- Synthesis method of 3-chloro-2,4-difluorobenzoic acid
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The invention relates to a synthesis method of 3-chloro-2,4-difluorobenzoic acid. The method comprises: taking 1,2,3-trichlorobenzene and N-bromosuccinimide to react, taking CuCN and 1-bromo-2,3,4-trichlorobenzene to react, taking the 1-bromo-2,3,4-trichlorobenzene and KF to react and taking 3-chloro-2,4-difluorobenzonitrile and sulfuric acid to react, so as to form the 3-chloro-2,4-difluorobenzoic acid. According to the synthesis method, synthesis reaction conditions are that a reaction is carried out at normal pressure and reaction temperature fluctuates between 0 and 250 DEG C; the obtained finished product is a light yellow powdery solid and the content is more than or equal to 99.0 percent; the total mol yield of the 3-chloro-2,4-difluorobenzoic acid can reach 61.5 percent; whole reaction conditions are moderate and the method is convenient to operate and control; pressure of waste gas, waste water and waste residues is relatively low so that industrial production is facilitated.
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Paragraph 0023; 0028; 0029
(2017/02/17)
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- THE USE OF SELECTIVE P2X7 RECEPTOR ANTAGONISTS
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The present invention relates to the use of selective P2X7 receptor antagonists of formula (I), or a pharmaceutically acceptable salt or prodrug thereof wherein D, R1 and R2 are as defined in claim 1, for the treatment of neuropathic pain, chronic inflammatory pain, inflammation, neurodegeneration and for promoting neuroregeneration.
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Page/Page column 54
(2008/06/13)
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