cas 50-84-0, 2,4-Dichlorobenzoic acid | Articles data

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Purification of 2,4 dichlorobenzoic acid
A practical and efficient method to purify 2,4-dichlorobenzoic acid is described. The formation of an α-methylbenzylamine salt reduces the levels of positional isomer impurities to 0.05%. Although this purification method is not universal for all substituted benzoic acids, it was shown to be applicable to several other benzoic acids.
Ley, Christopher P.,Yates, Matthew H.
p. 120 - 124
(2008)
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Continuous production method of benzoic acid derivative
The invention relates to the technical field of preparation of benzoic acid derivatives. The invention particularly relates to a continuous production method of a benzoic acid derivative. The continuous reaction device is characterized by comprising a small-diameter sleeve, wherein the small-diameter sleeve is sleeved with a large-diameter sleeve, and a small pipeline is arranged between the small-diameter sleeve and the large-diameter sleeve, and a plurality of small holes are arranged on the small pipeline. The small-diameter casing is rotated, the large-diameter casing is fixed, and the reaction liquid composed of the nitric acid and the toluene derivative is between a small-diameter casing pipe and a large-diameter casing pipe.
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Paragraph 0032-0033; 0035

(2021/11/14)

Sequential Connection of Mutually Exclusive Catalytic Reactions by a Method Controlling the Presence of an MOF Catalyst: One-Pot Oxidation of Alcohols to Carboxylic Acids
A functionalized metal-organic framework (MOF) catalyst applied to the sequential one-pot oxidation of alcohols to carboxylic acids controls the presence of a heterogeneous catalyst. The conversion of alcohols to aldehydes was acquired through aerobic oxidation using a well-known amino-oxy radical-functionalized MOF. In the same flask, a simple filtration of the radical MOF with mild heating of the solution completely altered the reaction media, providing radical scavenger-free conditions suitable for the autoxidation of the aldehydes formed in the first step to carboxylic acids. The mutually exclusive radical-catalyzed aerobic oxidation (the first step with MOF) and radical-inhibited autoxidation (the second step without MOF) are sequentially achieved in a one-pot manner. Overall, we demonstrate a powerful and efficient method for the sequential oxidation of alcohols to carboxylic acids by employing a readily functionalizable heterogeneous MOF. In addition, our MOF in-and-out method can be utilized in an environmentally friendly way for the oxidation of alcohols to carboxylic acids of industrial and economic value with broad functional group tolerance, including 2,5-furandicarboxylic acid and 1,4-benzenedicarboxylic acid, with good yield and reusability. Furthermore, MOF-TEMPO, as an antioxidative stabilizer, prevents the undesired oxidation of aldehydes, and the perfect "recoverability"of such a reactive MOF requires a re-evaluation of the advantages of MOFs from heterogeneity in catalytic and related applications.
Kim, Seongwoo,Lee, Ha-Eun,Suh, Jong-Min,Lim, Mi Hee,Kim, Min
supporting information
p. 17573 - 17582
(2020/12/22)

Selective Solvent-Free and Additive-Free Oxidation of Primary Benzylic C–H Bonds with O2 Catalyzed by the Combination of Metalloporphyrin with N-Hydroxyphthalimide
Abstract: A protocol for solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts to overcome the deficiencies encountered in current oxidation systems. The effects of reaction temperature, porphyrin structure, central metal, catalyst loading and O2 pressure were investigated systematically. For the optimized combination of T(2-OCH3)PPCo and NHPI, all the primary benzylic C–H bonds could be functionalized efficiently and selectively at 120 °C and 1.0?MPa O2 with aromatic acids as the primary products. The selectivity towards aromatic acids could reach up to 70–95% in the conversion of more than 30% for most of the substrates possessing primary benzylic C–H bonds in the metalloporphyrin loading of 0.012% (mol/mol). And the superior performance of T(2-OCH3)PPCo among the metalloporphyrins investigated was mainly attributed to its high efficiency in charge transfer and fewer positive charges around central metal Co (II) which favored the adduction of O2 to cobalt (II) forming the high-valence metal-oxo complex followed by the production of phthalimide N-oxyl radical (PINO) and the initiation of the catalytic oxidation cycle. This work would provide not only an efficient protocol in utilization of hydrocarbons containing primary benzylic C–H bonds, but also a significant reference in the construction of more efficient C–H bonds oxidation systems. Graphic Abstract: The solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts, and the highest selectivity towards aromatic acid reached up to 95.1% with the conversion of 88.5% in the optimized combination of T(2-OCH3)PPCo and NHPI.[Figure not available: see fulltext.].
Shen, Hai-Min,Qi, Bei,Hu, Meng-Yun,Liu, Lei,Ye, Hong-Liang,She, Yuan-Bin
p. 3096 - 3111
(2020/04/29)

Method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin
The invention relates to a method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin. The method comprises the following steps: dispersing metalloporphyrin and N-hydroxyphthalimide (NHPI) into methylbenzene and derivatives thereof, sealing the reaction system, heating to 70-130 DEG C while stirring, introducing oxygen to 0.2-2.0 MPa, keeping the set temperature and oxygen pressure, carrying out reactions for 8 hours under stirring, and carrying out after-treatment on the reaction solution to obtain the product aromatic acid. The method has the advantages of no solvent, no additive, mild conditions, higher selectivity to aromatic acids and good tolerance to substrates. The method not only can effectively oxidize hydrocarbon containing primary benzyl C-H bonds, but also can provide important reference for constructing a more effective C-H bond oxidation system, and is a novel efficient and feasible selective catalytic oxidation method for methylbenzene and derivatives thereof.
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Paragraph 0079-0080

(2020/09/30)

Copper (II) immobilized on magnetically separable L-arginine-β-cyclodextrin ligand system as a robust and green catalyst for direct oxidation of primary alcohols and benzyl halides to acids in neat conditions
Copper (II) immobilized on L-arginine-β-cyclodextrin-functionalized magnetite nanoparticles (nano-Fe3O4@L-arginine-CD-Cu(II)) were successfully synthesized and fully characterized using FT-IR, XRD, SEM, EDX, ICP, TGA and VSM techniques. The catalytic activity of these magnetically retrievable nanoparticles was evaluated in the direct oxidation of primary alcohols and benzyl halides to acids in neat conditions that was observed to proceed well and products were obtained in good yields. In addition to showing good catalytic activity, the magnetic catalyst is easy to synthesize and can be recycled at least five times with little loss in activity.
Nejad, Masoumeh Jadidi,Salamatmanesh, Arefe,Heydari, Akbar
(2020/02/11)

Palladium supported on a novel ordered mesoporous polypyrrole/carbon nanocomposite as a powerful heterogeneous catalyst for the aerobic oxidation of alcohols to carboxylic acids and ketones on water
Preparation of an ordered mesoporous polypyrrole/carbon (PPy/OMC) composite has been described through a two-step nanocasting process using KIT-6 as a template. Characterization of the PPy/OMC nanocomposite by various analysis methods such as TEM, XRD, TGA, SEM and N2 sorption confirmed the preparation of a material with ordered mesoporous structure, uniform pore size distribution, high surface area and high stability. This nanocomposite was then used for the immobilization of palladium nanoparticles. The nanoparticles were almost uniformly distributed on the support with a narrow particle size of 20-25 nm, confirmed by various analysis methods. Performance of the Pd?PPy/OMC catalyst was evaluated in the aerobic oxidation of various primary and secondary alcohols on water as a green solvent, giving the corresponding carboxylic acids and ketones in high yields and excellent selectivity. The catalyst could also be reused for at least 10 reaction runs without losing its catalytic activity and selectivity. High catalytic efficiency of the catalyst can be attributed to a strong synergism between the PPy/OMC and that of supported Pd nanoparticles.
Ganji, Nasim,Karimi, Babak,Najafvand-Derikvandi, Sepideh,Vali, Hojatollah
p. 13616 - 13631
(2020/04/24)

Acceptorless dehydrogenative oxidation of primary alcohols to carboxylic acids and reduction of nitroarenes via hydrogen borrowing catalyzed by a novel nanomagnetic silver catalyst
A novel silver nano magnetic catalyst was devised for dehydrogenative oxidation of aromatic and aliphatic alcohols to the corresponding acid with water as the sole oxygen source and hydrogen gas as the only by-product. The designed catalytic system advantages from easy recovery of magnetic materials i.e. magnetic decantation, being economically viable and environmentally friendly. Furthermore, the catalytic reaction is able to reduce aryl nitro compounds in the absence of any reducing agent.
Yazdani, Elahe,Heydari, Akbar
supporting information

(2020/08/14)

A tunable synthesis of either benzaldehyde or benzoic acid through blue-violet LED irradiation using TBATB
In this paper, a highly efficient, metal-free, and homogeneous method for the selective aerobic photooxidation of alcohols and photooxidative-desilylation of tert-butyldimethylsilyl ethers (TBDMS) in the presence of tetrabutylammonium tribromide (TBATB) under irradiation of visible light was reported. The light source: blue (460 nm) and violet (400 nm) LED, can control selective oxidation to aldehyde or carboxylic acid.
Mardani, Atefeh,Heshami, Marouf,Shariati, Yadollah,Kazemi, Foad,Abdollahi Kakroudi, Mazaher,Kaboudin, Babak
(2019/11/29)

Selective oxidation method for toluene compounds
The invention discloses a selective oxidation method for toluene compounds. The method comprises the following steps: 1, putting a toluene compound represented by a formula (I) shown in the specification, a metalloporphyrin catalyst, an oxidant and a dispersing agent into a ball milling tank, sealing the ball milling tank, carrying out ball milling for 3-24 hours at room temperature and the rotating speed of 100-800 rpm, stopping ball milling once every 1-3 hours in the ball milling process, discharging gas in the ball milling tank, and after the reaction is finished, carrying out post-treatment on the reaction mixture to obtain a product benzoic acid compound represented by a formula (II) shown in the specification. Oxidation conversion of methylbenzene and derivatives thereof is achievedthrough solid-phase ball milling, the reaction mode is novel, the operation is convenient, and the energy consumption is low; an organic solvent and other auxiliaries are not needed, so that use of toxic and harmful organic reagents is effectively avoided, and the method is green and environmentally friendly; the peroxide content is low, and the safety coefficient is high; and benzoic acid and derivatives thereof have high selectivity and meet the social requirements of a green chemical process, an environmental compatibility chemical process and a biological compatibility chemical process inthe prior art.
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Paragraph 0128; 0129

(2019/12/25)

Magnetic crosslinked copoly(ionic liquid) nanohydrogel supported palladium nanoparticles as efficient catalysts for the selective aerobic oxidation of alcohols
Nowadays it is still a great sustainable processes challenge to produce efficient, selective and easy magnetic recovery and recycling catalysts for oxidation of alcohols using air as the oxidant. In this work, a new magnetic nanohydrogel comprising [DABCO-allyl][Br] ionic liquid, allyl alcohol and N,N’-methylenebis(acrylamide) is used for stabilization of small and highly uniform palladium nanoparticles of 3–4 nm size MXCPILNHG@Pd. This material has been characterized by Fourier-transform infrared spectroscopy (FTIR), atomic adsorption spectroscopy (AAS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM-Map, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectra (XPS), vibrating-sample magnetometer (VSM) and dynamic light scattering (DLS). According to optimization of cross-linking degree and ratio of DABCO-IL, MXCPILNHG-2@Pd is found as a highly selective catalyst in oxidations of primary alcohols to the corresponding aldehydes in toluene and to acids in water. Furthermore, secondary alcohols were reacted efficiently to the corresponding ketones in both toluene and water. Catalyst is magnetically recovered and recycled for several times in both toluene and water and the reused catalysts are characterized by TEM and XPS.
Gholinejad, Mohammad,Afrasi, Mahmoud,Nikfarjam, Nasser,Nájera, Carmen
p. 185 - 195
(2018/07/14)

Unusual synthesis of azines and their oxidative degradation to carboxylic acid using iodobenzene diacetate
Reaction of 3-hydrazonobutan-2-one oxime with aromatic aldehydes resulted in the formation of 1,2-bis(arylidene)hydrazine commonly referred as azine as an unexpected product, instead of expected product 3-(aryl)methylenehydrazonobutan-2-one oxime, which were subsequently oxidized to corresponding aromatic acids with an ecofriendly oxidizing agent iodobenzene diacetate. Azines and carboxylic acids were characterized by IR and NMR (1H, 13C, HMBC, and HMQC) studies.
Sumran, Garima,Aggarwal, Ranjana,Hooda, Mona,Sanz, Dionisia,Claramunt, Rosa M.
supporting information
p. 439 - 446
(2018/02/06)

Synthesis method of antimalarial drug quinacrine hydrochloride intermediate 2,4-dichlorobenzoic acid
The invention discloses a synthesis method of an antimalarial drug quinacrine hydrochloride intermediate 2,4-dichlorobenzoic acid. The synthesis method mainly comprises: adding 4-5 mol N,N-dimethylacetamide solution and 3-4 mol boron trifluoride-acetic acid complex powder to a reaction container, controlling the stirring speed at 90-110 rpm, maintaining for 30-40 min, adding 2 mol 2,4-dichloro-6-amino-isobutylbenzene solution, heating the solution to a temperature of 40-50 DEG C, maintaining for 100-130 min, continuously heating to a temperature of 60-70 DEG C, maintaining for 30-40 min, precipitating, filtering, washing the precipitate by using a 1-chloro-2-methyl propane solution, combining the filtrate and washing solution, adding an oxalic acid solution, adjusting the pH value to 4-5,cooling the solution to a temperature of 10-15 DEG C, crystallizing, filtering, and dewatering with a dewatering agent to obtain the finished product 2,4-dichlorobenzoic acid.
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Paragraph 0010; 0012; 0013; 0014

(2018/11/03)

First electrospun immobilized molybdenum complex on bio iron oxide nanofiber for green oxidation of alcohols
Bio iron oxide was synthesized from natural Sesbania sesban plant and modified by a molybdenum complex (Fe2O3/MoSB). Fe2O3/MoSB was deposited on polyvinyl alcohol (PVA) using a conventional single nozzle electrospinning technique (PVA/Fe2O3/MoSB). TEM, SEM, AFM, FT-IR, TGA, EDAX, and elemental analysis were used to determine fiber compositional information. The catalytic efficiency of electrospun PVA/Fe2O3/MoSB nanofiber in the oxidation of alcohols was exploited. The green reactions were conducted at solvent free conditions as a green media in the presence of H2O2 to have the desired aldehydes and tert-butyl hydrogen peroxide to obtain acid products in high yields and excellent selectivity. The survival of this nanocomposite was investigated and it could be reused and recycled in consecutive runs.
Noghi, Sedighe Abbaspour,Naeimi, Atena,Hamidian, Hooshang
p. 229 - 237
(2018/07/13)

Technological method for preparing halogenated-3,4-dihydro-1H-2-naphthalenone
The invention relates to a technological preparation method of halogenated-3,4-dihydro-1H-2-naphthalenone as shown in a formula (I). (As shown in the description). According to the method disclosed by the invention, through a cheap raw material namely 2,4-dihalogeno-benzene carbonitrile, and an intermediate namely 2,4-dihalogeno-benzene acetic acid is synthesized, and through a reusable trifluoroacetic anhydride/acid system catalyst, a target product namely the halogenated-3,4-dihydro-1H-2-naphthalenone is synthesized. According to the method disclosed by the invention, a large quantity of catalysts such as aluminumtrichloride, and costly catalysts such as Rh, are not needed, and the reaction route can be shortened, so that a large quantity of reagents and time can be saved, and the industrial economic benefits can be greatly increased.
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Paragraph 0045; 0046

(2017/07/20)

Preparation and characterization of nanosized copper (II) oxide embedded in hyper-cross-linked polystyrene: Highly efficient catalyst for aqueous-phase oxidation of aldehydes to carboxylic acids
Preparation and catalytic properties of nanosized copper (II) oxide embedded in hypercrosslinked polystyrene (HPS) were investigated in this article. The CuO@HPS nanocomposite was characterized by inductively coupled plasma optical emission spectrometry (ICP-OES), Fourier transform infrared spectroscopy (FT-IR), N2-sorption analysis, X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy analysis (EDS), and transmission electron microscopy (TEM). The TEM analysis showed that the mean diameter of the resulted particles is ~ 4 nm. The nanocomposite was found to be efficient and durable catalyst in the oxidation of aldehydes to the corresponding carboxylic acids in water. The catalyst can be recycled and reused in 4 reaction runs.
Saadati, Fariba,Khani, Neda,Rahmani, Mohammad,Piri, Farideh
p. 26 - 30
(2016/04/04)

2-Oxo-Driven Coupling Reactions of 2-Oxo Aldehydes/2-Oxo Iminium Ions and Hydroperoxides at Room Temperature
An efficient 2-oxo-group-promoted direct coupling reaction between 2-oxo aldehydes and hydroperoxides has been developed. The method has been used successfully for the generation of different 2-oxo esters and acids. This reaction harnesses the hydrogen-bonding-induced self-decomposition tendency of hydroperoxides; the intermediates produced by this process then attack the aldehyde or iminium ion to generate cross-coupled products either by direct coupling or by an amine-catalysed pathway. No external oxidants or metal catalysts are required for our method, and the reaction takes place at room temperature.
Khan, Shahnawaz,Ahmed, Qazi Naveed
p. 5377 - 5385
(2016/11/22)

Iodine-catalyzed oxidative C-C bond cleavage for benzoic acids and benzamides from alkyl aryl ketones
Iodine-catalyzed oxidative C-C bond cleavage has been performed for the facile synthesis of both benzoic acids and benzamides from readily available alkyl aryl ketones. Additionally benzylidene acetones and phenylacetylenes were also converted to the corresponding aromatic acids under the same conditions. This approach features the use of inexpensive iodine as a catalyst, broad substrate scope and open air conditions.
Sathyanarayana, Pochampalli,Upare, Atul,Ravi, Owk,Muktapuram, Prathap Reddy,Bathula, Surendar Reddy
p. 22749 - 22753
(2016/03/15)

Promising hydrogen peroxide stabilizers for large-scale application: unprecedented effect of aryl alkyl ketones
Aryl alkyl ketones with substituents in the aromatic ring taken in an amount from 0.005 to 0.5% efficiently stabilize hydrogen peroxide in an aqueous solution during storage at 22–25°C for 16–24 months.
Terent'ev, Alexander O.,Pastukhova, Zhanna Yu.,Yaremenko, Ivan A.,Bruk, Lev G.,Nikishin, Gennady I.
p. 329 - 331
(2016/08/09)

Flow carbonylation of sterically hindered ortho-substituted iodoarenes
The flow synthesis of ortho-substituted carboxylic acids, using carbon monoxide gas, has been studied for a number of substrates. The optimised conditions make use of a simple catalyst system compromising of triphenylphosphine as the ligand and palladium acetate as the pre-catalyst. Carbon monoxide was introduced via a reverse "tube-in-tube" flow reactor at elevated pressures to give yields of carboxylated products that are much higher than those obtained under normal batch conditions.
Mallia, Carl J.,Walter, Gary C.,Baxendale, Ian R.
supporting information
p. 1503 - 1511
(2016/08/02)

Iron-Catalysed Selective Aerobic Oxidation of Alcohols to Carbonyl and Carboxylic Compounds
A method for aerobic alcohol oxidation catalysed by Fe(NO3)3/2,2’-bipyridine/TEMPO has allowed highly selective conversion of primary alcohols into either aldehydes or carboxylic acids in one-step. The oxidation of primary alcohols proceeded selectively to aldehydes, as TEMPO was present in the reaction. Nevertheless, the aldehydes were further oxidized into carboxylic acids as the reaction time was extended. Detailed investigation of the reaction suggested, that the deoxygenation of TEMPO into TMP enabled the auto-oxidation of aldehydes to carboxylic acids, which was initially inhibited in the presence of TEMPO. The procedure was also efficient in oxidation of secondary alcohols when TEMPO was replaced by the less sterically hindered ABNO.
Lagerblom, Kalle,Wrigstedt, Pauli,Keskiv?li, Juha,Parviainen, Arno,Repo, Timo
p. 1160 - 1165
(2016/11/23)

DMSO/I2 mediated C-C bond cleavage of α-ketoaldehydes followed by C-O bond formation: A metal-free approach for one-pot esterification
A novel and efficient I2/DMSO mediated metal-free strategy is presented for the direct C-C bond cleavage of aryl-/heteroaryl- or aliphatic α-ketoaldehydes by C2-decarbonylation and C1-carbonyl oxidation to give the corresponding carboxylic acids followed by esterification in one pot, offering excellent yields in both the steps. Here, DMSO acts as the oxygen source/oxidant and this reaction works very well under both conventional heating and microwave irradiation. This is a very simple and convenient protocol.
Venkateswarlu, Vunnam,Aravinda Kumar,Gupta, Sorav,Singh, Deepika,Vishwakarma, Ram A.,Sawant, Sanghapal D.
p. 7973 - 7978
(2015/07/27)

A Metal-Free Approach to Carboxylic Acids by Oxidation of Alkyl, Aryl, or Heteroaryl Alkyl Ketones or Arylalkynes
The metal-free oxidation of dialkyl, alkyl aryl, or alkyl heteroaryl ketones or arylalkynes to the corresponding carboxylic acids is achieved using an oxidative mixture of Oxone and trifluoroacetic acid. This green method is a simple and mild protocol to obtain carboxylic derivatives in excellent yields.
Aravinda Kumar,Venkateswarlu, Vunnam,Vishwakarma, Ram A.,Sawant, Sanghapal D.
p. 3161 - 3168
(2015/10/19)

Copper catalyzed oxygen assisted C(CNOH)-C(alkyl) bond cleavage: A facile conversion of aryl/aralkyl/vinyl ketones to aromatic acids
A novel copper-catalyzed aerobic oxidative C(NOH)-C(alkyl) bond cleavage reaction of aryl/aralkyl/vinyl ketones for the synthesis of aromatic/acrylic acids is described. A series of ketones having aryl/aralkyl/vinyl at the one end and methyl to any higher alkyl at the other end can be selectively cleaved and converted into the corresponding acids via oxime intermediates.
Sathyanarayana, Pochampalli,Ravi, Owk,Muktapuram, Prathap Reddy,Bathula, Surendar Reddy
supporting information
p. 9681 - 9685
(2015/09/28)

Metal-free oxidative cleavage of the C-C bond in α-hydroxy-β-oxophosphonates
The potential of TBHP to promote oxidative hydroxylation of α-hydroxy-β-oxophosphonates (HOPs) through C(CO)-C bond cleavage is described. This cleavage, as depicted in the mechanism is expected through an isomer of HOP that reacts with TBHP to generate acids.
Battula, Satyanarayana,Kumar, Atul,Ahmed, Qazi Naveed
supporting information
p. 9953 - 9956
(2015/10/12)

Synthesis of benzoyl cyanide through aerobic photooxidation of benzyl cyanide using carbon tetrabromide as a catalyst
We developed a synthetic method toward benzoyl cyanide through aerobic photooxidation of benzyl cyanide in the presence of carbon tetrabromide under visible light irradiation with fluorescent lamps.
Sugiura,Tachikawa,Nagasawa,Tada,Itoh
p. 70883 - 70886
(2015/09/08)

Nanoparticle-supported and magnetically recoverable organic-inorganic hybrid copper(ii) nanocatalyst: A selective and sustainable oxidation protocol with a high turnover number
A magnetically recoverable copper-based nanocatalyst was prepared from inexpensive starting materials. With a particle size between 20 to 30 nm, it was shown to catalyze the oxidation of benzylic alcohols. The catalyst exhibited a high turnover number (TON) and excellent selectivity. The catalyst was characterized by several techniques, such as XRD, HR-TEM, SAED, EDS, FT-IR, VSM, and BET surface area. Factors affecting the reaction parameters, such as the substrate to oxidant molar ratio, weight of the catalyst, reaction time, etc., were investigated in detail. The reusability of the catalyst was examined by conducting repeat experiments with the same catalyst; it was observed that the catalyst displayed no significant changes in its activity even after seven cycles for the aerobic, as well as for the peroxide, oxidation of benzyl alcohol. Furthermore, the heterogeneous nature, easy recovery, and reusability, makes the present protocol highly beneficial for addressing environmental concerns and industrial requirements. This journal is
Rathore, Puran Singh,Patidar, Rajesh,Thakore, Sonal
p. 41111 - 41121
(2014/12/10)

Oxidation of aldehydes to carboxylic acids with hydrogen peroxide and PTSA catalyzed by β-cyclodextrin
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Jeong, Se Young,Kim, Nagyeong,Lee, Jong Chan
p. 3366 - 3368
(2015/04/22)

Calcium and magnesium chlorides-catalyzed oxidative esterification of aromatic aldehydes
An interesting procedure for the oxidative esterification of aromatic aldehydes has been developed. By using catalytic amount of CaCl2 or MgCl2, various methyl benzoates were isolated in good yields with hydrogen peroxide as the terminal oxidant.
Feng, Jian-Bo,Gong, Jin-Long,Li, Qin,Wu, Xiao-Feng
p. 1657 - 1659
(2014/03/21)

Au/mesoporous-TiO2 as catalyst for the oxidation of alcohols to carboxylic acids with molecular oxygen in water
Mesoporous TiO2 (meso-TiO2) with sharp pore size distribution was synthesized by hydrothermal method. The obtained meso-TiO 2 is in pure anatase phase and presents spheric aggregates with diameter of 1.0-1.5 μm, which consists of nanoparticles with size of 6-10 nm. Au supported on meso-TiO2 (Au/meso-TiO2) was prepared by urea deposition-precipitation method using HAuCl4 as gold source. The catalyst was characterized by X-ray diffraction, N2 adsorption, transmission electron microscopy and UV-vis diffuse reflectance spectroscopy. The catalytic performance of Au/meso-TiO2 was studied in the oxidation of 1-pentanol to n-valeric acid with molecular oxygen as oxidant in water under basic conditions. It was found that meso-TiO2 is a better support for gold catalyst in the oxidation of 1-pentanol than NaY zeolite, hydrotalcite, and nano-TiO2. Deposition-precipitation time, calcination temperature and Au loading affected the catalytic performance of Au/meso-TiO2. The catalyst can also effectively catalyze the oxidation of aliphatic (C3-C10) and aromatic alcohols to the corresponding carboxylic acids.
Zhou, Lipeng,Chen, Minzhu,Wang, Youqiang,Su, Yunlai,Yang, Xiaomei,Chen, Chen,Xu, Jie
p. 347 - 354
(2014/03/21)

SnO 2 nanoparticles: Preparation and evaluation of their catalytic activity in the oxidation of aldehyde derivatives to their carboxylic acid and sulfides to sulfoxide analogs
A variety of aromatic and aliphatic aldehydes were converted to the corresponding carboxylic acid derivatives with 30% H2O2 and tert-butyl hydroperoxide as the oxidant in the presence of a catalytic amount of SnO2 nanoparticles as a precursor. These nanoparticles were also used for the efficient catalytic oxidation of sulfides to sulfoxides using 30% H2O2. The present methodology offers several advantages such as applicability to a wide range of aldehydes/sulfides, convenient work-up, mild reaction conditions as well as good yields and reasonable time of the reactions. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
Dehbashi, Mohsen,Aliahmad, Mousa,Shafiee, Mohammad Reza Mohammad,Ghashang, Majid
p. 864 - 872
(2013/08/23)

Nickel(II) catalyzed oxidation of aldehyde derivatives to their carboxylic acid or ester analogs
Diverse aromatic, aliphatic and conjugated aldehydes were converted to the corresponding carboxylic acid or methyl ester derivatives with 30 % H 2O2 as the oxidant in the presence of a catalytic amount of nickel(II) complex as precursor. Ni(II) complex was prepared from the reaction of methyl 2-{3-[(E)-4-oxopent-2-en-2-ylamino]propylamino}cyclopent-1- enecarbodithioate as a tetra-dentate ligand with Ni(II) acetate in 60 % yield and was tested for its catalytic activity in the oxidation reaction. The prepared complex was characterized on the basis of 1H NMR, FT-IR, MASS, and CHN analysis. Aldehydes were oxidized to their corresponding carboxylic acid in acetonitrile as solvent and were converted to methyl esters in methanol as solvent. For all substrates, a considerable rate enhancement was observed. The present methodology offers several advantages such as applicability to a wide range of aldehydes, convenient work-up, mild reaction conditions, and good yields and reasonable time of the reactions. Graphical Abstract: [Figure not available: see fulltext.]
Esfandiari, Hadi,Jameh-Bozorghi, Saeed,Esmaielzadeh, Sheida,Shafiee, Mohammad Reza Mohammad,Ghashang, Majid
p. 3319 - 3325
(2013/09/23)

Sulfonic acid resin-catalyzed oxidation of aldehydes to carboxylic acids by hydrogen peroxide
Oxidation of benzaldehyde to benzoic acid can be performed efficiently with 30% H2O2 as the oxidant and sulfonic acid resin Amberlyst 15 as the catalyst. The reactivities of benzaldehyde derivatives are determined by both hindrance effect and electron effect of substituents, and benzaldehyde derivatives with electron-withdrawing group at the meta- or para-position are highly active and almost quantitatively converted into their corresponding acids. In addition, this method also works well for the oxidation of aliphatic aldehydes. The key characteristic of the procedure is that the catalyst is recyclable.
Yang, Xiaomei,Tang, Si,Lu, Tianliang,Chen, Chen,Zhou, Lipeng,Su, Yunlai,Xu, Jie
p. 979 - 985
(2013/02/25)

Synthesis of stilbene, 1,4-distyrylbenzene and 4,4′-distyrylbiphenyl via Horner-Wadsworth-Emmons reaction in phase-transfer catalysis system
Stilbenes, 1,4-distyrylbenzenes and 4,4′-distyrylbiphenyls were synthesized via Horner-Wadsworth-Emmons (HWE) reaction in liquid-liquid (LL) and solid-liquid (SL) phase transfer catalysis (PTC) systems. The effect of the side reaction, reactants and the third phase on the activity of HWE reaction were investigated. For aldehydes bearing electron-donating substitute, the yields were more than 90% and the products were all (E)-isomers in both PTC systems. The SL-PTC system was milder than LL-PTC system for HWE reaction due to the different mechanisms. The side reaction of aldehyde was similar to Cannizzaro reaction, whereas the molar ratio of benzoic acid to benzyl alcohol as the products was not 1:1. The limited third phase was discovered to exist in LL-PTC system. In SL-PTC system, the third phase could increase substantially the reaction rate. Moreover, the aqueous phase in LL-PTC system could be reused four times without sacrifice of the yield and reaction rate.
Zhao, Qiangqiang,Sun, Jie,Liu, Baojiang,He, Jinxin
p. 339 - 347
(2013/10/21)

A comparative study of different metal acetylacetonates covalently anchored onto amine functionalized silica: A study of the oxidation of aldehydes and alcohols to corresponding acids in water
A series of metal acetylacetonates covalently anchored onto amine functionalized silica were prepared by the complexation of metal acetylacetonates [Co(acac)2, Cu(acac)2, Pd(acac) 2, Ru(acac)3, Mn(acac)3, Co(acac)3] with organically modified 3-aminopropyl silica and their catalytic activities were tested for the oxidation of aromatic aldehydes, α,β-unsaturated aldehydes and benzyl alcohols to the corresponding carboxylic acids in aqueous medium. Different metal acetylacetonates have been chosen with a view to select the most active heterogeneous catalyst for oxidations. The characterization of the catalysts was done on the basis of FTIR, TGA and AAS analysis. SiO 2-Co(acac)2 catalyzes the oxidation of aromatic aldehydes under air atmosphere without using any additional oxidant; however, t-BuOOH was found to be a highly efficient oxidant for the oxidation of α,β- unsaturated aldehydes and heterocyclic aldehydes, as well as the direct oxidation of benzyl alcohols to the corresponding carboxylic acids. The most active catalyst was found to be highly stable and recyclable under the reaction conditions. The Royal Society of Chemistry.
Sodhi, Ravinderpal Kour,Paul, Satya,Clark
p. 1649 - 1656
(2013/02/22)

Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
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.
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information
p. 8986 - 8998,13
(2012/12/12)

Novel 2,2,6,6-tetramethylpiperidine 1-oxyl-iodobenzene hybrid catalyst for oxidation of primary alcohols to carboxylic acids
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.
Yakura, Takayuki,Ozono, Ayaka
experimental part
p. 855 - 859
(2011/06/26)

A green, reusable and highly efficient solid acid catalyst for the oxidation of aldehydes to the corresponding carboxylic acids using H 2O2 and KMnO4:H5PV 2Mo10O40 (10-molybdo-2-vanadophosphoric heteropolyacid)
H5PV2Mo10O40-catalyzed oxidation of aromatic aldehydes to the corresponding carboxylic acids using hydrogen peroxide and KMnO4 as oxidants under mild conditions is reported. This system provides an efficient, convenient and practical method for the oxidation of aromatic aldehydes. In this work, differences between Keggin and Well-Dawson type polyoxometalates are addressed in term of relative stability, hardness and acidity.
Shojaei, Abdollah Fallah,Rezvani, Mohamad Ali,Heravi, Majid
experimental part
p. 1513 - 1522
(2012/03/08)

Green oxidation of methylarenes to benzoic acids with bromide/bromate in water
An efficient and convenient procedure has been developed for the oxidation of methylarenes to the corresponding benzoic acids using a bromide/bromate-based reagent system in water. Regeneration and reusability of the bromide/bromate reagent is demonstrated.
Patil, Rajendra D.,Bhadra, Sukalyan,Adimurthy, Subbarayappa,Ranu, Brindaban C.
experimental part
p. 2922 - 2929
(2010/11/05)

Selective oxidation of aromatic primary alcohols to aldehydes using molybdenum acetylide oxo-peroxo complex as catalyst
Selective oxidation of various aromatic alcohols to aldehydes has been carried out with very high conversion (90%) and selectivity (90%) for aldehydes using cyclopentadienyl molybdenum acetylide complex, CpMo(CO)3(C{triple bond, long}CPh) (1) as catalyst and hydrogen peroxide as environmentally benign oxidant. Water-soluble Mo acetylide oxo-peroxo species is formed in situ after reaction of 1 with aqueous hydrogen peroxide during the course of reaction as catalytically active species. Interestingly even though the catalyst is homogeneous it could be recycled very easily by separating the products in organic phase and catalyst in aqueous phase using separating funnel. Even after five recycles no appreciable loss in alcohol conversion and aldehyde selectivity was observed.
Biradar, Ankush V.,Dongare, Mohan K.,Umbarkar, Shubhangi B.
experimental part
p. 2885 - 2888
(2009/09/06)

INHIBITORS OF STEAROYL-COA DESATURASE
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.
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(2009/06/27)

WO3/70% TBHP/aqueous NaOH: An efficient catalytic combination for the selective oxidation of methylarenes and alkyl aryl ketones to benzoic acids
A new solvent-free, reusable catalytic combination consisting of WO 3/70% TBHP/aqueous NaOH has been described for the direct oxidation of methylarenes and acetophenones to the corresponding benzoic acids in high yields. Alkylarenes are oxidized to the corresponding aromatic ketones or benzylic alcohols depending upon whether NaOH is used or not. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
Shaikh, Tanveer Mahammad Ali,Sudalai, Arumugam
experimental part
p. 4877 - 4880
(2009/05/30)

Carboxylation and esterification of functionalized arylcopper reagents
Functionalized arylcopper reagents have been produced in good yields at 25 °C from activated copper and the corresponding functionalized aryl iodides without the need of traditional organolithium or Grignard precursors. These organocopper compounds will undergo carboxylation with CO2 to form the corresponding copper benzoates. In turn, these salts can be acidified to produce the functionalized aryl acids or treated with appropriate alkyl halides in the presence of a dipolar aprotic solvent to generate the corresponding aryl esters. This methodology permits the formation of functionalized organic acids and esters that could not be generated by the carboxylation of organomagnesium compounds.
Ebert, Greg W.,Juda, Wayne L.,Kosakowski, Robert H.,Ma, Bing,Dong, Liming,Cummings, Keith E.,Phelps, Mwita V. B.,Mostafa, Adel E.,Luo, Jianyuan
p. 4314 - 4317
(2007/10/03)

Buttressing Effects Rerouting the Deprotonation and Functionalization of 1,3-Dichloro- and 1,3-Dibromobenzene
A systematic comparison between 1,3-difluorobenzene, 1,3-dichlorobenzene, and 1,3-dibromobenzene did not reveal major differences in their behavior towards strong bases such as lithium diisopropylamide or lithium 2,2,6,6-tetramethyl-piperidide. Thus, all 2,6-dihalobenzoic acids 1 are directly accessible by consecutive treatment with a suitable base and dry ice. In contrast, (2,6-dichlorophenyl)- and (2,6-bromo-phenyl)triethylsilane (2a and 2b) were found to undergo deprotonation at the 5-position (affording acids 3 and, after deprotection, 4), whereas the 1,3-difluoro analog is known to react at the 4-position. The 2,4-dihalobenzoic acids 7 were selectively prepared from either the silanes 2 (by bromination at the 4-position, metalation and carboxylation of the neighboring position, followed by desilylation and debromination) or the 1,3-dihalo-2-iodobenzenes 8 (by base-promoted migration of iodine to the 4-position followed by iodine/magnesium permutation and subsequent carboxylation). Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Heiss, Christophe,Marzi, Elena,Schlosser, Manfred
p. 4625 - 4629
(2007/10/03)

Hydrogen peroxide oxidation of N,N-dimethylhydrazones promoted by selenium compounds, titanosilicalites or acetonitrile
Hydrogen peroxide oxidation of N,N-dimethylhydrazones 1 promoted by title reagents has been investigated. Depending on the substrate nitrile 2 and/or amide 3 accompanied with carboxylic acid 4 and parent carbonyl compounds 5 were obtained. Formation of nitriles 2 with H2O2-acetonitrile system is limited for a few more active substrates. The mechanism of the reaction, based on generated in situ peroxyiminoacetic acid, is presented. A broad spectrum of aliphatic, unsaturated and aromatic nitriles 2 was obtained by oxidation of corresponding N,N-dimethylhydrazones 1 with hydrogen peroxide in the presence of poly(bis-9,10-anthracenyl) diselenide (PADS) (7) as catalyst.
Giurg,Mlochowski,Ambrozak
p. 1713 - 1720
(2007/10/03)

Polystyrene-bound phenylseleninic acid: Catalytic oxidation of aldehydes to carboxylic acids with hydrogen peroxide
Polystyrene-bound phenylseleninic acid was prepared conveniently and aldehydes were catalytically oxidised to carboxylic acids with hydrogen peroxide using this polymer as catalyst.
Qian, Hao,Shao, Li-Xiong,Huang, Xian
p. 514 - 515
(2007/10/03)

One-pot oxidation of azomethine compounds into arenecarboxylic acids
Aromatic azomethine compounds, such as aldazines 1, aldoximes 7 and tosylhydrazones 8 oxidized with 30% hydrogen peroxide in the presence of poly(bis-1,2-phenylene) diselenide (6) as catalyst produce arenecarboxylic acids 2 mostly in high to excellent yields. The presented one-pot procedure has a synthetic value.
Giurg,Said,Syper,Mlochowski
p. 3151 - 3159
(2007/10/03)

Oxidation of dibenzyl ethers by dilute nitric acid
A simple process for the manufacture of benzaldehyde (BzH) by oxidation of dibenzyl ether (DBE) has been reported in this paper. Two-phase reaction between dibenzyl ether and aqueous dilute nitric acid in the presence of catalytic amount of sodium nitrite has been investigated. Effect of stirring speed, concentration of nitric acid in the aqueous phase, mole ratio of reactants, sodium nitrite concentration, and reaction temperature on the conversion of DBE and yield of BzH has been investigated. 80% yield of BzH with 95% conversion of DBE has been reported. Oxidation of bis(chlorobenzyl) ethers to corresponding aldehydes is difficult compared to oxidation of DBE under otherwise identical conditions. Initial concentration of sodium nitrite does not affect the overall progress of the reaction.
Joshi,Sawant,Joshi
p. 152 - 157
(2013/09/07)

Selenium(IV) oxide catalyzed oxidation of aldehydes to carboxylic acids with hydrogen peroxide
A convenient method for oxidative transformation of aromatic, heteroaromatic and aliphatic aldehydes into carboxylic acids is presented. It is based on the oxidation of aldehydes in THF using 30% hydrogen peroxide in the presence of 5 molar % of selenium(IV) oxide. The scope and limitation of the method are discussed.
Brzaszcz,Kloc,Maposah,Mlochowski
p. 4425 - 4434
(2007/10/03)

Microwave assisted oxidation of aromatic aldehydes
Aromatic aldehydes are converted to carboxylic acids in 6-8 minutes, and in the absence of any external promoting agent, under microwave irradiation conditions.
Sahadeva Reddy,Pratap Reddy,Reddy
p. 2949 - 2951
(2007/10/03)