Benzyl Methyl Ketone Research Articles

Studies on Some Organotin (IV) Complexes of Semicarbazones and Thiosemicarbazones

Abstract Some new triphenyltin(IV) complexes with semicarbazones and thiosemicarbazones of the general formula Ph3SnCl.L (L = semicarbazone or thiosemicarbazone of salicylaldehyde, o-hydroxynaphthaldehyde, 2-methoxybenzaldehyde, 4-methoxybenzaldehyde, furfuraldehyde, o-hydroxyacetophenone, benzyl methyl ketone and benzil) have been synthesized and characterised on the basis of elemental analysis, conductance measurements, IR, 1HNMR and electronic spectral studies. An octahedral structure has been proposed for all these complexes.

ChemInform Abstract: Condensation of Salicylaldehyde with Phenylacetone and Ammonia.

AbstractThe reaction between salicylaldehyde (I), benzyl methyl ketone (II) and ammonium acetate (III) yields the products (IV)‐(VI).

The Quantitation of Phenyl-2-Propanone Using High-Performance Liquid Chromatography

Abstract A method using high-performance liquid chromatography (HPLC) has been developed for the rapid, selective, and accurate quantitation of phenyl-2-propanone (P-2-P). A Perkin-Elmer HS/5 C18 column is utilized with a water, methanol, phosphoric acid mobile phase to achieve separation of clandestinely manufactured P-2-P from precursor chemicals and reaction by-products. Absorbance ratio and relative retention time data for some of the more common by-products and precursors are presented.

A study of impurities found in methamphetamine synthesized from ephedrine

The synthesis of methamphetamine from ephedrine via reduction with hydriodic acid is discussed. Impurities which arise from this method are identified and rationalized. The in situ formation of iodoephedrine from ephedrine leads to trace impurities via internal substitution to 1,2-dimethyl-3-phenylaziridine, followed by retro ring-opening and hydrolysis to phenyl-2-propanone (P-2-P). This ketone or the retro ring-opened aziridine further condenses in an aldol condensation followed by dehydration to give 1-benzyl-3-methylnaphthalene and 1,3-dimethyl-2-phenyl-naphthalene. Two-dimensional nuclear magnetic resonance (2-D NMR) was utilized to elucidate the structure of these impurities.

ChemInform Abstract: 2,4,6‐Tri‐tert‐butylphenyllithium as a Base. Kinetic Deprotonation of Benzyl Methyl Ketone.

AbstractThe kinetic deprotonation of benzyl methyl ketone (I) with various lithium bases (II), followed by silylation with (III), is investigated.

ChemInform Abstract: A New Method for the Synthesis of α‐Fluoro and α,α‐Difluoro Benzylic Ketones, Esters and Nitriles.

AbstractAnodic oxidation of the benzyl methyl ketones (I) in acetonitrile in the presence of fluoride gives mixtures of the α‐fluoro ketones (II) and the acetamido derivatives (III).

Conformational preference and internal rotation about the C1—Cα bond in phenylacetaldehyde and some benzyl alkyl ketones from 1H nuclear magnetic resonance and abinitio molecular orbital calculations

Analysis of the 1H nuclear magnetic resonance spectra of the benzyl moieties in phenylacetaldehyde, benzyl methyl ketone, benzyl ethyl ketone, benzyl isopropyl ketone, and 3,5-dichlorobenzyl tert-butyl ketone yields the long-range couplings between ring and α protons. These stereospecific couplings change very little upon replacement of the aldehydic hydrogen by various alkyl groups. The couplings for all the molecules studied fall within the ranges 4J(CH2, Ho) = −0.566 ± 0.008 Hz, 5J(CH2, Hm) = 0.278 ± 0.002 Hz, and 6J(CH2, Hp) = −0.409 ± 0.010 Hz, suggesting that in the ketones the alkyl group prefers to be trans to the phenyl ring and does not interfere with rotation about the C1—Cα bond. The long-range couplings are consistent with a potential function V(θ) = 8.4 ± 1.2 sin2 θ for two-fold rotation about the C1—Cα bond; θ is the angle between the carbonyl and benzene ring plane. Abinitio molecular orbital calculations on phenylacetaldehyde at the STO-3G level with the C=O bond cis to the phenyl group yield a potential of V(θ) = (8.65 ± 0.73) sin2 θ + (1.27 ± 0.80) sin2 2θ, rather close to the experimental potential but with a small fourfold component. The spin–spin coupling constant between the aldehydic and α protons displays a solvent dependence consistent with previously reported values. The insensitivity of 4J(CH2, Ho), 5J(CH2, Hm), and 6J(CH2, Hp) to solvent suggests that [Formula: see text] is very weakly dependent on the rotation of the aldehyde group.

2,4,6-tri-t-butylphenyllithium as a base—kinetic deportonation of benzyl methyl ketone

An extremely bulky lithium reagent, 2,4,6-tri-t-butylphenyllithium, was applied for deprotonation of benzyl methyl ketone to give the kinetic enol ether by “in situ” quenching with chlorotrimethylsilane as the major product indicating that the reagent serves as a hindred base.

Synthesis and phase-transfer property of macrocyclic polythiaether sulphoxides

New macrocyclic polythiaethers with alkylthio side chains have been prepared in good yields starting from 2,6-dithiaspiro[3.3]heptane. The corresponding polysulphoxides were also prepared by the general oxidation method. The macrocyclic polythiaether sulphoxide with benzylsulphinyl side chains was found to be an excellent phase-transfer catalyst which promotes alkylation of benzyl methyl ketone with alkyl halides in a liquid-liquid two-phase system.

A Clandestine Approach to the Synthesis of Phenyl-2-Propanone from Phenylpropenes

Abstract A number of published syntheses for the manufacture of controlled substances appear to be impractical for the average clandestine laboratory. A closer inspection of these syntheses may reveal modifications which greatly simplify their application. An excellent example of this is the preparation of phenyl-2-propanone (P-2-P) from allylbenzene. In the prototype published method, oxygen is introduced into the reaction vessel by using a tank of compressed oxygen with a balloon for a gas reservoir. In our modification, oxidation is accomplished with a 30% hydrogen peroxide solution. P-2-P has been prepared by both methods and a comparison made of the reaction mixtures at various times during their synthesis. Additionally, propenylbenzene, a by-product of these reactions, can be converted to P-2-P by modification of a second synthesis. Gas chromatography and nuclear magnetic resonance spectral data are presented for each method.

Stationary nutations and CIDEP of benzyl radicals during photolysis of methyl benzyl ketone

Abstract Transient benzyl radicals are generated by photolysis of methyl benzyl ketone in toluene solution. Modulation of the rate of radical initiation at 86 kHz causes stationary nutations of the magnetization. They are detected by ESR spectroscopy and used to evaluate the relaxation times as well as the chemically induced dynamic electron polarization of the spin system.

Sulphoxide substituted pyridines as phase-transfer catalysts for nucleophilic displacements and alkylations

2-Methylsulphinyl-, 2-methylsulphinylmethyl-, 2,6-bis(methylsulphinyl)-, 2,6-bis(methylsulphinylmethyl)-pyridines, bis(2-pyridylmethyl) sulphoxide, and 2-methylsulphinylpyridine N-oxide have been prepared. These sulphoxides served as good phase-transfer catalysts which accelerate SN2 type displacements of octyl bromide with various nucleophiles (thiolate, cyanide, thiocyanate, and phenoxide) in solid–liquid two-phase systems. Alkylations of phenylacetonitrile and benzyl methyl ketone with alkyl halides were also carried out in liquid–liquid two-phase systems in the presence of the above sulphoxides to afford the corresponding monoalkylated products in high yields. Pyridine derivatives bearing polysulphinyl groups were found to be even more effective catalysts for these two-phase alkylations. Neither 2-methylthio- nor 2-methylsulphonyl-pyridine catalysed SN2 type displacement reactions effectively.

Chemically induced dynamic nuclear polarization and the mechanism for the photolysis of some dialkyl and aryl alkyl ketones

1. 1H and13C NMR spectroscopy was used to study the photoconversion of methyl n-propyl ketone, methyl benzyl ketone, and methyl adamantyl ketone. The13C and1H CIDNP signs indicated that the polarization arises upon the cleavage of excited ketones in the triplet state. 2. The competition of the radical photodecomposition (Norrish type-I) and “biradical” photodecomposition was studied in the photolysis of methyl n-propyl ketone. The ratio of the probabilities of the two radical pathways (recombination and disproportionation) is 3∶1, while the ratio of the two biradical pathways (photocyclization and Norrish type-II decomposition) is 3∶7. 3. A mechanism was established for the steps in the conversions of the radicals and radical pairs arising in the photolysis of the ketones studied.

Syothesis And Characterisation! of Bis (ThiosEmicarbazonato) Chelates of Cobalt(II), Nickel(II) and Jopper(II)

Abstract Thiosemicarbazones of benzylmethyl ketone and methyl-n-hexyl ketone in their enolic form act as uninegative ligands. In the enolic form, these ligands react with transition metals to form neutral bis-chelates of the type ML2 (where M = Co, Ni and Cu). All the complexed have been characterised by magnetic moment measurement, i.r. and electronic spectral studies, while the copper (II) complexed have also been characterised by ESR spectral studies. The Co(II) complexes may be polymeric six-coordinated species. The Ni(II) and Cu(II) complexes are four-coordinated square planar.

Fungal metabolism of (−)-deprenyl and pargyline

Deprenyl and pargyline were readily metabolized by Cunninghamella echinulata ATCC 9244 and the products obtained were identified by gas-liquid chromatography and mass spectrometry. Deprenyl was completely metabolized to four products; amphetamine, N-methylamphetamine, 1-phenyl 2-propanone oxime and N-acetylamphetamine. Pargyline metabolism extracts contained substrate and five products; N-propargylbenzylamine, N-hydroxy-N-propargylbenzylamine, N-methylbenzylamine, N-acetylbenzylamine and benzylamine. Substrate concentration influenced the relative amounts of metabolites recovered. C. echinulata is an excellent organism for use as a model of mammalian metabolism.

Impurities in Illicit Amphetamine

Reference is made to a peculiar compound, accidentally obtained in the reductive animation of benzyl methyl ketone. The product appears to be degraded by mild heating into cis- and trans-1,5-diphenyl-2-methyl-4-oxopentene-1 and cis- and trans-1,5-diphenyl-2-methyl-4-oxopentene-2, (the structures of which were established by low- and high-resolution mass spectrometry and by 1 H NMR spectroscopy). By means of proton exchange experiments and 1 H NMR spectroscopy the structure of the original compound 2,4-dihydroxy-l,5-diphenyl-4-methyl-pentene-l was found. The structure of a further compound, occurring in minor quantities, 3,4-dihydro-2-benzyl-2-methyl-4-oxo-5-phenyl-2H pyrrole, was established by the same spectroscopic methods. A plausible, but in no way substantiated, route to this compound is suggested.

Reactivity of ketones in homogeneous catalytic hydrogenation with cationic rhodium complexes

The catalytic hydrogenation of several ketones with cationic rhodium complexes has been investigated at 30 °C with hydrogen at atmospheric pressure. The rate of the reaction depended very much on the structure of both the ketone and phosphine ligand, with triethylphosphine giving the highest activity among the ligands used. An electron-withdrawing substituent in the ketone was found to increase its reactivity among both alkyl and aryl ketones; the rates of reaction of the former ketones were generally faster. Benzyl methyl ketone showed a very high reactivity among aryl ketones, suggesting that the phenyl group may be in a position to interact with the rhodium atom to enhance the reactivity. Unsaturated ketones are hydrogenated catalytically to yield saturated ketones first, which are further hydrogenated to corresponding saturated alcohols. No trace of unsaturated alcohol was observed in this hydrogenation, even when the hydrogenation rate of the olefinic bond in the unsaturated ketone was much smaller than that of the carbonyl group of the corresponding saturated ketone in the consecutive hydrogenation. The reactivities of ketones are discussed in connection with their co-ordination and the hydrogenation mechanisms.

Impurities in illicit amphetamine. 7. Identification of benzyl methyl ketone phenylisopropylimine and benzyl methyl ketone benzylimine in amphetamine

The identification of the Schiff bases benzyl methyl ketone phenylisopropylimine and benzyl methyl ketone benzylimine by both high- and low-resolution mass spectrometry is reported. Both substances are found in amphetamine produced illegally by a reductive amination of benzyl methyl ketone.

A novel hydrazine-transfer reaction to a saturated carbon: direct conversion of substituted acetophenone and aliphatic ketone 4-nitrophenylhydrazones into 1,2- bis-hydrazones. Reactions of mercury(II) acetate with nitrogen compounds. Part 6

Treatment of a series of substituted acetophenone 4-nitrophenylhydrazones with mercury(II) acetate in acetic acid gave the corresponding substituted phenylglyoxal bis-(4-nitrophenylhydrazones) in varying yields. Similar reactions involving hydrazine-transfers to methyl groups were observed with the 4-nitrophenylhydrazones of acetone, propiophenone, methyl ethyl ketone, methyl benzyl ketone, and also with the 2,4-dinitrophenylhydrazones of acetone and acetophenone. Substituent influences on product distribution and a possible mechanism are discussed.

Synthesis of substituted thietanes and thiolanes from α- and β-chloroepoxides and their oxidation to 1,1-dioxides

Treatment of 3-chloro-1-phenylpropylene oxide-1,2 (7) or 1-chloro-4-phenylbutylene oxide-3,4 (8) with H2S saturated ethanolic NaOEt gave 3-hydroxy-2-phenylthietane (9) and 3-hydroxy-2-phenylthiolane (10) respectively. A similar treatment of 3-chloro-2-phenylpropylene oxide-1,2 (12) at low temperatures gave 3-chloro-2-hydroxy-2-phenylpropanethiol (13); at reflux temperatures or by refluxing 13 in ethanolic NaOEt, 3-hydroxy-3-phenylthietane (14) was formed.Oxidation of 9, 10, and 14 with m-chloroperbenzoic acid or H2O2–HOAc gave the respective 1,1-dioxides 19, 20, and 25. The alcohols 19 and 20 were dehydrated to their corresponding cyclic olefins through the benzylsulfonate esters. Under the conditions of the Ritter reaction 25 dehydrated to the cyclic olefin. Treatment of 19 with mineral acid gave benzyl methyl ketone, while refluxing 19 in base gave benzyl methyl sulfone. Ethoxylation of 2-phenylthiete 1,1-dioxide (23) to the 3-ethoxy derivative 34 was achieved under basic conditions. Attempted chlorination of 9 resulted in desulfurization to 3-chloropropenylbenzene (5).