Ketone Semicarbazone Research Articles

Synthesis, structure and electrochemistry behavior of a cobalt(III) compound with azide and methyl 2-pyridyl ketone semicarbazone ligands

An unprecedented cobalt(III) compound with methyl 2-pyridyl ketone semicarbazone (HL) and the auxiliary azide ligand, [Co(L)2] [Co(L)(N3)3] (1) was synthesized and further characterized crystallographically and spectroscopically. Compound 1 crystallizes in the triclinic system and space group of P-1 and its structure consists of two mononuclear crystallographic units with metal chromophore comprising two cobalt(III) centers revealing distorted octahedral geometries and formed by distinct ligands in the inner coordination spheres. Interestingly, compound 1 represents the first complex formed by two distinct mononuclear units involving this ligand. As consequence of various donor and acceptor groups in both crystallographic units, there are several strong NH⋯N and NH⋯O hydrogen bonding interactions interconnecting adjacent moieties, ultimately leading to a three-dimensional supramolecular network. Furthermore, the electrochemical behavior of the HL and compound 1 were investigated.

Novel binuclear Cu(II) complexes combining a semicarbazone Schiff base with distinct bridging ligands: Structure and antimicrobial activity

The Schiff base methyl 2-pyridyl ketone semicarbazone (HL) was prepared from the condensation of methyl 2-pyridyl ketone and semicarbazide, and used in the synthesis of a series of novel binuclear Cu(II) complexes with three distinct bridging ligands: [Cu(L)(μ1,1-N3)]2 (1), [Cu(L)(μS,N-SCN)]2 (2) and [Cu(L)(Cl)]2 (3). The compounds were characterized by elemental analysis, IR and UV–Vis spectroscopy, and their solid-state structures have been established by single-crystal X-ray diffraction revealing the first binuclear complexes with the HL ligand. Supramolecular interactions invoving the adjacent complexes were studied in detail. The antimicrobial activity of HL and the complexes 1–3 was further investigated against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Erwinia carotovora and fungals Candida kefyr, Candida krusei and Aspergillus niger, with the complex 3 demonstrating enhanced activity relatively to the free ligand and remaining complexes.

3-(2-Heteroaryl)-pyrazolotetrazoles – a subunits for losartan-like structures

Abstract A modification of biphenylyltetrazole moiety of Losartan (A) by 3-(2-heteroaryl)-pyrazolotetrazole (B) is described. Ketone semicarbazones react with two moles of phosphorus oxychloride-dimethylformamide with the formation of 3-substituted pyrazol-4-carbaldehydes. The transformations of 3-substituted pyrazole-4- carboxaldehydes to 3-substituted pyrazole-4-nitriles were carried out by reaction of hydroxylamine in DMFA. The prepared cyano pyrazoles were converted to tetrazoles by heating with trimethylsilylazide and dibuthyltinoxide in toluene.

Synthesis, and molecular sensing behavior of fac-[Re(CO)3(κ2-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone

When [Re(CO)5Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, fac-[Re(CO)3(κ2-N,N-dpksc)Cl] was isolated. The identity of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] to changes in its surroundings. 1H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl3 and d6-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between fac-[Re(CO)3(κ2-N,N-dpksc)Cl] and its conjugate base, fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl]−. Thermo-optical measurements done on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] disclosed the absence of thermal acid–base inter-conversion between fac-[Re(CO)3(κ2-N,N-dpksc)Cl] and fac-[Re(CO)3(κ2-N,N-dpksc-H)Cl]− and established reversible electronic transfer between the high energy electronic transitions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00×10−10 M can be detected and determined using protophilic solutions of of fac-[Re(CO)3(κ2-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] showed irreversible electrochemical redox process and electrochemically generated product waves pointing to the instability of fac-[Re(CO)3(κ2-N,N-dpksc)Cl] to redox transformations.

Experimental and theoretical assessment of the mechanism involved in the reaction of steroidal ketone semicarbazone with hydrogen peroxide

3β-Acetoxy-5α-cholestan-6-one semicarbazone 1 on reaction with hydrogen peroxide affords selectively 3β-acetoxy-5α-cholestan-6-spiro-1′,2′,4′-triazolidine-3′-one 2. The structural assignment of the product was confirmed by spectral data and elemental analysis. A free radical mechanism of the present reaction was described successfully by calculating theoretical models of 1, A, B and 2, using DFT with B3LYP/6-31G* basis set. It was found that the reaction undergoes through the formation of two radical intermediates and the only one isomer of the product in which –NH–CO– group is cis with respect C5α-H, was selectively obtained. Frontier molecular orbital, spin electronic density, electrostatic potential and atomic charges were discussed.

Spectroscopic and biological studies on newly synthesized nickel(II) complexes of semicarbazones and thiosemicarbazones

Nickel(II) complexes, having the general composition Ni(L) 2X 2, have been synthesized [where L: isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC) and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl −, 1/2SO 4 2−]. All the Ni(II) complexes reported here have been characterized by elemental analyses, magnetic moments, IR, electronic and mass spectral studies. All the complexes were found to have magnetic moments corresponding to two unpaired electrons. The possible geometries of the complexes were assigned on the basis of electronic and infrared spectral studies. Newly synthesized ligand and its nickel(II) complexes have been screened against different bacterial and fungal growth.

Spectroscopic evaluation of manganese(II) complexes derived from semicarbazones and thiosemicarbazones

Manganese(II) complexes having the general composition Mn(L) 2X 2 [where L = isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC) and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl −, 1/2SO 4 2−] have been synthesized. All the complexes were characterized by elemental analyses, molar conductance, magnetic moment susceptibility, EI-mass, 1H NMR, IR, EPR and electronic spectral studies. All the complexes show magnetic moments corresponding to five unpaired electrons. The possible geometries of the complexes were assigned on the basis of EPR, electronic and infrared spectral studies.

EPR, mass, IR, electronic, and magnetic studies on copper(II) complexes of semicarbazones and thiosemicarbazones

Copper(II) complexes having the general composition Cu(L) 2X 2 [where L = isopropyl methyl ketone semicarbazone (LLA), isopropyl methyl ketone thiosemicarbazone (LLB), 4-aminoacetophenone semicarbazone (LLC), and 4-aminoacetophenone thiosemicarbazone (LLD) and X = Cl −, 1/2SO 4 2−] have been synthesized. All the Cu(II) complexes reported here have been characterized by elemental analyses, molar conductance, magnetic moment susceptibility, EI mass, 1 H NMR, IR, EPR, and electronic spectral studies. All the complexes were found to have magnetic moments corresponding to one unpaired electrons. The possible geometries of the complexes were assigned on the basis of EPR, electronic, and infrared spectral studies.

NO3)3Ce]3.H2IO6: AS A VERSATILE AND EFFICIENT REAGENT FOR CLEAVAGE OF CARBON–NITROGEN DOUBLE BONDS UNDER HETEROGENEOUS AND NON-AQUEOUS CONDITIONS

Oximes, hydrazones and semicarbazones of benzylic aldehydes and ketones undergo facile cleavage to the corresponding carbonyl compounds by tris[tri-nitratocerium(IV)]paraperio- date, [(NO3)3Ce]3.H2IO6, in good to high yields.

Tetrabutylammonium Peroxydisulfate in Organic Synthesis; VII. a Facile and Efficient Method for the Regeneration of Carbonyl Compounds from Semicarbazones by Tetrabutylammonium Peroxydisulfate

Semicarbazones of aldehydes and ketones are oxidized to the corresponding carbonyl compounds in excellent yields by tetrabutylammonium peroxydisulfate in dichlorlethane under mild conditions.

Solid State Cleavage of Semicarbazones with Montmorillonite K-10 Supported Bis(trimethylsilyl)chromate under Microwave Irradiation

Semicarbazones of aldehydes and ketones adsorbed on clay can be cleaved oxidatively to the corresponding carbonyl compounds under solvent-free conditions in high yields employing bis(trimethylsilyl)chromate and microwave irradiation.

Reinvestigation of Reaction of cis-Aziridinyl Ketone Semicarbazones and Tosylhydrazones with Diethyl Ether-Boron Trifluoride(1/1)

Reinvestigation of Reaction of cis-Aziridinyl Ketone Semicarbazones and Tosylhydrazones with Diethyl Ether-Boron Trifluoride(1/1)

Hypervalent Iodine in Synthesis; XVI: Regeneration of Carbonyl Compounds from Semicarbazones by Phenyliodine(III) Diacetate (PID)

Semicarbazones of ketones are oxidized to the corresponding parent ketones in good yields by phenyliodine(III) diacetate (PID) in wet acetonitrile under mild conditions

Synthesis and characterization of copper(II) complexes of semicarbazones

Copper(II) complexes of the general composition Cu(ligand) 2X 2 (where X=CI −, Br −, NO − 3, ClO − 4 and 1 2 SO 2− 4) and Cu(ligand) (CH 3COO) 2 have been synthesized with methyl n-pentyl ketone and methyl n-hexyl ketone semicarbazones. All the complexes prepared have been characterized by elemental analysis, magnetic moment, molar conductance, IR, electronic and electron spin resonance spectral studies. The complexes Cu(ligand) 2X 2 (X = Cl −, Br −, NO − 3) and Cu(ligand) (CH 3COO) 2 may have tetragonal geometry, while the complexes Cu(ligand) 2X 2 (X = ClO − 4 and 1 2 SO 2− 4) may be assigned a five-coordinated trigonally distorted square pyramidal geometry.

Stereochemical Studies of Cobalt(II) Complexes of Methyl n-Hexyl Ketone Semicarbazone and Thiosemicarbazone

Abstract Cobalt(II) complexes of the general composition Co(ligand)2X2 (where ligand is methyl n-hexyl ketone semicarba-zone and thiosemicarbazone and X = Cl−, Br−, NO− 3, CH3COO−, SO2 4 −and NCS−) have been synthesised. All the complexes are characterised by elemental analysis, molar conductance, magnetic moments, IR, UV and electron spin resonance spectral studies. All the complexes were found to have magnetic moments corresponding to three unpaired electrons. The possible geometries of the complexes were assigned on the basis of electronic, infrared and ESR spectral studies.

ChemInform Abstract: Photochemistry of Diaryl Ketones. Part 3. Hydrazones, Semicarbazones and Azines as Photoreagents for Fluorene Derivatives.

AbstractAzines, hydrazones and semicarbazones of aldehydes and ketones when photolyzed along with benzophenone afford 1‐hydroxyfluorene.

HPLC of ketone semicarbazones: Relation of the capacity factors of keton semicarbazones to carbon numbers

Journal of High Resolution ChromatographyVolume 11, Issue 8 p. 600-602 Short Communication HPLC of ketone semicarbazones: Relation of the capacity factors of keton semicarbazones to carbon numbers A. Kunugi, A. Kunugi Department of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanSearch for more papers by this authorK. Tabei, Corresponding Author K. Tabei Department of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanDepartment of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanSearch for more papers by this author A. Kunugi, A. Kunugi Department of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanSearch for more papers by this authorK. Tabei, Corresponding Author K. Tabei Department of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanDepartment of Organic Chemistry, Tokyo College of Pharmacy, 1432-1 Horinouchi, Hachioji City, Tokyo 192–03, JapanSearch for more papers by this author First published: August 1988 https://doi.org/10.1002/jhrc.1240110812Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume11, Issue8August 1988Pages 600-602 RelatedInformation

Copper(II) complexes of isobutyl methyl ketone semicarbazone

Copper(II) complexes of isobutyl methyl ketone semicarbazone have been prepared and characterised by magnetic moments, i.r., electronic and e.s.r. spectral studies. The complexes were found to have CuL2X2 and CuL2X2 · 2H2O compositions. The electronic and e.s.r. spectra suggest a five-coordinated trigonal bipyramidal geometry, for the CuL2X2 complexes, (X=Cl−, Br−, NO 3 − , and 1/2 SO 4 2− ) and six-coordinate octahedral geometry has been suggested for CuL2X2 · 2H2O (X=Cl−, Br−, NO 3 − , SO 4 2− ).

Metal chelates of heterocyclic nitrogen containing ketones, Part IX. Magnetic and spectral studies of the dimeric copper(II) complex of 2-picolyl methyl ketone semicarbazone and its ligation by solvent molecules

The preparation and characterization of [(PMKSC-H)Cu]2Cl2 by i.r. electronic and e.s.r. spectra as well as variable temperature magnetic susceptibility are described and a square planar geometry is assumed for the isolated complex. The magnetic susceptibility data indicates overall antiferromagnetic spin coupling. The variable temperature magnetic susceptibility in conjunction with the best fitting procedure yielded: 2J=−46cm−1, g=2.15 and 6=−5 K. E.s.r. data confirm the existence of spin-spin coupling with D=0.0398 cm−1. The g-values obtained from the e.s.r. studies were g11=2.24, g⊥=2.08 and gav.=2.13. The results were used to estimate the Cu-Cu separation in the dimer. The problem of ligation of the dimeric copper(II) complex by various organic solvents was investigated. E.s.r., i.r. and electronic spectra together with the magnetic susceptibiliy studies indicate that [(PMKSC-H)Cu]2Cl2 dissociated in polar solvents to give the adducts [(PMKSC-H)CuLs]Cl which were isolated and characterized.

Ketone or diazoalkane formation from Δ3-1,3,4-oxadiazolin-2-ones. Details of two competing thermolysis mechanisms

The title compounds thermolyse at 50–100 °C in a variety of solvents via two (and only two) competing unimolecular pathways, one producing a diazoalkane and carbon dioxide, the other a ketone, carbon monoxide, and dinitrogen. Diazoalkane formation is favoured by polar solvents and electron-donating substituents, with a Hammett ρ of −1.93 for seven p-substituted 5-methyl-5-phenyloxadiazolinones. Moderate solvent polarity effects, secondary kinetic isotope effects (2.1 ± 0.3% per D for 2b-d6), the Hammett ρ, and Frontier Molecular Orbital Theory, all support concerted diazoalkane formation through a transition state with nonsynchronous bond rupture.Neither decomposition mode shows any correlation with Taft steric parameters, Es, and ketone formation does not correlate with inductive parameters. The enthalpy change during the exothermic three piece fragmentation was calculated to be only −30 ± 2 kcal mol−1, precluding chemiluminescence. A vigorous search for intermediates by esr, ms, CIDNP, trapping, and racemization experiments leads to the conclusion that ketone formation must also be concerted.A new oxidation procedure using lead tetraacetate in the presence of five equivalents of trifluoroacetic acid was useful in the synthesis of oxadiazolinones from ketone semicarbazones which would not cyclize under normal LTA oxidation conditions.