38841-54-2Relevant articles and documents
Synthesis and structure of novel 6-(pyrazol-1-yl)-4-methyl-1H-pyrazolo[3,4- b]pyridin-3-ol derivatives
Wu, Ai Qun,Tang, Yong,Huang, Su-Yu,Shen, Li-Qun
, p. 239 - 247 (2014)
New 6-(pyrazol-1-yl)pyrazolo[3,4-b]pyridin-3-ol compounds were synthesized by cyclization reaction from 2,6-dichloro-4-methylnicotinonitrile. Their derivatives exist as the 3-hydroxy tautomer. The structure of the compound 1a of one of the resulting compounds was studied in detail by X-ray diffraction.
OXADIAZOLE TRANSIENT RECEPTOR POTENTIAL CHANNEL INHIBITORS
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, (2019/09/30)
The invention relates to compounds of formula I: and pharmaceutically acceptable salts thereof wherein A, X, R1, R4 and n are as defined herein. In addition, the present invention relates to methods of manufacturing and methods of using the compounds of formula I as well as pharmaceutical compositions containing such compounds. The compounds may be useful in treating diseases and conditions mediated by TRPA1, such as pain.
Preparation method for nevirapine intermediate
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Paragraph 0014; 0035; 0045; 0055; 0059; 0064-0065, (2019/01/14)
The invention provides a preparation method for a nevirapine intermediate. The preparation method comprises: performing a cyclization reaction of ammonia water, methyl cyanoacetate and methyl acetoacetate to form a compound hydroxyl: 2,6-dihydroxy-3-cyano-4-methylpyridine; adding triethylamine dropwise, introducing chlorine gas at the temperature until the reaction is complete, and obtaining 2,6-dichloro-3-cyano-4-methylpyridine; adding concentrated sulfuric acid, heating to 120 DEG C to react for 3-5 h, and then cooling to 60 DEG C; adding water to perform hydrolysis reaction, and obtaining 2,6-dichloro-3-amido-4-methylpyridine; adding a degradation reagent sodium hypochlorite, and obtaining a nevirapine intermediate 2,6-dichloro-3-amino-4- methylpyridine by Hofmann reaction. According tothe preparation method, commonly used phosphorus oxychloride is replaced with the directly introduced chlorine gas, which solves the problems that the wastewater content is too high, it is difficultto perform treatment and the odor of phosphorus oxychloride is bad, and the one-time yield of the product is 90.1%.