Silica Gel Supported Trifluoromethanesulfonic Acid Catalyzed Beckmann Rearrangement of Cyclohexanone Oxime in Liquid Phase

The liquid phase Beckmann rearrangement of cyclohexanone oxime (CHO) using fuming sulfuric acid as a catalyst is a traditional method for preparing ε-caprolactam (CPL). This process has drawbacks, such as environmental pollution, corrosion of equipment, and low added value of by-product ammonium sulfate. This article designed and prepared a green silica gel-supported trifluoromethanesulfonic acid catalyst for the liquid-phase Beckmann rearrangement of CHO to prepare (CPL). The influencing factors of catalyst preparation and the optimal reaction conditions for Beckmann rearrangement were investigated. It was found that the optimal conditions for catalyst preparation were as follows: raw material silica gel:trifluoromethanesulfonic acid = 1:0.2 (mass ratio), room temperature, stirring time of 2.5 hours, and solvent of acetonitrile, silica gel mesh size is 100 - 200. The optimal reaction conditions for Beckmann rearrangement are CHO: catalyst = 1:2 (mass ratio), temperature of 130˚C, solvent of benzonitrile, volume of 30 mL/g CHO, and reaction time of 4 hours. Under the above conditions, the conversion of CHO is 90%, and the selectivity of CPL is 90%.

Decontamination of Chemical Warfare Agents by Novel Oximated Acrylate Copolymer

A novel acrylate copolymer,polymethylacrylate-β-(bromoacetyl ethyl)ester-co-N,N-dimethylacrylamide[P(MABE-co-DMAA)]was synthesized by the copolymerization of N,N-dimethylacrylamide and methylacrylate-β-(bromoacetyl ethyl)ester.Subsequently,the copolymer was oximated by 4-pyridinium aldoxime(4-PAM),and was abbreviated as PAM-P(MABE-co-DMAA).A maximum oxime conversion of 53.7%was obtained.The as-prepared oximated copolymer PAM-P(MABE-co-DMAA)effectively decontaminated chemical warfare agents(CWAs)including methylphosphonofluoridate(sarin or GB),S-2-(diisopropylamino)ethyl O-ethyl methylphosphonothioate(VX),and 2,2′-dichloroethyl sulfide(sulfur mustard,or HD).The detoxification rates were 90.6%for GB,85.7%for VX,and 90.5%for HD.Chromogenic analysis,high performance liquid chromatography-mass spectrometry(HPLC/MS)and gas chromatography-mass spectrometry(GC/MS)were used to identify the decontamination products,and the decontamination mechanism was concluded to be a combination of nucleophilic substitution and a second order Beckmann rearrangement.Furthermore,the active decontamination materials,such as decontamination cloths and covers could be made from the oximated copolymer by virtue of its processability,as well as its strong ability to degrade CWA.

Milbemycin Oxime半抗原设计及其抗体制备

通过milbemycin oxime A4、A3(MILO)肟羟基与琥珀酸酐反应,合成了半抗原MILO-5-琥珀酰半酯,采用碳化二亚胺法将其与载体蛋白BSA偶联制备人工抗原.以此人工抗原免疫新西兰大白兔获得多克隆抗体,抗体效价达1:12 800;用此抗体建立的间接竞争酶联免疫吸附(CI-ELISA)检测方法,线性范围在16.00～4 394.18 ng/mL,最低检测限(I10)为6.28 ng/mL.

碱性去活柱反相高效液相色谱法分析红霉素肟及相关化合物

采用碱性去活（BDS）C18柱分离测定了红霉素肟及相关化合物。以0．02mol／L磷酸氢二钾（用磷酸调pH7．2）-乙腈-甲醇（体积比为50：40：10）为流动相，检测波长为210nm，柱温为35℃。红霉素肟E、Z异构体及相关化合物红霉素A、红霉素A8，9-脱水-6，9-半缩酮和红霉素A6，9-9，12-螺缩酮五种组分分离完全，检测限（S/N=3）为6．0～24．0ng，线性关系良好，方法准确可靠，用于实际样品分析时取得较好的效果。

Flotation performance and adsorption mechanism of novel 1-(2-hydroxyphenyl)hex-2-en-1-one oxime flotation collector to malachite

A novel collector 1-(2-hydroxyphenyl)hex-2-en-1-one oxime(HPHO)was synthesized from 2-hydroxy acetophenone and butyraldehyde.Its flotation performance and adsorption mechanism to malachite were investigated by flotation test,zeta potential,Fourier transform infrared(FTIR)and X-ray photoelectron spectroscopy(XPS)analysis techniques.Compared with benzohydroxamic acid(BA),1-(2-hydroxyphenyl)ethan-1-one oxime(HPEO)and sodium isobutyl xanthate(SIBX),HPHO exhibited excellent collecting power to malachite without additional reagents,such as Na2S regulator and methyl isobutyl carbinol(MIBC)frother.Results of zeta potential indicated that HPHO was coated on malachite surfaces through a chemisorption process.FTIR and XPS data gave clear evidence for the formation of Cu−oxime complex on malachite surfaces after HPHO adsorption through the linkage between C=C,—OH,N—OH group and Cu species.

六氢苯甲酸-环己酮肟联产己内酰胺组合工艺中酰胺液成分的气相色谱-质谱分析

石家庄化纤公司己内酰胺装置是以甲苯为原料,经氧化、加氢、酰胺化、中和、萃取及精制等工序的装置.其基本工艺技术从意大利引进.由于工艺本身的特点,副产物硫铵达3.8吨/吨己内酰胺.该装置设计年产硫氨19万吨,产量较大.……

AmmAmmoximation of Cyclohexanone to Cyclohexanone Oxime Catalyzed by Titanium Silicalite-1 Zeolite in Three-phase System

An innovative green process of producing ε-caprolactam was proposed by integrating ammoximation and Beckmann rearrangement effectively. As a first part of the new process, TS-1 molecular sieve-catalyzed synthesis of cyclohexanone oxime from cyclohexanone, ammonia and hydrogen peroxide was carried out in a batch plant. Cyclohexane was used as the solvent in the three-phase reaction system. The influences of essential process parameters on ammoximation were investigated. Under the reaction conditions as catalyst content of 2.5% (by mass); H 2 O 2 /yclohexanone molar ratio of 1.10; NH 3 /cyclohexanone molar ratio of 2.20; reaction temperature of 343 K; reaction time of 5 h, high conversion of cyclohexanone and selectivity to oxime (both>99%) were obtained. Thus, the three-phase ammoximation process showed equal catalytic activity as TS-1 but much more convenient and simpler for the separation of catalyst in comparison to the industrial two-phase system with t-butanol used as solvent.

Kinetics of Cyclohexanone Ammoximation over Titanium Silicate Molecular Sieves

An intrinsic kinetics of cyclohexanone ammoximation in the liquid phase over titanium silicate molecular sieves is investigated in an isothermal slurry reactor at different initial reactant concentrations, catalyst loading, and reaction temperature. The rate equations are developed by analyzing data of kinetic measurements. More than 10 side reactions were found. H2O2 decomposition reaction must be considered and other side reactions can be neglected in the kinetic modeling. The predicted values of reaction rates based on the kinetic models are almost consistent with experimental ones. The models have guidance to the selection of reactor types and they are useful to the design and operation of reactor used.

An Efficient Solid State Method for Deoximation under Mild Conditions

Oximes of ketones and aldehydes are efficiently converted to the corresponding carbonyl compounds, using a combination of NaHSO4.H20 and paraformaldehyde in good to excellent yields under solid state conditions at room temperature for 10 minutes.

PEG-SO_3H as catalyst for the Beckmann rearrangement and dehydration of oximes

Under mild conditions, conversion of a variety of ketoximes and aldoximes to their corresponding amides and nitriles proceeded in the presence of PEG-SO3H with high yields.

Research Progress in Refining Process for Production of Caprolactam by Beckman Rearrangement Reaction

Caprolactam, which is mainly produced via the Beckmann rearrangement reaction, is an important chemical material. The strict specifications of caprolactam products make the refining process of caprolactam extremely important. According to the different rearrangement process, the refining process of caprolactam is also different. The main refining sequence of liquid phase rearrangement products includes extraction, ion exchange, hydrogenation, and distillation. The refining process of gas phase rearrangement products is conducted mainly through distillation, crystallization, and hydrogenation. In this paper, the research progress of caprolactam refining technology will be summarized according to different rearrangement reaction processes, which will provide a reference for the selection of appropriate caprolactam refining process.

Structure-activity relationships of oxime compounds as flotation collectors by DFT calculations

The relationships between the structure of oxime compounds(R^(1)R^(2)C=NOH,R^(1)/R^(2)=alkyl groups) with different substituents and their corresponding flotation performances were studied. The analyses of density functional theory(DFT) calculations illustrated that the introduced phenyl group at the R^(1) position could enhance the acidity,while the heptyl group could effectively increase the hydrophobicity and benefit van der Waals interactions. Meanwhile,the introduced amino group at the R^(2) position could provide cationic sites to interact with negatively charged surfaces of minerals, while the introduced hydroxyl group could provide additional action sites to form stable chelates with metal ions. Based on the structure-activity relationships, structural optimization was carried out to obtain three efficient collectors, which possessed superior flotation separation performances, proving the effectiveness of the structural modification to oxime compounds in this work.

Synthesis,Crystal Structure and Biological Activities of O-[(Z)-2-Methylbenzyl] 1-Phenyl-2-(1H-1,2,4-triazol-1-yl)ethanone Oxime

The crystal structure of the title compound （C18H18N4O, Mr = 306.36） has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1 with α = 4.783（0）, b = 13.577（1）, c = 13.830（1） A, α = 63.581（2）, β = 88.326（2）, γ = 86.161（2）°, V= 802.5（1） A3, Z= 2, Dc = 1.268 g/cm^3, F（000） = 324, μ（MoKa） = 0.082 mm^-1, the final R = 0.0497 and wR = 0.1199 for 3094 observed reflections （I 〉 2σ（I））. The dihedral angles between the phenyl （C（1）-C（4）-（6）） and triazole, the phenyl （C（13）-C（15）-C（18）） and triazole, and the two phenyl rings are 7.9（1）, 69.9（1） and 67.8（1）°, respectively. Strong C-H…π interaction joins molecules into a chain along the c axis and contributes to the stability of the structure. Preliminary bioassay results show that the title compound possesses excellent and selective fungicidal activity against Colletotrichum gossypii but displays moderate to weak insecticidal activity against aphides.

Brnsted Acidic Ionic Liquids: Efficient and Recyclable Catalytic Systems for Beckmann Rearrangement

Six Brnsted acidic ionic liquids（ILs） 1a―1f were synthesized and used as the dual solvent-catalyst systems for Beckmann rearrangement reactions. Among ILs 1a―1f, IL 1a exhibited the highest catalytic activity and successfully catalyzed the Beckmann rearrangement of ketoximes, and the corresponding amides were obtained in good to excellent yields（74%―92%）. In addition, IL 1a could be recovered easily and reused at least three times without any loss of catalytic activity.

Synthesis and Crystal Structure of (E)-2-phenyl-6,7dihydrobenzofuran-4(5H)-one O-cyanomethyl Oxime

A pair of E/Z-isomers of 2-phenyl-6,7-dihydrobenzofuran-4（5H）-one O-cyanomethyl oxime,C16H14N2O2,as potential drugs for treating peptic ulcer and other acid-related diseases have been synthesized and characterized by IR,MS and NMR spectra.Meanwhile,the crystal of IIIa was obtained and determined by X-ray single-crystal diffraction.Crystal data： monoclinic system,space group P21 /c,a = 8.423（8）,b = 19.596（16）,c = 8.770（8）,β = 107.750（12）°,V = 1379（2）3,Z = 4,F（000） = 560,Dc = 1.283 g/cm3,μ = 0.086 mm 1,R = 0.0681 and wR = 0.2029 for 14472 independent reflections（Rint = 0.0782） and 2428 observed ones（I 2σ（I））.

A Convenient and Efficient Procedure for Oxime Ethers

Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70 - 96%.

Dynamics of novel insecticide HNPC-A9908 residue in vegetable-field ecosystem

HNPC-A9908 （o-（3-phenoxybenzyl）-2-methylthio-1-（4-chlorophenyl） propyl ketone oxime）, a novel oxime insecticide, is a highly effective and broad-spectrum insecticide which can be widely used to control many species of foliar insects on various crops. A study was conducted to evaluate the fate of HNPC-A9908 and study the degradation dynamics of HNPC-A9908 residue in vegetable field ecosystem. The results showed that degradation of HNPC-A9908 was much faster in vegetable pakchoi than in soil, and its half-life in pakchoi and soil was 1.32 and 3.75 d, respectively. The final residue of HNPC-A9908 in pakchoi was at the undetectable level to 0.122 mg/kg. As a conclusion, a dosage of 90 g/hm^2 was suggested and considered to be safe to human beings and animals.

A Mild Oxidant for the Regeneration of Carbonyl Compounds from Oximes in Nonaqueous Condition

Dioxane-NO2 was employed to oxidize oximes to corresponding aldehydes and ketones in high yield in nonaqueous condition at room temperature. Thr reaction proved to be mild and selective.

Synthesis of Novel 1-Alkyl-2-chloro(alkoxy)-1H-indole 3-Carbaldehyde Oximes and Oxime-ethers(esters) Derivatives

A convenient synthesis of 1-alkyl-2-chloro-1H-indole-3-carbaldehyde oximes（5a―5d） and 1-alkyl-2-phenoxy-1H-indole-3-carbaldehyde oximes（6a―6d） from 2-indolone was completed via the Vilsmeier-Haack reac-tion,with N-alkylation and oximation as the key steps.An improved one-pot method for the synthesis of 1-alkyl-2-alkoxy-1H-indole-3-carbaldehyde oximes（7a―7h） from 1-alkyl-2-chloro-1H-indole-3-carbaldehydes（3a―3d） was described.The Williamson reactions and esterification reactions were performed and the oxime-ethers and oxime-esters were synthesized,respectively.The new synthesized compounds（3a―11d） were characterized by 1H NMR,IR,MS,and elemental analysis.

Leukocyte-technetium-99m uptake in Crohn's disease:Does it show subclinical disease?

AIM:To evaluate inflammatory activity in patients with Crohn's disease (CD) using technetium-99m-hexamethylpropyleneamine oxime (99mTc-HMPAO) granulocyte scintigraphy.METHODS: Twenty patients (7 male and 13 female) with CD and five healthy volunteers were selected for 99mTc-HMPAO granulocyte scintigraphy. The Crohn's Disease Activity Index (CDAI), blood tests and C-reactive protein (CRP) of each patient were performed 7 d before the scintigraphic images. The leukocytes were labeled according to the International Society of Radiolabeled Blood Elements (ISORBE) consensus protocol and the scintigraphic images, including single photon emission computed tomography, were obtained 30 min and 2 h after injection of the radiolabeled leukocytes.RESULTS:The labeling yield of the leukocytes with the lipophilic complex 99mTc-HMPAO was 55.0%±10%. Six of the 20 patients (30%) presented congruent results for the three parameters investigated (CDAI, Scintigraphic Index and CRP). On the other hand, 14 patients (70%) did not show congruent results. There was no significant correlation between the indices analyzed according to the Spearman test (P>0.05,n=20).CONCLUSION: The results suggest that 99mTc-HMPAO-labeled leukocyte scintigraphy could be important for determining inflammatory activity in CD even in the absence of clinical symptoms.