100-64-1Relevant articles and documents
Mesoporous silica gel as an effective and eco-friendly catalyst for highly selective preparation of cyclohexanone oxime by vapor phase oxidation of cyclohexylamine with air
Liu, Shuilin,You, Kuiyi,Jian, Jian,Zhao, Fangfang,Zhong, Wenzhou,Yin, Dulin,Liu, Pingle,Ai, Qiuhong,Luo, He'an
, p. 239 - 249 (2016)
A simple and environmentally benign approach to highly selective preparation of cyclohexanone oxime by vapor phase catalytic oxidation of cyclohexylamine with air over mesoporous silica gel under atmospheric pressure has been successfully developed in this work. The results demonstrate that the nonmetallic mesoporous silica gel is an effective and eco-friendly catalyst for the vapor phase selective oxidation of cyclohexylamine to cyclohexanone oxime and the surface silicon hydroxyl groups as active sites are responsible for the excellent catalytic performance of silica gel. The present silica gel catalyst has advantages of low cost, long-time stable reactivity, easy regeneration, and reusability. This method employing inexpensive mesoporous silica gel as catalyst and air as green terminal oxidant under facile conditions is a promising process and has the potential to enable sustainable production of cyclohexanone oxime from the selective oxidation of cyclohexylamine with air in industrial applications.
An investigation into cyclohexanone ammoximation over Ti-MWW in a continuous slurry reactor
Zhao, Song,Xie, Wei,Yang, Junxia,Liu, Yueming,Zhang, Yingtian,Xu, Biliang,Jiang, Jin-Gang,He, Mingyuan,Wu, Peng
, p. 1 - 8 (2011)
In the present study, the liquid-phase ammoximation of cyclohexanone with ammonia and hydrogen peroxide was studied using a MWW-type titanosilicate (Ti-MWW) catalyst in a continuous slurry reactor to develop a clean process for producing cyclohexanone oxime. The reaction parameters, which governed the cyclohexanone conversion, oxime selectivity and catalyst deactivation, were investigated by simulating the operating conditions of an industrial process. Under optimized reaction conditions, Ti-MWW produced a cyclohexanone conversion and oxime selectivity over 96% and 99%, respectively. Moreover, Ti-MWW was extremely robust and showed a longer lifetime than the conventional titanium silicalite-1 catalyst. The causes of deactivation were elucidated to be the coke deposition and partial dissolution of the zeolite framework of Ti-MWW during ammoximation. The deactivated Ti-MWW catalyst was regenerated effectively by a combination of acid treatment and cyclic amine-assisted structural rearrangement.
Preparation of cyclic ketoximes using aqueous hydroxylamine in ionic liquids
Ren, Rex X,Ou, Wei
, p. 8445 - 8446 (2001)
Cyclohexanone oxime (the precursor for making ε-caprolactam) is readily prepared from cyclohexanone using aqueous hydroxylamine in ionic liquids.
A new route to lactam precursors from cycloalkanes: Direct production of nitrosocycloalkanes or cycloalkanone oximes by using tert-Butyl nitrite and N-hydroxyphthalimide
Hirabayashi, Tomotaka,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 1120 - 1123 (2004)
Clean and selective: Nitrosation and oximation of cycloalkanes was achieved by treating them with tBuONO under Ar in the presente presence of a catalytic amount of N-hydroxyphthalimide (see scheme). The novel, clean nitrosation procedure uses halogen-free, relatively mild reaction conditions and results in good product selectivity (almost no organic byproducts) and high recovery of the catalyst.
A novel hydroxylamine ionic liquid salt resulting from the stabilization of NH2OH by a SO3H-functionalized ionic liquid
Li, Zhihui,Yang, Qiusheng,Qi, Xudong,Xu, Yuanyuan,Zhang, Dongsheng,Wang, Yanji,Zhao, Xinqiang
, p. 1930 - 1932 (2015)
A SO3H-functionalized ionic liquid was used as an alternative to conventional inorganic acids in hydroxylamine stabilization, leading to the formation of a novel hydroxylamine ionic liquid salt that exhibits improved thermal stability and reactivity in the one-step, solvent-free synthesis of caprolactam in comparison with hydroxylamine hydrochloride and hydroxylamine sulfate.
Direct cyclohexanone oxime synthesis: Via oxidation-oximization of cyclohexane with ammonium acetate
Peng, Ling,Liu, Chan,Li, Na,Zhong, Wenzhou,Mao, Liqiu,Kirk, Steven Robert,Yin, Dulin
, p. 1436 - 1439 (2020)
An unexpected cascade reaction for oxidation-oximization of cyclohexane with ammonium acetate was developed for the first time to access cyclohexanone oxime with 50.7% selectivity (13.6% conversion). Tetrahedral Ti sites in Ni-containing hollow titanium silicalite can serve as bifunctional catalytic centers in the reaction. This methodology not only provides a direct approach to prepare cyclohexanone oxime, but also simplifies process chemistry. Various available nitrogen sources, such as ammonium salt and even ammonia can be used as starting materials.
A clean conversion of carbonyl compounds to oximes using silica gel supported hydroxylamine hydrochloride
Kiasat, Ali Reza,Kazemi, Foad,Nourbakhsh, Kazem
, p. 1193 - 1196 (2004)
The efficient condensation of carbonyl compounds with hydroxylamine hydrochloride under solvent free conditions is described.
Selective heterocyclic amidine inhibitors of human inducible nitric oxide synthase
Moormann, Alan E.,Metz, Sue,Toth, Mihaly V.,Moore, William M.,Jerome, Gina,Kornmeier, Christine,Manning, Pamela,Hansen Jr., Donald W.,Pitzele, Barnett S.,Webber
, p. 2651 - 2653 (2001)
The potency and selectivity of a series of 5-hetero-2-iminohexahydroazepines were examined as inhibitors of the three human NOS isoforms. The effect of ring substitution of the 5-carbon for a heteroatom is presented. Potencies (IC50's) for these inhibitors are in the low micromolar range for hi-NOS with some examples exhibiting a 500× selectivity versus hec-NOS.
Mercury-catalyzed rearrangement of ketoximes into amides and lactams in acetonitrile
Ramalingan, Chennan,Park, Yong-Tae
, p. 4536 - 4538 (2007)
(Chemical Equation Presented) An acetonitrile solution of mercury(II) chloride has been found to catalyze efficiently the conversion of a diverse range of ketoximes into their corresponding amides/lactams.
Pd/C Catalyzed selective hydrogenation of nitrobenzene to cyclohexanone oxime in the presence of NH2OH·HCl: Influence of the operative variables and insights on the reaction mechanism
Pietrobon, L.,Pontello, R.,Ronchin, L.,Sadraoui, C.,Tosetto, C.,Vavasori, A.
, (2020)
We studied the influence of temperature, solvent, pressure, catalysts type on the selectivity of nitrobenzene hydrogenation to cyclohexanone oxime (COX) in the presence of NH2OH. The best reaction conditions are: pressure 0.8 MPa, temperature 333 K, solvent ethers, and catalyst Pd/C5%. Other hydrogenation metal catalysts did not give comparable results. The amount of Pd/C influences the yield in COX, which rises above to 90 % at the highest load. The reaction profile shows that aniline is the reaction intermediate. Indeed, aniline as a substrate gives COX, though in lower yield than that achieved employing nitrobenzene. The NH2OH parallel hydrogenation to NH4Cl, influences positively the selectivity to COX. It has been observed that COX, cyclohexanone and N-cyclohexylideneaniline are in equilibrium in the reaction solution and all likely derive from nucleophilic substitutions to a common imine intermediate formed on the Pd surface, whose high activity does not need any further metal catalyst.
