Mass spectrometric studies. XI. Skeletal rearrangements in acylhydrazines

1972 ◽  
Vol 25 (3) ◽  
pp. 523 ◽  
Author(s):  
QN Porter ◽  
AE Seif
Keyword(s):  
Nitrogen Atom ◽  
Alkyl Group ◽  
Phenyl Ring ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
The Other ◽  
Hydrogen Atoms ◽  
Neutral Product ◽  
Skeletal Rearrangements ◽  
Phenyl Compounds

The mass spectra of mono- and di-alkyl-N,N'-dibenzoylhydrazines contain rearrangement ions arising from initial migration of a benzoyl or alkyl group from one nitrogen atom to the other. The spectra also contain ions resulting from N-N fissions accompanied by transfer of one or two hydrogen atoms. The spectra of the mono- and di-phenyl compounds are simpler, but that of the monophenyl compound contains an ion in the formation of which two hydrogen atoms have been transferred to the neutral product from a phenyl ring.

Preparation and 31P NMR characterization of N-bonded complexes of platinum(II) with a phosphadithiatriazine: X-ray structure of trans-PtCl2(Pet3)(η1-N-Ph2PS2N3)

1992 ◽  
Vol 70 (10) ◽  
pp. 2602-2606 ◽  
Author(s):  
Tristram Chivers ◽  
Robert W. Hilts ◽  
Ian H. Krouse ◽  
A. Wallace Cordes ◽  
Randal Hallford ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Free Ligand ◽  
Heterocyclic Ring ◽  
Structural Features ◽  
The Other ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Absorption Bands ◽  
X Ray ◽  
Nmr Characterization

The reaction of Ph2PS2N3 with [Pt2(μ-Cl)2(PEt3)4][BF4]2 or [PtCl2(PEt3)]2, in dichloromethane at 23° C produces the 1:1 adducts cis-[PtCl(PEt3)2(Ph2PS2N3)][BF4], 3, and trans-[PtCl2(PEt3)(Ph2PS3N2)], 4, respectively, in good yields. The 31P NMR data for 3 and 4 indicate that (i) the platinum is attached to a nitrogen atom adjacent to phosphorus in both these adducts, (ii) the PEt3 ligands in 3 are in mutually cis positions, and (iii) the PEt3 ligand in 4 is trans to the heterocyclic nitrogen. These structural features were confirmed by an X-ray analysis of 4. Crystals of 4 are monoclinic, space group P21/c, with a = 14.920(3) Å, b = 8.966(5) Å, c = 19.103(5) Å, β = 109.32(2)°, V = 2411.6(16) Å3, and Z = 4. The least-squares refinement with anisotropic thermal parameters for all non-hydrogen atoms converged at R = 0.050 and Rw = 0.053. The Pt—N bond length is 2.122(15) Å and the coordinated nitrogen atom is lifted ca. 0.63(2) Å out of the plane containing the other heterocyclic ring atoms. The attachment of a platinum(II) centre to the PN3S2 ring perturbs the S—N bond lengths significantly. The S—N distance involving the coordinated nitrogen is 1.672(16) Å, while the other S—N distances are 1.631(19), 1.555(19), and 1.562(19) Å, indicative of a localized sulfur diimide (-N=S=N-) structure. The UV–visible spectra of 3 and 4 in CH2Cl2 exhibit absorption bands at 514 and 528 nm, respectively, but dissociation of these adducts to give the free ligand Ph2PS2N3 occurs readily in dilute solution.

Mass Spectrometric Studies. XIV. Nitrochalcones

1979 ◽  
Vol 32 (10) ◽  
pp. 2249 ◽  
Author(s):  
J Baldas ◽  
QN Porter
Keyword(s):  
Oxygen Transfer ◽  
Mass Spectra ◽  
Nitro Compounds ◽  
Molecular Ions ◽  
Mass Spectrometric ◽  
Hydrogen Atoms ◽  
Carbon Carbon Bond ◽  
Nitro Derivatives ◽  
Anchimeric Assistance ◽  
Hydroxy Groups

The mass spectra of chalcone, of its 2-, 2'-, 3-, 3'- and 4-nitro derivatives, and of a number of deuterated analogues, are described. Fragmentation of the 2-nitro isomer is very simple on account of anchimeric assistance to a carbon-carbon bond fission from the nitro group. The 2'-nitro isomer shows complex fragmentation resulting from oxygen transfer to the α,β-double bond. The 3-, 3'-, and 4-nitro compounds fragment in ways similar to that of chalcone itself, except for losses of hydroxy groups from their molecular ions. The origins of the transferred hydrogen atoms are shown by labelling experiments, and structures are suggested for the ions formed.

scholarly journals Crystal structure of N′-[2-(benzo[d]thiazol-2-yl)acetyl]benzohydrazide, an achiral compound crystallizing in space group P1 with Z = 1

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Rasha A. Azzam ◽  
Galal H. Elgemeie ◽  
Mona M. Seif ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Organic Compound ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
The Other ◽  
Hydrogen Atoms ◽  
Space Group ◽  
Compound C ◽  
C And N

In the molecule of the title compound, C16H13N3O2S, one hydrazinic nitrogen atom is essentially planar, but the other is slightly pyramidalized. The torsion angle about the hydrazinic bond is 66.44 (15)°. Both hydrazinic hydrogen atoms lie antiperiplanar to the oxygen of the adjacent carbonyl group. The molecular packing is a layer structure determined by two classical hydrogen bonds, N—H...O=C and N—H...Nthiazole. The space group is P1 with Z = 1, which is unusual for an achiral organic compound.

Mass spectrometric studies. IX. Benzylidenemalonic esters and related compounds

1971 ◽  
Vol 24 (4) ◽  
pp. 823 ◽  
Author(s):  
QN Porter ◽  
CR Ramsay
Keyword(s):  
Mass Spectra ◽  
Alkoxy Group ◽  
Mass Spectrometric ◽  
Neutral Fragment ◽  
Carbonium Ion ◽  
Skeletal Rearrangements ◽  
Related Compounds

Skeletal rearrangements resulting from alkoxy-group migrations are prominent in the mass spectra of some benzylidenemalonic esters, and involve elimination of C3O2 as a neutral fragment. Similar rearrangements of a chloride atom dominate the mass spectra of benzylidenemalonyl chloride, but migrations of alkyl and aryl groups are unimportant in the mass spectra of structurally related benzylidene β-diketones. The rearrangements observed have been rationalized as the result of a four-centre migration to a carbonium ion centre.

Photochemical and mass spectrometric transformation of gibberellenic acid to 9-epiallogibberic acid

1984 ◽  
Vol 62 (10) ◽  
pp. 1996-1998 ◽  
Author(s):  
Hussain K. Al-Ekabi ◽  
Ghazi A. W. Derwish
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Mass Spectrometric ◽  
The Other ◽  
Positive Mass ◽  
Hydrogen Migration ◽  
Other Hand ◽  
Impact Fragmentation

Gibberellenic acid (2) reacted thermally in a modified immersion photochemical reactor, to give an intermediate triene (3). This triene then isomerized photochemically, via suprafacial [1,3]-hydrogen migration, to 9-epiallogibberic acid (5). On the other hand, comparison of the positive mass spectra of gibberellenic acid (2), allogibberic acid (4), and 9-epiallogibberic acid (5) showed that gibberellenic acid underwent electron impact fragmentation to the triene 3 cation. This cation then rearranged through suprafacial [1,3]-hydrogen migration to the 9-epiallogibberic acid (5) cation.

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

scholarly journals MASS SPECTRA OF SOME FUROQUINOLINE ALKALOIDS

1965 ◽  
Vol 43 (9) ◽  
pp. 2516-2521 ◽  
Author(s):  
D. M. Clugston ◽  
D. B. Maclean
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
The Other ◽  
Methoxyl Group ◽  
Quinoline Ring

The mass spectra of six furoquinoline alkaloids have been recorded and mechanisms have been proposed for their fragmentation upon electron impact. Strong metastable peaks, present in all spectra, have aided in the interpretation of the fragmentation of these alkaloids. The three alkaloids with a methoxyl group in the 8-position of the quinoline ring may be differentiated from the other three by the presence of relatively intense peaks at M-1 and M-29.

Cytokinin activity of some substituted ureas and thioureas

1966 ◽  
Vol 165 (999) ◽  
pp. 245-265 ◽  
Keyword(s):  
Biological Activity ◽  
Active Compound ◽  
Phenyl Ring ◽  
Chemical Structure ◽  
Lower Activity ◽  
Cytokinin Activity ◽  
Hydrogen Atoms ◽  
Detectable Activity ◽  
Low Activity

N , N '-Diphenylurea was shown to have reproducible cytokinin activity . Some 500 ureas, mainly of the N -monosubstituted and N , N '-disubstituted types, were tested an d about one half of these were active. Attempts were made to correlate chemical structure with biological activity. Although there are some exceptions to nearly every generalization it has been possible to formulate some principles. (1) Phenyl urea was the simplest active compound. (2) An HNCONH bridge conferred higher activity than an HNCSNH linkage and any other tested arrangement of the bridge gave inactive com pounds. (3) Compounds in which both amino hydrogen atoms on one or both sides of the bridge were substituted were of low activity or were inactive. (4) Many com pounds of the type R NHCONH 2 in which R = a substituted phenyl ring were tested. Ring substitution generally increased the activity and the highest activity was associated with meta substitution and the lowest with ortho . Compounds with electron-attracting substituents were generally more active than those with electron-donating substituents. Pyridyl compounds were active but com pounds with non-planar rings were inactive. (5) In compounds of the type R NHCONH R ' in which R and R ' were phenyl or substituted phenyl groups the highest activities were usually found in com pounds with one unsubstituted phenyl ring. Those with two substituted phenyl groups generally had lower activity. Some ureas showed detectable activity at 0.1 parts/10 6 . This was about four times less active than kinetin when tested in the tobacco pith assay.

Dative behavior of N-heterocyclic carbenes (NHCs) with selenium in Se-NHC compounds

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Munazzah Yaqoob ◽  
Mahvish Abbasi ◽  
Hira Anwar ◽  
Javed Iqbal ◽  
Mohammad Asad ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Carbon Atom ◽  
Lone Pair ◽  
Heterocyclic Ring ◽  
Heterocyclic Carbenes ◽  
The Other ◽  
Donor Ligands ◽  
Important Research ◽  
Dative Bond ◽  
Back Bonding

Abstract N-heterocyclic carbenes (NHCs) are an eminent class of carbenes having a heterocyclic ring in which a divalent carbon atom is attached directly to a nitrogen atom. In the NHCs, the donation of lone pair is another important research in the dative bonding and not only in NHCs the dative bond plays a functionalized role in the other classes of complex formation like ylidones L → E ← L and carbones L → C ← L. M–NHC bond is L-M sigma-dative bond and NHCs are considered as strong sigma-donor ligands. The clear picture of the M–NHC bond can be better understood by M–NHC pi-interaction. M-L pi interaction is comprised of two steps. One is L → M sigma-donation and M → L π* back bonding. This dative donor nature of NHC and also its behavior in organoselenium is studied through DFT in which it’s optimized structure, bond lengths, molecular vibrations are calculated.

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