873-32-5Relevant articles and documents
One-step selective synthesis of 2-chlorobenzonitrile from 2-chlorotoluene: Via ammoxidation
Hari Babu,Venkateswara Rao,Suh,Sai Prasad,Lingaiah
, p. 1892 - 1901 (2018)
A series of V2O5/Al2O3 catalysts were prepared by a wet impregnation method and employed for a one-step synthesis of 2-chlorobenzonitrile from 2-chlorotoluene via ammoxidation in a fixed bed reactor at atmospheric pressure. The catalysts were characterized by BET-SA, XRD, FT-IR, TPR, UV-Vis DRS and NH3-TPD to identify the molecular structural changes of the catalysts. The characterization results revealed that the addition of V2O5 to Al2O3 amplified the crystallinity of alumina and also resulted in the formation of an interactive species i.e. AlVO4. Most of the V2O5 existed in the form of isolated surface and polymeric tetrahedral vanadia species in a highly dispersed state and/or having a strong interaction with the support. The formation of different kinds of vanadia species was entirely dependent on the content of vanadia present in the catalyst. A 10 wt% V2O5/Al2O3 catalyst was found to be the best and the high selectivity for 2-CBN was presumably due to the formation of the isolated surface and polymeric tetrahedral vanadia species along with aluminum vanadate species.
A DFT-assisted mechanism for evolution of the ammoxidation of 2-chlorotoluene (2-CLT) to 2-chlorobenzonitrile (2-CLBN) over alumina-supported V2O5 catalyst prepared by a solution combustion method
Dwivedi, Ritambhara,Sharma, Prabhakar,Sisodiya, Akrati,Batra, Manohar Singh,Prasad, Rajendra
, p. 245 - 257 (2017)
Ammoxidation of 2-chlorotoluene (2-CLT) has been carried out over vanadates and supported vanadates in the temperature range 350–450 °C. The catalysts were characterized by XRD, XPS, FT-IR, and Raman and surface area measurement. A maximum yield of 76% of 2-CLBN was obtained at a temperature of 425 °C and a 2-CLT:NH3:air mole ratio of 1:8:22. DFT computations suggest that the reaction follows a Mars–van Krevelen (MVK) type of redox mechanism. The catalyst is first reduced by ammonia, producing an imine species. The 2-CLT molecule is also adsorbed through a vanadyl oxygen to produce a CH2[dbnd]C6H5 species. This moiety is adsorbed over the catalyst through an imine formed on the surface to produce 2-chlorobenzonitrile. XPS spectra of fresh and spent catalysts confirm reduction of the catalyst during ammoxidation.
Cyanide-Free Cyanation of Aryl Iodides with Nitromethane by Using an Amphiphilic Polymer-Supported Palladium Catalyst
Niimi, Ryoko,Suzuka, Toshimasa,Uozumi, Yasuhiro
supporting information, p. 40 - 44 (2021/11/30)
A cyanide-free aromatic cyanation was developed that uses nitromethane as a cyanide source in water with an amphiphilic polystyrene poly(ethylene glycol) resin-supported palladium catalyst and an alkyl halide (1-iodobutane). The cyanation proceeds through the palladium-catalyzed cross-coupling of an aryl halide with nitromethane, followed by transformation of the resultant (nitromethyl)arene intermediate into a nitrile by 1-iodobutane.
Pd@CeO2-catalyzed cyanation of aryl iodides with K4Fe(CN)6·3H2O under visible light irradiation
Wang, Shengyu,Wang, Jianqiang,Pan, Junyi,Liu, Cheng,Gong, Xubin,Guo, Cheng
, (2021/01/12)
Cyanation of aryl iodides is still challenging work for chemical researchers because of harsh reaction conditions and toxic cyanide sources. Herein, we have developed a new protocol based on the combination of the catalyst Pd@CeO2, nontoxic cyanide source K4[Fe (CN)6]·3H2O, and driving force visible light irradiation. The reaction is operated at relatively moderate temperature (55°C) and exhibits good catalytic efficiency of product aryl nitriles (yields of 89.4%). Moreover, the catalyst Pd@CeO2 possesses good reusability with a slight loss of photocatalytic activity after five consecutive runs. The reaction system based on the above combination shows a wide range of functional group tolerance under the same conditions. Reaction conditions such as temperature, time, the component of catalyst, and solutions are optimized by studying cyanation of 1-iodo-4-nitrobenzene as model reaction. According to these results, the possible mechanism of Pd@CeO2-catalyzed cyanation of aryl iodides under visible light irradiation is proposed based on the influence of visible light on the catalyst and reactant compounds. In all, we provided an environmental and economic method for preparation of aryl nitriles from cyanation of aryl iodides based on the goal of green chemistry for sustainable development.
Biomass chitosan-derived nitrogen-doped carbon modified with iron oxide for the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles
Wang, Wei David,Wang, Fushan,Chang, Youcai,Dong, Zhengping
, (2020/11/24)
Nitrogen-doped carbon catalysts have attracted increasing research attention due to several advantages for catalytic application. Herein, cost-effective, renewable biomass chitosan was used to prepare a N-doped carbon modified with iron oxide catalyst (Fe2O3@NC) for nitrile synthesis. The iron oxide nanoparticles were uniformly wrapped in the N-doped carbon matrix to prevent their aggregation and leaching. Fe2O3@NC-800, which was subjected to carbonization at 800 °C, exhibited excellent activity, selectivity, and stability in the catalytic ammoxidation of aromatic aldehydes to aromatic nitriles. This study may provide a new method for the fabrication of an efficient and cost-effective catalyst system for synthesizing nitriles.
Synthetic method of o-chlorobenzonitrile
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Paragraph 0045-0052, (2021/03/18)
The invention discloses a synthesis method of o-chlorobenzonitrile, which comprises the following steps: by using one or more than two of o-chlorobenzyl alcohol, o-chlorobenzaldehyde and o-chlorobenzoic acid as raw materials, carrying out ammoxidation reaction in an ammonia gas and oxygen atmosphere under the actions of a copper-manganese composite catalyst and a cooxidant to synthesize the o-chlorobenzonitrile. By adopting the copper-manganese composite catalyst, one or more than two of the raw materials of o-chlorobenzyl alcohol, o-chlorobenzaldehyde and o-chlorobenzoic acid are subjected toammoxidation reaction to generate o-chlorobenzonitrile in the atmosphere of ammonia gas and oxygen under the synergistic action of the oxidant, so that the generation of byproducts is reduced, the difficulty of subsequent separation and purification is reduced, and the yield of o-chlorobenzonitrile is improved. The yield and purity of o-chlorobenzonitrile are improved, and the problems of low yield and high cost of o-chlorobenzonitrile caused by difficult separation and purification of products in the prior art are avoided.
Unprecedented Catalysis of Cs+Single Sites Confined in y Zeolite Pores for Selective Csp3-H Bond Ammoxidation: Transformation of Inactive Cs+Ions with a Noble Gas Electronic Structure to Active Cs+Single Sites
Acharyya, Shankha S.,Ghosh, Shilpi,Iwasawa, Yasuhiro,Kaneko, Takuma,Sasaki, Takehiko,Yoshida, Yusuke
, p. 6698 - 6708 (2021/06/25)
We report the transformation of Cs+ ions with an inactive noble gas electronic structure to active Cs+ single sites chemically confined in Y zeolite pores (Cs+/Y), which provides an unprecedented catalysis for oxidative cyanation (ammoxidation) of Csp3-H bonds with O2 and NH3, although in general, alkali and alkaline earth metal ions without a moderate redox property cannot activate Csp3-H bonds. The Cs+/Y catalyst was proved to be highly efficient in the synthesis of aromatic nitriles with yields >90% in the selective ammoxidation of toluene and its derivatives as test reactions. The mechanisms for the genesis of active Cs+ single sites and the ammoxidation pathway of Csp3-H bonds were rationalized by density functional theory (DFT) simulations. The chemical confinement of large-sized Cs+ ions with the pore architecture of a Y zeolite supercage rendered the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap reduction, HOMO component change, and preferable coordination arrangement for the selective reaction promotion, which provides a trimolecular assembly platform to enable the coordination-promoted concerted ammoxidation pathway working closely on each Cs+ single site. The new reaction pathway without involvement of O2-dissociated O atom and lattice oxygen differs from the traditional redox catalysis mechanisms for the selective ammoxidation.
One pot synthesis of aryl nitriles from aromatic aldehydes in a water environment
Chen, Qingqing,Han, Hongwei,Lin, Hongyan,Ma, Xiaopeng,Qi, Jinliang,Wang, Xiaoming,Yang, Yonghua,Zhou, Ziling
, p. 24232 - 24237 (2021/07/29)
In this study, we found a green method to obtain aryl nitriles from aromatic aldehyde in water. This simple process was modified from a conventional method. Compared with those approaches, we used water as the solvent instead of harmful chemical reagents. In this one-pot conversion, we got twenty-five aryl nitriles conveniently with pollution to the environment being minimized. Furthermore, we confirmed the reaction mechanism by capturing the intermediates, aldoximes.
Dehydration of aldoximes to nitriles using trichloroacetonitrile without catalyst
Ma, Xiaoyun,Liu, Dan,Chen, Zhengjian
, p. 3261 - 3266 (2021/06/30)
Trichloroacetonitrile has been found to be an efficient dehydrating agent for a range of aldoximes including aromatic and heterocyclic aldoxime yielding the corresponding nitriles in moderate to good yields. The dehydration reactions can take place in non-acetonitrile media without the aid of a metal catalyst. In addition, it has been confirmed that trichloroacetonitrile was converted into trichloroacetamide in the reaction.
Facile dehydration of primary amides to nitriles catalyzed by lead salts: The anionic ligand matters
Ruan, Shixiang,Ruan, Jiancheng,Chen, Xinzhi,Zhou, Shaodong
, (2020/12/09)
The synthesis of nitrile under mild conditions was achieved via dehydration of primary amide using lead salts as catalyst. The reaction processes were intensified by not only adding surfactant but also continuously removing the only by-product, water from the system. Both aliphatic and aromatic nitriles can be prepared in this manner with moderate to excellent yields. The reaction mechanisms were obtained with high-level quantum chemical calculations, and the crucial role the anionic ligand plays in the transformations were revealed.
