320-94-5Relevant articles and documents
2-nitro-4-trifluoromethyl-benzoic acid and preparation method of isomer thereof
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Paragraph 0037; 0039; 0041; 0043; 0045; 0047; 0049-0055, (2018/10/19)
The invention discloses a 2-nitro-4-trifluoromethyl-benzoic acid and a preparation method of an isomer thereof, belongs to the technical field of organic synthesis, and solves the problems that in theprior art, raw materials for preparing a 2-nitro-4-trifluoromethyl-benzoic acid and the isomer thereof are expensive and the yield is slightly low. In order to solve the problems, the invention provides the 2-nitro-4-trifluoromethyl-benzoic acid and the preparation method of the isomer thereof. The preparation method comprises the following steps: with 4-(trifluoromethyl)benzonitrile as a raw material, performing a one-step reaction under the effect of a nitrating agent to obtain the 2-nitro-4-trifluoromethyl-benzoic acid and a 3-nitro-4-trifluoromethyl-benzoic acid. The preparation method has the advantages that the 2-nitro-4-trifluoromethyl-benzoic acid and the isomer thereof can be obtained only through the one-step reaction, the operation is simple and convenient, the reaction steps are short, the yield is high, and the 2-nitro-4-trifluoromethyl-benzoic acid and the isomer thereof are suitable for industrialized production.
Preparative method for carboxylic acids
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Paragraph 0030, (2018/02/03)
A preparative method for carboxylic acids is disclosed in the present invention. The method is characterized in that: compounds (II) are reacted in the presence of hydrogen peroxide and base to produce target products (I), as represented by the following reaction scheme: wherein R1 is aryl, pyridyl, pyrimidyl, pyridazinyl, pyrazinyl, benzothienyl, benzofuranyl, quinolinyl, isoquinolinyl, thiadiazolyl, C1-6 alkyl, C3-6 cycloalkyl, C2-6 alkenyl, C2-6 alkynyl and hydrogen; R2 is alkoxycarbonyl, alkylaminocarbonyl, aminocarbonyl, alkylthiolcarbonyl, cyano, sulfonyl, sulfinyl, carbonyl, aldehyde, carboxyl, nitro, alkyl and hydrogen; R3 is alkoxycarbonyl, alkyl amido carbonyl, aminocarbonyl, cyano, sulfonyl, sulfinyl, carbonyl, carboxyl and nitro. The present invention has the following main benefits: cheap and readily available starting materials, safe processes, high yield, good quality, which facilitates industrial production.
1H NMR, 13C NMR, and computational DFT studies of the structure of 2-acylcyclohexane-1,3-diones and their alkali metal salts in solution
Szczecinski, Przemyslaw,Gryff-Keller, Adam,Molchanov, Sergey
, p. 4636 - 4641 (2007/10/03)
1H and 13C NMR spectra of 2-acyl-substituted cyclohexane-1,3-diones (acyl = formyl, 1; 2-nitrobenzoyl, 2; 2-nitro-4-trifluoromethylbenzoyl, 3) and lithium sodium and potassium salts of 1 have been measured. The compound 3, known as NTBC, is a life-saving medicine applied in tyrosinemia type I. The optimum molecular structures of the investigated objects in solutions have been found using the DFT method with B3LYP functional and 6-31G** and/or 6-311G(2d,p) basis set. The theoretical values of the NMR parameters of the investigated compounds have been calculated using GIAO DFT B3LYP/6-311G(2d,p) method. The theoretical data obtained for compounds 1-3 have been exploited to interpret their experimental NMR spectra in terms of the equilibrium between different tautomers. It has been found that for these triketones an endo-tautomer prevails. The differences in NMR spectra of the salts of 1 can be rationalized taking into account the size of the cation and the degree of salt dissociation. It seems that in DMSO solution the lithium salt exists mainly as an ion pair stabilized by the chelation of a lithium cation with two oxygen atoms. The activation free energy the of formyl group rotation for this salt has been estimated to be 51.5 kJ/mol. The obtained results suggest that in all the investigated objects, including the free enolate ions, all atoms directly bonded to the carbonyl carbons lie near the same plane. Some observations concerning the chemical shift changes could indicate strong solvation of the anion of 1 by water molecules. Implications of the results obtained in this work for the inhibition mechanism of (4-hydroxyphenyl) pyruvate dioxygenase by NTBC are commented upon.