituent. Whereas (2,6-difluorophenyl)triethylsilane is attacked by lithium 2,2,6,6-tetramethylpiperidide under deprotonation of the 4- and 5-position in a ratio of 99.4:0.6, the proportion of "ortho"/ "meta" metalation changes to 84:16 when (2-bromo-6-fluorophenyl) triethylsilane acts as the substrate. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.