455-86-7Relevant articles and documents
New method for non-metal catalytic oxidation synthesis of substituted benzoic acid compound
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Paragraph 0059; 0060; 0061; 0062, (2018/01/11)
The invention discloses a method for synthesis of a substituted benzoic acid compound, a Wittig reagent and hydrogen peroxide as raw materials are reacted by heating in an organic solvent at reaction temperature of room temperature or 50 DEG C, the reaction formula is as shown in the specification, in the formula, Ar is an aromatic ring substituent, X is an unsaturated ester substituent or an aromatic ring substituent. The method has the following beneficial effects: (1) the method has the advantages of simple operation, wide substrate application range, high yield, friendliness to the environment; (2) the Wittig reagent is simple in preparation, the raw materials are cheap, the Wittig reagent which is not participated in the reaction can also be recycled by recrystallization; (3) the reaction conditions of the Wittig reagent and the hydrogen peroxide are mild, and the post treatment is simple, the method is green and environmentally-friendly and is suitable for industrial enlargement; and (4) by-product triphenylphosphine oxide is also recyclable, is an important chemical raw material and can be applied as organic synthesis intermediates, pharmaceutical intermediates, catalysts and extractants.
Oxidative cleavage of α-sulfonyl ketones to carboxylic acids with Ce(NH4)2(NO3)6
Chang, Meng-Yang,Tsai, Chung-Yu
supporting information, p. 5548 - 5550 (2014/12/11)
Tandem oxidative cleavage of α-sulfonyl arylketones 2 with the combination of Ce(NH4)2(NO3)6 and O2 in MeCN afforded carboxylic acids 3 in moderate to good yields. The plausible reaction mechanism has
Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information, p. 8986 - 8998,13 (2012/12/12)
Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
Novel 2,2,6,6-tetramethylpiperidine 1-oxyl-iodobenzene hybrid catalyst for oxidation of primary alcohols to carboxylic acids
Yakura, Takayuki,Ozono, Ayaka
experimental part, p. 855 - 859 (2011/06/26)
Novel bifunctional hybrid-type catalysts bearing 2,2,6,6- tetramethylpiperidine-1-oxyl (TEMPO) and iodobenzene moieties (1a and 1b) were developed and used for the environmentally benign oxidation of primary alcohols to carboxylic acids. Reaction of primary alcohols 2 with a catalytic amount of 1 in the presence of peracetic acid as a co-oxidant under mild conditions gave the corresponding carboxylic acids 3 in excellent yields.
Kinetic and chemical characterization of aldehyde oxidation by fungal aryl-alcohol oxidase
Ferreira, Patricia,Hernandez-Ortega, Aitor,Herguedas, Beatriz,Rencoret, Jorge,Gutierrez, Ana,Martinez, Maria Jesus,Jimenez-Barbero, Jesus,Medina, Milagros,Martinez, Angel T.
scheme or table, p. 585 - 593 (2011/02/24)
Fungal AAO (aryl-alcohol oxidase) provides H2O2 for lignin biodegradation. AAO is active on benzyl alcohols that are oxidized to aldehydes. However, during oxidation of some alcohols, AAO forms more than a stoichiometric number of H2O2 molecules with respect to the amount of aldehyde detected due to a double reaction that involves aryl-aldehyde oxidase activity. The latter reactionwas investigated using different benzylic aldehydes, whose oxidation to acids was demonstrated by GC-MS. The steady- and presteady state kinetic constants, together with the chromatographic results, revealed that the presence of substrate electron-withdrawing or electron-donating substituents had a strong influence on activity; the highest activity was with p-nitrobenzaldehyde and halogenated aldehydes and the lowest with methoxylated aldehydes. Moreover, activity was correlated to the aldehyde hydration rates estimated by 1H-NMR. These findings, together with the absence in the AAO active site of a residue able to drive oxidation via an aldehyde thiohemiacetal, suggested that oxidation mainly proceeds via the gem-diol species. The reaction mechanism (with a solvent isotope effect, 2H2O kred, of approx. 1.5)would be analogous to that described for alcohols, the reductive half-reaction involving concerted hydride transfer from the a-carbon and proton abstraction from one of the gem-diol hydroxy groups by a base. The existence of two steps of opposite polar requirements (hydration and hydride transfer) explains some aspects of aldehyde oxidation by AAO. Site-directed mutagenesis identified two histidine residues strongly involved in gem-diol oxidation and, unexpectedly, suggested that an active-site tyrosine residue could facilitate the oxidation of some aldehydes that show no detectable hydration. Double alcohol and aldehyde oxidase activities of AAO would contribute to H2O2 supply by the enzyme. The Authors Journal compilation
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.
Preparation of aromatic and heteroaromatic carboxylic acids by catalytic ozonolysis
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Page/Page column 4, (2008/06/13)
A process for catalytically oxidizing alkylaromatic compounds of the formula (I) Ar—CH2—R where Ar is an optionally substituted, aromatic or heteroaromatic 5-membered or 6-membered ring or a ring system having up to 20 carbon atoms where Ar may optionally be fused to a C1-C6-alkyl group in which up to 2 carbon atoms may be replaced by a heteroatom, and R is hydrogen, phenyl, benzyl or heteroaryl, where the phenyl, benzyl or heteroaryl radicals may also be joined to Ar by a bridge, or R together with Ar forms an optionally substituted ring system which may contain one or more optionally substituted heteroatoms, to the corresponding aromatic or heteroaromatic carboxylic acids in a solvent with ozone in the presence of a transition metal catalyst and optionally in the presence of an acid at a temperature between ?70° C. and 110° C. to the corresponding carboxylic acid.
Fragmentation of radical anions of polyfluorinated benzoates
Konovalov, Valery V.,Laev, Sergey S.,Beregovaya, Irina V.,Shchegoleva, Lyudmila N.,Shteingarts, Vitalij D.,Tsvetkov, Yuri D.,Bilkis, Itzhak
, p. 352 - 361 (2007/10/03)
A comprehensive study of the symmetry forbidden fragmentation of short-lived radical anions (RAs) has been undertaken for the complete set of polyfluorinated benzoates (C6FnH5-nCO22, n = 1-5). The decay rate constants (kc) of RAs have been determined in aqueous alkaline solution (pH 13.4) by electron photoinjection (EPI) from mercury electrodes and were found to increase dramatically from ≤3 × 103 s-1 (3-F - C6H4CO2-) to (1.2 ± 0.8) × 109 s-1 (C6F5CO2-). The regioselectivity of C-F bond cleavage in the RA fragmentation has been revealed by structure assignment of reduction products of the polyfluorinated benzoic acids by Na, K, and Zn in liquid NH3, as well as by Zn in aqueous NH3 and aqueous alkaline solutions. The kc values depend on the position of the cleaved fluorine to the CO2- group generally in the order para > ortho > meta, and to sharply increase if adjacent fluorine atoms are present. The observed trends reveal that the kinetics of the RA fragmentation reaction is not controlled by the reaction thermodynamics. Semiempirical UHF/INDO calculations, the validity of which has been confirmed by ab initio ROHF/6-31+G calculations, were done to rationalize the observed trends. The reaction transition state (TS) was considered to arise from the RA's and 2*states crossing avoided due to out-of-plane deviation of the cleaving C-F bond. The satisfactory linear correlation (R = 0.96) between the model reaction energy barrier Ea and log kc has been achieved with modeling the local solvation of the CO2- group by its protonation.
Synthesis and mesomorphic properties of some fluoro-substituted benzoates
Yang,Tang,Gong,Wen
, p. 153 - 165 (2007/10/03)
Several series of fluoro-substituted benzoate liquid crystals have been synthesized. The results showed that the SmA phase is enhanced with the increasing of the degree of fluoro-substitution on the para- and meta-position of the terminal phenyl groups. And the molecules which have same molecular structural formula show nearly the same melting points. It is also discussed about the effect of the ester bond's direction on the mesomorphic properties.
Rat hepatic microsomal aldehyde dehydrogenase. Identification of 3- and 4-substituted aromatic aldehydes as substrates of the enzyme
Martini, Robert,Murray, Michael
, p. 268 - 276 (2007/10/03)
The rat hepatic microsomal aldehyde dehydrogenase (mALDH) metabolizes aliphatic and aromatic aldehydes to the corresponding acids with NAD as the optimal cofactor. However, dehydrogenation of the aliphatic compounds is substantially more efficient. In the present study, a series of aromatic aldehydes was evaluated as substrates of the purified mALDH so that the physicochemical factors that contribute to substrate affinity could be evaluated. Substitution of the aromatic system in the 3- and 4-positions produced relatively good substrates, but 2-substituted congeners did not undergo dehydrogenation. However, aldehydes with hydrophilic substituents in the 3- or 4-positions and those with extremely bulky substituents at both positions (e.g., 3,4-dibenzyloxy) were also poor substrates for the enzyme and dehydrogenation was undetectable. A quantitative structure-activity relationship was determined that related the logarithm of the Michaelis constants for 27 substituted aromatic aldehydes with the zero-order connectivity function of the molecule (0χ), the shapes of the 3-and 4-substituents (κ), and the electronic nature of the 4-substituent (σ). In this equation, 81% of the data variance was explained. From a consideration of the dimensions of 3-phenoxybenzaldehyde, which was a relatively good substrate, the mALDH possesses a narrow cleft within the active site that is at least 7.5 A wide and extends at least 12 A from the the catalytic residue (probably cysteine). Previously established relationships between connectivity functions and molecular polarizability suggest that dipolar interactions within the active site, as well as dispersion forces, may play a role in substrate specificity. Although optimal shapes for carbocyclic substituents were not provided by the analysis, the unfavorable effect on dehydrogenation from hydrophilic and large substituents suggests that the active site of the mALDH is relatively rigid and that the orientation of the substrate in relation to the catalytic cysteine and the cofactor binding site is critical.
