- Synthesis of cresotic acids by carboxylation of cresols with sodium ethyl carbonate
-
Carboxylation of o-cresol, m-cresol, and p-cresol with sodium ethyl carbonate (SEC) proceeds regioselectively with the formation of cresotic acids: 2-hydroxy-3-methylbenzoic acid, 2-hydroxy-4-methylbenzoic acid, and 2-hydroxy-5-methylbenzoic acid, respectively. Optimal conditions for conducting the process have been found to be as follows: the reactants ratio of [cresol]: [sodium ethyl carbonate] = (1.5–2): 1, T = 180–185°C, PCO2 = 10 atm, and t = 6–7 h. Simple and convenient methods for the synthesis of cresotic acids, which can be used for their industrial manufacturing, have been developed.
- Suerbaev, Kh. A.,Chepaikin,Kudaibergenov, N. Zh.,Zhaksylykova, G. Zh.
-
-
Read Online
- Palladium-catalyzed ortho-C-H hydroxylation of benzoic acids
-
A simple Pd(OAc)2 catalyzed ortho-hydroxylation of benzoic acids using TBHP as the sole oxidant has been explored. This protocol features relatively broad substrate scope and operational simplicity. The compatibility of ortho-substituted substrates is an effective complement to the previous ortho-hydroxylation reaction.
- Luo, Feihua,He, Shuhua,Gou, Quan,Chen, Jinyang,Zhang, mingzhong
-
-
- Carboxylation of Phenols with CO2 at Atmospheric Pressure
-
A convenient and efficient method for the ortho-carboxylation of phenols under atmospheric CO2 pressure has been developed. This method provides an alternative to the previously reported Kolbe-Schmitt method, which requires very high pressures of CO2. The addition of a trisubstituted phenol has proved essential for the successful carboxylation of phenols with CO2 at standard atmospheric pressure, allowing the efficient preparation of a broad variety of salicylic acids.
- Luo, Junfei,Preciado, Sara,Xie, Pan,Larrosa, Igor
-
supporting information
p. 6798 - 6802
(2016/05/11)
-
- General method for the synthesis of salicylic acids from phenols through palladium-catalyzed silanol-directed C-H carboxylation
-
A silanol-directed, palladium-catalyzed C-H carboxylation reaction of phenols to give salicylic acids has been developed. This method features high efficiency and selectivity, and excellent functional-group tolerance. The generality of this method was demonstrated by the carboxylation of estrone and by the synthesis of an unsymmetrically o,o′-disubstituted phenolic compound through two sequential C-H functionalization processes.
- Wang, Yang,Gevorgyan, Vladimir
-
p. 2255 - 2259
(2015/02/19)
-
- Regioselective ortho-carboxylation of phenols catalyzed by benzoic acid decarboxylases: A biocatalytic equivalent to the Kolbe-Schmitt reaction
-
The enzyme catalyzed carboxylation of electron-rich phenol derivatives employing recombinant benzoic acid decarboxylases at the expense of bicarbonate as CO2 source is reported. In contrast to the classic Kolbe-Schmitt reaction, the biocatalytic equivalent proceeded in a highly regioselective fashion exclusively at the ortho-position of the phenolic directing group in up to 80% conversion. Several enzymes were identified, which displayed a remarkably broad substrate scope encompassing alkyl, alkoxy, halo and amino- functionalities. Based on the crystal structure and molecular docking simulations, a mechanistic proposal for 2,6-dihydroxybenzoic acid decarboxylase is presented.
- Wuensch, Christiane,Gross, Johannes,Steinkellner, Georg,Lyskowski, Andrzej,Gruber, Karl,Glueck, Silvia M.,Faber, Kurt
-
p. 9673 - 9679
(2014/03/21)
-
- PD(II)-CATALYZED HYDROXYLATION OF ARENES WITH O2 OR AIR
-
Pd (II) -catalyzed ortho-hydroxylat ion of variously substituted aromatic carboxylic acids under O2 or air is achieved under non-acidic conditions. Extensive labeling studies support a direct oxygenation of aryl C-H bonds with molecular oxygen.
- -
-
Page/Page column 14
(2011/04/24)
-
- Pd(II)-catalyzed hydroxylation of arenes with 1 atm of O2 or air
-
(Chemical Equation Presented) Pd(II)-catalyzed ortho-hydroxylation of variously substituted benzoic acids under 1 atm of O2 or air is achieved under nonacidic conditions. Extensive labeling studies support a direct oxygenation of aryl C-H bonds with molecular oxygen.
- Zhang, Yang-Hui,Yu, Jin-Quan
-
supporting information; experimental part
p. 14654 - 14655
(2010/01/06)
-
- Process for the synthesis of hydroxy aromatic acids
-
Hydroxy aromatic acids are produced in high yields and high purity (>95%) from halogenated aromatic acids in a reaction mixture containing a copper source and a ligand that coordinates to copper.
- -
-
Page/Page column 21
(2008/06/13)
-
- COMPOSITIONS AND METHODS FOR THE TREATMENT OF IMMUNOMEDIATED INFLAMMATORY DISORDERS
-
Compositions and methods for the prevention and treatment of immunomediated inflammatory disorders, especially for those disorders associated with the respiratory tract, are provided. More particularly, a tryptase inhibitor, typically a hydroxyaroyl or hydroxyheteroaroyl substituted dipeptide, is administered. Also provided by this invention are pharmaceutical compositions, typically aerosol or topical, as well as aerosol devices for administering these compositions intranasally.
- -
-
-
- External preparation for skin
-
An external preparing for skin comprising one or more than two types of 2-hydroxy benzoic acid derivative and/or salt thereof represented by the following formula: STR1 wherein R is an alkoxy group or alkyl group in the formula. The external preparation for the skin according to the present invention has a suppression effect on melanine generation by inhibition of tyrosinase activity. Accordingly, an excellent bleaching effect based upon the suppression of chromatosis and a high degree of safety can be obtained.
- -
-
-
- Metal Template ortho-Acylation of Phenols. Direct Synthesis of Salicylic Acid Chlorides and Derivatives
-
A direct synthesis of salicylic acid chlorides is achieved via "metal-driven" intracomplex acylation of bromomagnesium and aluminum phenoxides with phosgene.Salicylic acids 5 and some derivatives 6, 7 can be obtained by quenching the reaction mixture with convenient reagents.Moreover the reaction of lithium phenylacetylide with 3 provides a new convenient approach to ortho-hydroxyaryl alkynyl ketones like 8.The oriented complex 2, involving the metal phenoxide and phosgene is proposed to account for the ortho-regioselective control of the reaction.
- Sartori, Giovanni,Casnati, Giuseppe,Bigi, Franca,Bonini, Giovanni
-
p. 763 - 766
(2007/10/02)
-
- Benzamide derivatives
-
Benzamide derivatives of the formula:- STR1 wherein R1 represents a fluorine, chlorine or bromine atom, or an alkyl, alkoxy, alkylthio, alkylsulphonyl, alkanoylamino, alkylamino or alkylsulphamoyl group, each such group containing from 1 to 6 carbon atoms, a dialkylsulphamoyl, dialkylamino or dialkylcarbamoyl group (wherein the two alkyl groups may be the same or different and each contains from 1 to 4 carbon atoms), an alkanoyl, alkoxycarbonyl, alkoxycarbonylamino or alkylcarbamoyl group containing from 2 to 6 carbon atoms, or a hydroxy, formyl, nitro, trifluoromethyl, aryl, benzyloxycarbonylamino, amino, sulphamoyl, cyano, tetrazol-5-yl, carboxy, carbamoyl or aroyl group, and n represents an integer 1, 2 or 3, are new compounds possessing pharmacological properties, in particular properties of value in the treatment of respiratory disorders manifested by the interaction of tissue-fixed antibodies with specific antigens.
- -
-
-
