Mass spectrometry and structure of ions of heterocyclic compounds activated by collision: Naphthiridines and benzazines

The dissociation and the structure at the isomeric [M — HCN]⁺ and [M — 2HCN]⁺ ions, formed during the fragmentation of naphthiridines and benzazines, were investigated by the collisionally activated dissociation (CAD) method. It was established that the stable [M — HCN]⁺ ions of 1,5- and 1,8-naphthiridines, 1,6-naphthiridine, quinoxaline, and quinazoline have different structures. The [M — 2HCN]⁺ ions can exist in two isomeric forms, one of which is characteristic of naphthiridines and the other of benzazines.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vo. 25, No. 5, pp. 626–629, September–October, 1989.     

Mass-spectrometric study of the cyclization reactions of diazoketones. 8. 1-Diazo-3,4-epoxy-4-arylbutan-2-ones

An analysis of the mass spectra of 1-diazo-3,4-epoxy-4-arylbutanones has shown that the molecular ions of these compounds lose a molecule of nitrogen and that the [M — N₂]⁺ ions formed cyclize to form hydroxyfuran structures, whose further fragmentation determines the whole picture of the dissociative ionization of the compounds investigated under electron impact. The majority of the [M — N₂]⁺ ions have the form of the cyclic intermediate formed in the first step of the cyclization process. It cannot, however, be ruled out that a certain portion of the [M — N₂]⁺ ions are stabilized as a result of a Wolff rearrangement and do not cyclize at all.For report 7 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 17–22, January, 1986.     

Synthesis,configuration, and conformation of 3-acyl derivatives of 3a,4,6,6a-tetrahydrothieno[3,4-d][1,2,3]oxathiazoline 2-oxide

3-Benzoyl-3a,4,6,6a-tetrahydrothieno[3,4-d][1,2,3]oxathiazoline 2-oxide is formed as a result of intramolecular cyclization of cis-4-benzamido-3-chlorosulfitothiophan. Only one sulfur atom — that of the sulfoxide group — is removed from the cyclization product and the analogous 3-methoxycarbonyl-3a,4,6,6a-tetrahydrothieno[3,4-d][1,2,3]oxathiazoline 2-oxide by the action of Raney nickel; the products in this case are, respectively, cis-4-benzamido-3-hydroxythiophan and 3a,4,6,6a-tetrahydrothieno]3,4-d]oxazolidone. The three-dimensional structure of 3-acyl-3a,4,4,6a-tetrahydrothieno[3,4-d][1,2,3]oxathiazoline 2-oxide was determined by ¹H and ¹³C NMR spectroscopy. A difference between the conformational state of 3-substituted 3a,4,6,6a-tetrahydrothieno[3,4-d][1,2,3]oxathiazoline 2-oxides and 3-substituted 3a,4,6,6a-tetrahydrothieno[3,4-d]oxazolidones was established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 191–197, February, 1977.     

Mass spectrometric study of 4-azafluorenes

The dissociative ionization of 4-azafluorene and its methyl and phenyl derivatives was investigated. The relative intensity of the [M — CH₃]⁺ ion peak depends on the position of the CH₃ group in the 4-azafluorene ring. It was established that the loss of an RCN particle (R=H, CH₃, and C₆H₅) for unsubstituted 4-azafluorene takes place from the M⁺ and [M — H]⁺ ion, exclusively from the [M — H]⁺ ion for the methyl-substituted compounds, and from the [M — H]⁺ and [H — 2H]⁺ fragments for the phenyl-substituted derivatives. Randomization of the deuterium ions in the 9,9-d₂-4-azafluorene molecular ion was observed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–250, February, 1978.     

Mass-spectrometric study of 2- and 4-azafluorenones

A mass-spectrometric study of 2- and 4-azafluorenones and their mono- and polymethyl derivatives showed that the presence of a methyl group in the benzene ring leads to a sharp increase in the relative intensity of the [M — H]⁺ ion peak. In contrast to the fragmentation of 2- and 4-azafluorenes, the mass spectra of monomethyl-substituted compounds do not contain an [M — CH₃]⁺ fragment; this is probably associated with expansion of the pyridine or benzene ring to a seven-membered ring in the step involving the formation of the molecular ion due to inclusion of the methyl group. The intensity of the [M — CO]⁺ ion peak in the mass spectra of the 4-azafluorenones is higher by a factor of two with respect to the 2-azafluorenone isomers, and the [M — HCN]⁺ and [M — H, -HCN]⁺ ion peaks observed in the mass spectra of 2-azafluorenones are absent in them.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 89–95, January, 1979.     

Syntheses,crystal structures and magnetic properties of two cyano-bridged two-dimensional assemblies [Fe(salpn)]2 [Fe(CN)5NO] and [Fe(salpn)]2[Ni(CN)4]

Two cyano-bridged assemblies, [Fe^III(salpn)]₂[Fe^II(CN)₅NO] (1) and [Fe^III (salpn)]₂[Ni^II(CN)₄] (2) [salpn = N, N-1,2-propylenebis(salicylideneiminato)dianion], have been prepared and structurally and magnetically characterized. In each complex, [Fe(CN)₅NO]^2– or [Ni(CN)₄]^2– coordinates with four [Fe(salpn)]⁺ cations using four co-planar CN^– ligands, whereas each [Fe(salpn)]⁺ links two [Fe(CN)₅NO]^2– or [Ni(CN)₄]^2– ions in the trans form, which results in a two-dimensional (2D) network consisting of pillow-like octanuclear [—M^II—CN—Fe^III—NC—]₄ units (M = Fe or Ni). In complex (1), the NO group of [Fe(CN)₅NO]^2– remains monodentate and the bond angle of Fe^II—N—O is 180.0°. The variable temperature magnetic susceptibilities, measured in the 5–300 K range, show weak intralayer antiferromagnetic interactions in both complexes with the intramolecular iron(III)iron(III) exchange integrals of –0.017 cm^–1 for (1) and –0.020 cm^–1 for (2), respectively.     

Spezifisch14C-kernmarkierte Phenolderivate, 1. Mitt.: Synthese von [14C]-Guajacol

Zusammenfassung Für oxydative Abbauversuche wurden verschiedene spezifisch¹⁴C-kernmarkierte Phenolderivate benötigt. Guajacol, in verschiedenen Positionen des aromatischen Ringes markiert, wurde — teils von [1-¹⁴C]-Phenol, teils von [2-¹⁴C]-Aceton ausgehend — synthetisiert.

---

Specifically¹⁴C-labelled phenol derivatives, I: Synthesis of [¹⁴C]guaiacol

Various phenol derivatives,¹⁴C-labelled in different specified positions of the aromatic ring, were required for oxidative degradation studies. Guaiacol, ring-labelled in different positions, was prepared both from [1-¹⁴C]phenol and from [2-¹⁴C]-acetone.

---

---

Herrn Prof. Dr.M. Pailer zum 60. Geburtstag in Freundschaft gewidmet.     

The first three aromatic tribromides of the [2.2]paracyclophane series

From the reaction mixtures in the uncatalyzed polybromination of [2.2]paracyclophane by the action of excess Br₂ in CCl₄, there have been found along with the known products — 4,15- and 4,16-dibromo[2.2]paracyclophanes — two new aromatic tribromides of this series, which have been isolated in pure form: 4,12,15- and 4,15,16-tribromo[2.2]paracyclophanes. Special experiments demonstrated that the mixtures of these tribromides are formed as a result of competitive monobromination of 4,15-dibromo[2.2]paracyclophane; the 4,15,16-tribromo[2.2]paracyclophane, together with still another newly isolated isomer of this series — 4,8,12-tribromo[2.2]paracyclophane — is formed as a result of competitive monobromination of 4,16-dibromo[2.2]paracyclophane. As an explanation of the features of the orienting effect of substituents in these competing reactions, a rule was proposed: On the conventional orientation (from the electronic point of view) of entry of the bromine atom into the substituted ring (para > ortho > meta), a steric limitation is imposed on its attack in the pseudo-gem-position, owing to the bulky bromine atom that is transannularly positioned above it in the neighboring aromatic ring. The structures of all of the tribromides were established on the basis of elemental analyses, mass spectrometry, and¹H NMR spectrometry (including PMR using the homonuclear Overhauser effect). The data obtained in this work indicate that the 4,12,15-tribromo[2.2]paracyclophane and 4,15,16-tribromo[2.2]paracyclophane are predecessors of the two tetrabromides previously obtained by Cram — 4,7,12,15- and 4,5,15,16-tetrabromo[2.2]paracyclophanes; and the 4,8,12-tribromo[2.2]paracyclophane is a possible predecessor of 4,8,12,16-tetrabromo[2.2]paracyclophane, which is unknown up to the present time.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1837–1843, August, 1992.     

Mass-spectrometric behavior of isomeric nitro- and nitroaminoindolizines and indoles

Peaks of [M — NO]⁺ and [M — NO₂]⁺ ions are characteristic for the mass spectra of nitroindolizines, whereas peaks of ions of the indole type, viz., [M — HCN]⁺ and [M- H,- HCN]⁺ (for alkylindoles), are not characteristic. In the mass spectra of nitroindoles the latter ions give more intense peaks, while the loss of a nitro group or its rearrangement is a considerably less significant process. When a dialkylamino group is introduced in the nitroindolizine molecule, the primary processes in the fragmentation of such compounds are due to fragmentation of the alkylamino group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 765–768, June, 1982.     

Fragmentation of 2- and 4-(2-furyl) pyridines under the influence of electron impact

The dissociative ionization of 12 compounds of the 2- and 4-(2-furyl)pyridine series that contain methyl, ethyl, and n-propyl groups in various positions of the pyridine ring was investigated. It was established that the intensity of the [M — H]⁺ ion peak depends only slightly on the mutual orientation of the alkyl groups and the furyl grouping, while the probability of cleavage of the furan ring with ejection of CO and HCO particles is very sensitive to these structural factors. Cleavage of the pyridine ring leads to the development of [M — HCN]⁺ and [FuCN]⁺ ions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 769–774, June, 1982.     

Thermal transformations in systems based on zeolites Y,X, and A containing zinc and sodium nitrates

Thermal transformations in systems formed by interaction of Zn and Na nitrates with Y, X, and A zeolites were studied by TG—DTA technique. Temperature regions of existence of adsorbed water, water of crystallization, and decomposition of NO₃ ^– anion were determined. These intervals depend on the composition, structure, method of preparation, and pre-treatment conditions of zeolite systems. The extent of NO₃ ^– decomposition depends not only on the zinc and sodium content but also on the presence of ammonia involved in NO₃ ^– reduction. The zeolite matrix strongly stabilizes the occluded NO₃ ^– anions. A portion of zinc oxide formed by zinc nitrate decomposition is probably localized inside the zeolite cavities as the [Zn—O—(ZnO) _n —Zn]²⁺ particles. The latter compensate charges of the isolated [AlO₄]^– tetrahedra.     

Mass spectrometry and structures of ions of heterocyclic compounds activated by collision. 2. 2-Methylnitroindolizines

The principal pathways of the fragmentation of 2-methylnitroindolizines were investigated. The fragmentation and structures of the isomeric [M-OH]⁺ and [M-NO]⁺ ions formed in the fragmentation of these compounds were studied by the method of dissociative activation by collision (DAC). It was established that the stable [M-OH]⁺ ions formed in the fragmentation of the 1- and 3-nitro isomers as a result of the ortho effect have different structures and that their DAC spectra can be used to determine the position of the nitro group in the molecule.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1631–1635, December, 1988.     

Crown compounds for anions. Sandwich complex of cyclic trimeric perfluoro-o-phenylenemercury with [B12H11SCN]2– anion

The reaction of cyclic trimeric perfluoro-o-phenylenemercury (o-C₆F₄Hg)₃ (1) with the polyhedral [B₁₂H₁₁SCN]^2– anion in THF at 20 °C affords the {[(o-C₆F₄Hg)₃](B₁₂H₁₁SCN)}^2– (4) and {[(o-C₆F₄Hg)₃]₂(B₁₂H₁₁SCN)}^2– (5) complexes. Complex 5 was isolated as the tetrabutylammonium salt. X-ray diffraction analysis showed that this complex has a bent-sandwich structure in which the [B₁₂H₁₁SCN]^2– anion is located between the planes of two molecules 1 and is coordinated to both these molecules through B—H—Hg bridges and S—Hg bonds. The stability constants of complexes 4 and 5 in THF (20 °C), which were determined from the IR spectroscopic data, are 16 L mol^–1 and 992 L² mol^–2, respectively.     

Acetals of lactams and acid amides. XV. Reaction of acetals of N,N-dimethyl- and N-methyl-N-(β-carbethoxyethyl)acetamides with ethyl anthranilate and synthesis of 4-quinolone and 4-quinazolone derivatives

N, N-Dimethyl- and N-methyl-N-(-carbethoxyethyl)-N¹-(o-carbethoxyphenyl) acetamidines were synthesized by reaction of diethylacetals of N, N-dimethyl- and N-methyl-N-(-carbethoxyethyl) acetamides with ethyl anthranilate. The thermal cyclization of these amidines proceeds in different ways — 2-dimethylamino-4-quinolone is formed in the first case, and 2, 3-dimethyl-4-quinazolone is formed in the second.See [1] for communication XIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5 pp. 665–668, May, 1976.     

Synthesis,crystal structure and magnetic properties of a two-dimensional mixed-valence assembly [Fe(salen)]2[Fe(CN)5NO]

A cyanide-bridged Fe^III–Fe^II mixed-valence assembly, [Fe^III(salen)]₂[Fe^II(CN)₅NO] [salen = N,N-ethylenebis(salicylideneiminato)dianion], prepared by slow diffusion of an aqueous solution of Na₂[Fe(CN)₅NO] · 2H₂O and a MeOH solution of [Fe(salen)NO₃] in an H tube, has been characterized by X-ray structure analysis, i.r. spectra and magnetic measurements. The product assumes a two-dimensional network structure consisting of pillow-like octanuclear [—Fe^II—CN—Fe^III—NC—]₄ units with dimensions: Fe^II—C = 1.942(7) Å, C—N = 1.139(9) Å, Fe^III—N = 2.173(6) Å, Fe^II—C—N = 178.0(6)°, Fe^III—N—C = 163.4(6)°. The Fe^II—N—O bond angle is linear (180.0°). The variable temperature magnetic susceptibility, measured in the 4.8–300 K range, indicates the presence of a weak intralayer antiferromagnetic interaction and gives an Fe^III–Fe^III exchange integral of –0.033 cm^–1.     

Ferrocene Compounds. XXVII. Synthesis and Structure of 2-(Ferrocenylmethyl)propane-1,3-diol

The title compound was obtained by reduction of diethyl (ferrocenylmethyl)malonate with lithium aluminium hydride in diethyl ether. The structure of this novel ferrocene derivative was assigned by means of elemental analysis, IR, [¹H]NMR, and [¹³C]NMR spectroscopy. The structure was also confirmed by a single crystal X-ray study. The compound crystallizes in monoclinic P2₁/a space group with unit cell dimensions: a = 9.7360(6), b = 27.040(5), c = 14.767(3) Å, = 103.835(6)°, V = 3774.8(11) ų, Z = 12. The asymmetric unit contains three crystallographically independent molecules. In the ferrocenyl moieties, the Fe–C bond distance values are in the range 2.006(5)—2.051(3) Å and C–C distances in the range 1.366(7)–1.425(4) Å. The cyclopentadienyl rings in each of the molecules are mutually twisted by about 13° from the eclipsed conformation. The hydroxyl groups are involved in the intermolecular O–H...O hydrogen bond formation with O-O distances in the range 2.686(3)–2.801(4) Å forming infinite two-dimensional network in a [0 0 1] plane. The crystal structure is additionally stabilized by C–H-O weak intermolecular hydrogen bonds.     

Investigation of heterocyclic quinones XVII. Oxidative amination of 6-hydroxyquinazoline

Representatives of a new class of heterocyclic quinones — quinazoline-5,6-quinones — were obtained by the oxidative animation of 6-hydroxyquinazoline, 2-phenyl-6-hydroxyquinazoline, and 4-piperidino-6-hydroxyquinazoline. 6-Hydroxyquinazolines that are not substituted in the 2 position are animated in this position during oxidation. A possible mechanism for the amination is proposed.See [1] for communication XVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1698–1702, December. 1971.     

Condensed heterocycles with a thiazole ring.

Derivatives of new condensed heterocyclic systems — pyrido- and quinolino[1,2:3,2]thiazolo[4,5-b]pyrazines — were synthesized by condensation of 2,3-dichloropyrazine with 2-mercaptopyridine and 2-mercaptoquinolines.See [1] for Communicaton 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1276–1278, September, 1990.     

v-Triazolines. part XXI. Spiro[bicyclo[2.2.1]hept-2-ene[54']1',2'.s'-triazole]derivatives from cyclopentadiene and 5-amino-4-methylene-v-triazolines

1R^*, 4R^*, 5S^*, 5'S^*-5'-Amino-1'-(4-nitrophenyl)-4',5'-dihydrospiro[bicyclo [2.2. 1]hept-2-ene[5.4]-1',2',3'-triazoles]$\text{2}$ have been obtained both by ?4 +2]-cycloaddition of cyclopentadiene to amino-methylene-1-(4-nitrophenyl)-4,5-dihydro-v-triazoles $\text{1}$ and by [3+2]-cycloaddition of 4-nitrophenylazide to 5-aminomethylene-2-norborenes $\text{4}$. The configuration has been fully established by X-ray crystallographic analysis. The course of the cycloaddition and the thermal behaviour of $\text{2}$ are discussed.