1000389-71-8Relevant articles and documents
A practical synthesis of tris(pyrazolyl)methylaryls
Liddle, Brendan J.,Gardinier, James R.
, p. 9794 - 9797 (2007)
(Figure Presented) The preparation of three tris(pyrazolyl)toluidines from trifluoromethylaniline reagents is described that likely takes advantage of (quinoidal) resonance-stabilized activation of the C-F bonds. Subsequent transformations lead to two add
Preparation method for p-hydroxybenzoic acid
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Paragraph 0019; 0020, (2016/10/31)
The invention relates to a preparation method for p-hydroxybenzoic acid. The preparation method comprises successively adding pyrazole, 4-aminobenzotrifluoride and potassium hydroxide into dimethyl sulphoxide, dissolving, heating and refluxing for 1 h, cooling, adding water into the refluxing liquid for dissolving, adding dichloromethane, separating the liquid, extracting for three times, drying the organic phase with anhydrous magnesium sulfate, and performing column chromatography separation for obtaining 4-(tri(pyrazol-1-yl)methyl)aniline; and dropwise adding concentrated sulfuric acid into a mixed solution of 4-(tri(pyrazol-1-yl)methyl)aniline and water, dropwise adding a sodium nitrite aqueous solution under an ice bath condition with stirring, dropwise adding a sulfuric acid solution with the concentration of 15.5%, heating to 30-100 DEG C, reacting for 15 min to 2 h, naturally cooling, adding ethyl acetate and performing liquid-separation extraction for three times, performing reduced-pressure rotary evaporation, drying the organic phase with anhydrous sodium sulfate, and performing vacuum drying, so as to obtain p-hydroxybenzoic acid. The reaction synthetic route is short, reaction time is short, yield is high, and postprocessing is simple. The yield of 4-(tri(pyrazol-1-yl)methyl)aniline is about 80%, and the yield of p-hydroxybenzoic acid is about 99%.
