- Production process of cyclohexanecarboxylic acid
-
The invention discloses a production process of cyclohexanecarboxylic acid and belongs to the field of chemical synthesis. Cyclohexene oxide is used herein as a starting material to react with carbondioxide, Mg powder and TMSCl (trimethylsilyl chloride); Pd/C catalytic hydrogenation is performed in the presence of an acid to obtain the cyclohexanecarboxylic acid. The production process has good safety and good operational simplicity and is suitable for industrial production.
- -
-
Paragraph 0018; 0023; 0024
(2018/09/08)
-
- Degradation of a model naphthenic acid, cyclohexanoic acid, by vacuum UV (172 nm) and UV (254 nm)/H2O2
-
The mechanism of hydroxyl radical initiated degradation of a typical oil sands process water (OSPW) alicyclic carboxylic acid was studied using cyclohexanoic acid (CHA) as a model compound. By use of vacuum ultraviolet irradiation (VUV, 172 nm) and ultraviolet irradiation in the presence of hydrogen peroxide UV(254 nm)/H2O2, it was established that CHA undergoes degradation through a peroxyl radical. In both processes the decay of the peroxyl radical leads predominantly to the formation of 4-oxo-CHA, and minor amounts of hydroxy-CHA (detected only in UV/H2O 2). In UV/H2O2, additional 4-oxo-CHA may also have been formed by direct reaction of the oxyl radical with H-O 2. The oxyl radical can be formed during decay of the peroxyl-CHA radical or reaction of hydroxy-CHA with hydroxyl radical. Oxo- and hydroxy-CHA further degraded to various dihydroxy-CHAs. Scission of the cyclohexane ring was also observed, on the basis of the observation of acyclic byproducts including heptadioic acid and various short-chain carboxylic acids. Overall, the hydroxyl radical induced degradation of CHA proceeded through several steps, involving more than one hydroxyl radical reaction, thus efficiency of the UV/H 2O2 reaction will depend on the rate of generation of hydroxyl radical throughout the process. In real applications to OSPW, concentrations of H2O2 will need to be carefully optimized and the environmental fate and effects of the various degradation products of naphthenic acids considered.
- Drzewicz, Przemyslaw,Afzal, Atefeh,El-Din, Mohamed Gamal,Martin, Jonathan W.
-
experimental part
p. 12067 - 12074
(2011/02/27)
-
- Oxidative decarboxylation of cyclohexane monocarboxylic acid as a degenerate branching chain reaction II. Mechanism
-
Based on the experimental results obtained studying the oxidative decarboxylation of cyclohexane monocarboxylic acid and published earlier, a mechanism is suggested, according to which in the thermal oxidation two main chain carrier radicals exist: tertiary and secondary peroxy radicals yielding cyclohexanone as well as hydroxy and keto acids in parallel reaction sequences. Carbon dioxide is formed in both pathways independently. The corresponding hydroperoxide molecules, formed during oxidation, decompose partly into radicals and partly into molecules resulting in degenerate branching and chemiluminescence phenomena, respectively. The rate determining termination is the cross combination process between secondary and tertiary peroxy radicals. The combinatorial generation of the mechanism of the thermal process and its reduction enabled the construction of the sequence network of the formation of products indicating that the primary attack of the hydrogen abstraction (secondary or tertiary) determines the product distribution.
- Heberger,Keszler,Vidoczy,Gal,Cotarca,Delogu
-
p. 1303 - 1307
(2007/10/02)
-
- Chemoselective Enzymatic Hydrolysis of Aliphatic and Alicyclic Nitriles
-
Mild and selective hydrolysis of aliphatic and alicycic nitriles leading to carboxylic acids and amides was achieved under neutral conditions by an immobilized enzyme preparation from Rhodococcus sp.This method is particularly useful for the transformation of compounds containing other acid- or basesensitive groups.
- Raadt, Anna de,Klempier, Norbert,Faber, Kurt,Griengl, Herfried
-
p. 137 - 140
(2007/10/02)
-
- Selective transformation of nitriles into amides and carboxylic acids by an immobilized nitrilase
-
Using an immobilized nitrilase from Rhodococcus sp. mild and selective hydrolysis of nitriles can be achieved even in the presence of acid or base sensitive groups under neutral conditions. This method is applicable to a broad range of substrates as exemplified by aliphatic, alicyclic, heterocyclic and carbohydrate type nitriles.
- Klempier,De Raadt,Faber,Grieng
-
p. 341 - 344
(2007/10/02)
-
- Reduction of Substituted Δ2-Isoxazolines. Synthesis of β-Hydroxy Acid Derivatives
-
Three separate methods are reported for the formation of β-hydroxy acid derivatives from readily available substituted Δ2-isoxazolines.Cycloaddition of 2,2-dimethylpropanenitrile oxide with a variety of olefins followed by reductive cleavage produces α '-tert-butyl β-hydroxy ketones.These are cleaved to β-hydroxy tert-butyl esters by Baeyer-Villiger oxidation with peroxytrifluoroacetic acid.In the second approach, α ',β-dihydroxy ketones are generated via cycloaddition of olefins with the nitrile oxide generated from 2--2-methyl-1-nitropropane followed by reductive ring opening.Standard periodic acid cleavage gives β-hydroxy acids.Finally, 3-methoxy-substituted Δ2-isoxazolines, readily available via benzenesulfonylcarbonitrile oxide-olefin cycloaddition and methoxide displacement, are directly reduced to β-hydroxy esters.
- Curran, Dennis P.,Scanga, Susan A.,Fenk, Christopher J.
-
p. 3474 - 3478
(2007/10/02)
-
- HYPERVALENT IODINE IN ORGANIC SYNTHESIS. A NEW ROUTE TO α-FUNCTIONALIZED CARBOXYLATE ESTERS.
-
Aryl and alkylcarboxylate esters are converted into the corresponding α-hydroxy acids or α-alkoxyesters upon treatment with C6H5I(OAc)2 and base in the appropriate solvent.
- Moriarty, Robert M.,Hu, Henry
-
p. 2747 - 2750
(2007/10/02)
-
- 144. Ueber die Stereoselektivitaet der α-Alkylierung von (1R,2S)(+)-cis-2-Hydroxy-cyclohexancarbonsaeureaethylester
-
In continuation of our work on the stereoselectivity of the α-alkylation of β-hydroxyesters , we studied this reaction with the title compound (+)-2.The latter was prepared through reduction of 1 with baker's yeast.Alkylation of the dianion of (+)-
- Frater, Gyoergy
-
p. 1383 - 1390
(2007/10/02)
-
