Methyl Ketoxime Research Articles

Swapping Copper-Catalytic Process: Selective Access to Pyrazoles and Conjugated Ketimines from Oxime Acetates and Cyclic Sulfamidate Imines.

A powerful CuCl-catalyzed sequential one-pot reaction of aryl methyl ketoxime acetates with cyclic N-sulfonyl imines followed by elimination in the presence of base is reported. This hydrazine-free method conveniently makes C-C and N-N bonds via a radical cleavage of the N-O bond, delivering a special class of C3-hydroxyarylated pyrazoles in good yields. Surprisingly, while employing CuI as a catalyst instead of CuCl, the reaction proceeds through a non-radical pathway which embodies a new tactic for the high-yielding access to value-added conjugated N-unsubstituted ketimines. Moreover, additive-free approach to sulfamidate-fused-pyrazoles was achieved by successfully catalyzing addition and oxidative N-N bond-making reactions by CuI and CuCl, respectively. Significantly, our novel technique could convert the prepared ketimines into the pharmacologically recognized 6H-benzo[c]chromene frameworks.

Palladium-catalyzed decarboxylative ortho-amidation of O-methyl ketoximes with oxamic acids.

The first palladium-catalyzed ortho-amidation of ketoximes has been developed with readily available, easy to handle and environment-friendly N,N-disubstituted oxamic acids as the amidation sources. When N-monosubstituted oxamic acids are used as the substrates, the formed ortho-amidated ketoximes undergo further intramolecular cyclization to provide 3-methyleneisoindolinones.

Tri‐Functional Elemental Sulfur Enabling Bis‐Heteroannulation of Methyl Ketoximes with Methyl N‐Heteroarenes

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Direct synthesis of 2-methylpyridines via I2-triggered [3 + 2 + 1] annulation of aryl methyl ketoxime acetates with triethylamine as the carbon source.

A facile and efficient [3 + 2 + 1] annulation of aryl methyl ketoxime acetates and triethylamine for the synthesis of 2-methylpyridines was disclosed. This reaction demonstrated that I2 was effective in triggering N-O bond cleavage of oxime acetates generating imine radicals. It was noteworthy that this transformation employed triethylamine as the carbon source for the direct formation of pyridines and introduction of methyl groups.

Synthesis and Improvement of Activity of Cobalt Organic Salts as Drier

Organic salts of cobalt were synthesized in the presence of amine, ethanol, and ethyl methyl ketoxime and were used as drier for alkyd resin. Considering the drying time of alkyd resin containing synthesized compound showed that amines, as electron releasing groups (ERG), increased the oxidizing activity of drier and shortened drying time about an hour, whereas ethyl methyl ketoxime delayed the drying of resin 2 hours. Two methods of synthesis, including solution and precipitation processes of synthesis, were compared in terms of convenience, cost, and environmental aspects.

Metabolic oxidation of aralkyl oximes to nitro compounds by fortified 9000g liver supernatants from various species.

Incubation of 'amphetamine oxime' (IIa, anti-benzyl methyl ketoxime) with fortified rabbit liver 9000 g supernatants gave the nitro compound (Ie) and the beta-hydroxylated oxime (IIc) in addition to the previously reported ketone (IIb) and alcohol (Ic) metabolites. Formation of the products was cofactor dependent. The nitro compound was also formed using mouse, hamster and guinea-pig 9000 g liver supernatants and to a minor extent by rat liver. The oximes of 2-phenethylamine (IIe) and norfenfluramine (IIg) were also metabolized to the corresponding nitro compounds, ketones and alcohols with rabbit 9000 g liver supernatants; however, no nitro compound (IIIb) was detected after the incubation of 'mexiletine oxime' (IVa). The metabolic products were identified and characterized by g.l.c., t.l.c. and g.l.c. linked mass spectrometry by comparison with synthetic materials.

Oximate-substituted zirconium alkoxides

The reaction of acetoxime, ethyl methyl ketoxime or cyclohexanone oxime with zirconium iso-propoxide gave dimeric alkoxo oximate derivatives [Zr(OiPr)(oximate)₃]₂. The oximate ligands are side-on coordinated and the alkoxo groups bridge the two metal centres. NMR spectroscopy revealed dynamic behaviour of the compounds in solution. When exposing a reaction mixture of zirconium butoxide and cyclohexanone oxime to ambient moisture, the oxo-alkoxo derivative Zr₄O(OBu)₈(ON=C₆H₁₀)₆ was obtained.

Ketoximate Derivatives of Titanium Alkoxides and Partial Hydrolysis Products Thereof

AbstractCrystalline oximate derivatives of titanium alkoxides [Ti(OR)2(ON=CR′R″)2]2 were obtained when Ti(OR)4 (R = iPr, Et) was treated with various oximes (cyclopentanone oxime, cyclohexanone oxime, acetoxime, ethyl methyl ketoxime or 2,4‐pentandione dioxime). Formation of bis‐substituted derivatives was favored in each case, and only one mono‐substituted derivative, [Ti(OiPr)3(ON=C6H10)]2, was isolated. Two isomers were observed for [Ti(OR)2(ON=CR′R″)2]2, differing by the mutual orientation of the oximate ligands. The NO groups of the oximate ligands are side‐on coordinated to one titanium atom in each case. Three partially hydrolyzed derivatives, viz. Ti6O6(OiPr)6(ON=CR2)6 (CR2 = CMe2 or C5H8) and Ti4O2(OiPr)8(ON=CMe–CH2–CMe=NO)2 were also structurally characterized. In these derivatives the NO groups bridge two titanium atoms.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

O−H Bond Dissociation Enthalpies of Oximes: A Theoretical Assessment and Experimental Implications

By using a multilayer composite ab initio method ONION-G3B3, we calculated O-H bond dissociation enthalpies (BDEs) of 58 oximes that were measured experimentally. Experimental BDEs derived from thermal decomposition kinetics and calorimetric measurements were found to be consistent with the theory. However, the electrochemical method was found to give questionably high BDEs possibly due to errors in the measurement of pKa's or redox potentials. Subsequently, the performances of a variety of DFT functionals including B3LYP, B3P86, B3PW91, BHandH, BHandHLYP, BMK, PBE1PBE, MPW1KCIS, mPWPW91, MPW1B95, and MPW1K were tested to calculate oxime O-H BDEs, where ROBHandHLYP was found to be the most accurate. By using this method, we calculated O-H BDEs of over 140 oximes in a systematic fashion. All of the calculated O-H BDEs fell in the range from 76.8 to 89.8 kcal/mol. An amino group on the azomethine carbon was found to strengthen the O-H bond, whereas bulky alkyl substituents on oximes decreased O-H BDEs due to their large steric-strain-relieving effects in the process of O-H bond cleavage. Para substituents had little effect on the BDEs of benzaldoximes and phenyl methyl ketoximes. Finally, on the basis of a spin distribution calculation, aryl-, alkyl-, and carbonyl-substituted iminoxyl radicals were found to be sigma-radicals, whereas amino-substituted iminoxyl radicals were of pi-structure.

Spiro[4H‐chromene‐4,5′‐isoxazolines] and Related Compounds: Synthesis and Reactivities.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Spiro[4H-chromene-4,5′-isoxazolines] and related compounds: Synthesis and reactivities

Reactions of chromones with methyl ketoximes in the presence of lithium diisopropylamide follow the nucleophilic 1,2-addition mechanism to give spiro[4H-chromene-4,5′-isoxazolines] in good yields. The isoxazoline ring in spiro[4H-chromene-4,5′-isoxazolines] undergoes opening under the action of conc. H2SO4, yielding α,β-unsaturated oximes. Their nitrosation and bromination lead to the corresponding spiroisoxazolines, while the Beckmann rearrangement, to α,β-unsaturated amides. The latter are also formed directly from spiro[4H-chromene-4,5′-isoxazolines] under the action of PCl5. N-Substituted acetophenone hydrazones in the presence of lithium diisopropylamide react at the C(4) atom of 2-trifluoromethylchromone, while acetophenone anil under the same conditions, at the C(2) atom.

Electrochemical Reductions of Ni2+, Cu2+ and Zn2+ Complexes of Azinyl Methyl Ketoximes on Mercury

Electroreductions of Ni2+, Cu2+ and Zn2+ complexes of azinyl (pyridin-2-yl, pyridazin-3-yl, pyrimidin-2-yl, pyrimidin-4-yl, pyrazinyl) methyl ketoximes on mercury electrode were studied using dc polarography. Three different types of complex behavior on the mercury electrode were observed: In the Ni2+ complexes, the hydroxyimino group of the ligand is reduced, whereas in the Cu2+ complexes, the reduction proceeds on the metal ion. With Zn2+ complex of methyl pyridin-2-yl ketoxime, only reduction waves of the uncoordinated ligand and metal were observed due to a rapid decomplexation pre-equilibrium. The structure of [Zn(methyl pyridin-2-yl ketoxime)2(NO3)2], isolated from water-ethanolic solution, was determined by X-ray diffraction. The distorted octahedral coordination sphere around the zinc atom, made up of two pyridine and two oxime nitrogen atoms and two nitrate oxygen atoms, was verified.

ChemInform Abstract: Reactions of Alkyl Methyl Ketoximes with Tetrasulfur Tetranitride Antimony Pentachloride Complex (S4N4×SbCl5): A Regioselective Formation of 3‐Alkyl‐4‐methyl‐1,2,5‐thiadiazoles and Their Mechanism of Formation.

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Reactions of Alkyl Methyl Ketoximes with Tetrasulfur Tetranitride Antimony Pentachloride Complex (S4N4ÅESbCl5): A Regioselective Formation of 3-Alkyl-4-methyl-1,2,5-thiadiazoles and Their Mechanism of Formation

Reactions of Alkyl Methyl Ketoximes with Tetrasulfur Tetranitride Antimony Pentachloride Complex (S4N4ÅESbCl5): A Regioselective Formation of 3-Alkyl-4-methyl-1,2,5-thiadiazoles and Their Mechanism of Formation

Determination of pyrolysis products of smoked methamphetamine mixed with tobacco by tandem mass spectrometry.

This study examines the pyrolysis products of smoked methamphetamine mixed with tobacco that was trapped with a C8 adsorbent cartridge and then detected by gas chromatography-tandem mass spectrometry. According to the results, the mainstream smoke contains 2-methylpropyl-benzene, 2-chloropropyl-benzene, 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, 3-ethyl-phenol, methamphetamine, dimethylamphetamine, hydroquinone, 3-methyl-5-(1-methylethyl)-methylcarbamate phenol, N-methyl-N-(2-phenylethyl)-acetamide, 4-(3-hydroxy-1-butenyl)-3,5,5-trimethyl-2-cyclohexene-1-one, propanoic acid, N-acetylmethamphetamine, phenyl ester, and furfurylmethylamphetamine. In addition, the compounds in sidestream smoke are 2-propenyl benzene, phenylacetone, methamphetamine, dimethylamphetamine, benzyl methyl ketoxime, 3,4-dihydro-2-naphthalenone, N-folmyamphetamine, N-acetylamphetamine, bibenzyl, N-folmylmethamphetamine, N-acetylmethamphetamine, N-propionymethamphetamine, and furfurylmethylamphetamine. Moreover, the presence of methamphetamine promotes the oxidation of the tobacco components.

Metal Ion Chelates of Lipophilic Alkyl Diazinyl Ketoximes as Hydrolytic Catalysts

A series of lipophilic dodecyl hetaryl ketoximes (hetaryl = pyridin-2-yl, pyridazin-3-yl, pyrimidin-2-yl, pyrimidin-4-yl, pyrazin-2-yl as well as their methyl hetaryl homologues was synthesized and hydrolytic activity of their chelates with Co2+, Ni2+, Cu2+ and Zn2+ in a micellar matrix of hexadecyltrimethylammonium bromide or in homogeneous aqueous solutions was investigated using 4-nitrophenyl acetate, 4-nitrophenyl hexanoate and 4-nitrophenyl diphenyl phosphate as model substrates. While Co2+ and Cu2+ chelates are almost inactive, those of Ni2+ and Zn2+ exhibit considerable activity. None of the studied chelates promotes hydrolysis of the used phosphate. The effective species are chelates of the metal : ligand stoichiometry 1 : 3 and 1 : 1 with Ni2+ and Zn2+, respectively, when the ester cleavage proceeds in the micellar matrix. The 1 : 2 stoichiometry was found in aqueous solutions of Ni2+ and Zn2+ chelates of methyl ketoximes.

Equilibrium acidities and homolytic bond dissociation enthalpies ofm- andp-substituted benzaldoximes and phenyl methyl ketoximes

The equilibrium acidities in DMSO of nine p- and m-substituted benzaldoximes and eight p-substituted phenyl methyl ketoximes were measured. Estimates of the homolytic bond dissociation energies (BDEs) of the acidic O—H bonds in these compounds were made by combination of their pKHA values with the oxidation potentials of their conjugate bases, Eox(A−), using the equation BDE = 1.37pKHA + 23.06Eox(A−) + 73.3 kcal (1 kcal = 4.184 KJ). Plots of Eox(A−) vs pKHA for p-substituted benzaldoximes and p-substituted phenyl methyl ketoximes were linear with slopes near unity. Consequently, as required by the above equation, the BDEs estimated for the O—H bonds in these oximes were constant, being 88.3 ± 0.3 and 89.2 ± 0.4 kcal, respectively. © 1998 John Wiley & Sons, Ltd.

Equilibrium acidities and homolytic bond dissociation enthalpies of m‐ and p‐substituted benzaldoximes and phenyl methyl ketoximes

Equilibrium acidities and homolytic bond dissociation enthalpies of m‐ and p‐substituted benzaldoximes and phenyl methyl ketoximes

Microbial transformation of 3,4-methylenedioxy-N-methylamphetamine and 3,4-methylenedioxyamphetamine

The biotransformation of 3,4-methylenedioxy-N-methylarnphetamine (MDMA) and 3,4-methylenedioxyamphetamine (MDA) was examined in the fungus Cunninghamella echinulata. In addition to the reported mammalian metabolites (MDA, 3,4-methylenedioxybenzyl methyl ketoxime, 3,4-methylenedioxybenzyl methyl ketone) and the parent substrate, there were six novel metabolites detected. N-Acetyl-3,4-methylenedioxyamphetamine (NAcMDA) was unequivocally identified and three unidentified metabolites related to NAcMDA were also detected. N-Acetyl-3,4-methylenedioxy-1-phenyl-1-hydroxy-2-aminopropane was tentatively identified as a metabolite of MDMA. The only metabolite of MDA identified was NAcMDA. Two metabolites related to MDA remain unidentified.Key words: Cunninghamella, amphetamine, biotransformation, 3,4-methylenedioxy-N-methylamphetamine, 3,4-methylenedioxyamphetamine.

Metal chelates of heterocyclic nitrogen-containing ketones, X. Synthesis and characterization of platinum(II) complexes of syn-2-picolyl phenyl andsyn-2-picolyl methyl ketoximes. The phenomena of isomerism

Platinum(II) complexes derived from syn-2-picolyl phenyl and syn-2-picolyl methyl ketoximes, LH and L′H, respectively, were synthesised and characterised by elemental analyses, magnetic and molar conductivity measurements and by electronic and vibrational spectroscopic studies. The mode of bonding in these complexes is discussed and their isomerization have been investigated.