N-Benzylidene-2-nitrobenzenesulfenamide and 1-Nitro-2-(phenylthio)benzene: Comparison of Their Behavior on Flash Vacuum Pyrolysis and Under Electron Impact

1990 ◽  
Vol 43 (10) ◽  
pp. 1779 ◽  
Author(s):  
RG Gillis ◽  
QN Porter ◽  
LL Yeoh
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Preparative Thin Layer Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Base Peak ◽  
Pyrolysis Products ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Electron Impact Mass ◽  
Layer Chromatography

The molecular ion of N-benzylidene-2-nitrobenzenesulfenamide (1) loses SO2 and N2 and gives a base peak at m/z 165, C13H9, and another abundant peak at m/z 166, C13H10. Analysis, by gas chromatography/mass spectrometry and by preparative thin-layer chromatography, of the products of flash vacuum pyrolysis at 500-800°C of (1) showed no detectable hydrocarbon, but dibenzothiophen (mol. wt 184) was isolated and identified. The abundance of m/z 184 in the positive-ion mass spectrum of (1) is about 1%. In the mass spectrum of 1-nitro-2-( phenylthio )benzene (2a) the base peak is at m/z 167, C12H9N, and there is a fragment ion at m/z 184, C12H8S (35%). However, carbazole (3) could not be isolated from the flash vacuum pyrolysis products, but dibenzothiophen (4) was obtained in increasing yield as the pyrolysis temperature was raised from 500 to 800°C. It is clear from these results that drawing analogies between electron impact mass spectra and flash vacuum pyrolysis results is somewhat hazardous.

The Behavior of 1-Phenyl-2-benzimidazolinethione and 1-Phenyl-2-benzimidazolinone upon Electron Impact and Pyrolysis

1974 ◽  
Vol 52 (13) ◽  
pp. 2359-2366 ◽  
Author(s):  
Denis C. K. Lin ◽  
Michael L. Thomson ◽  
Don C. DeJongh
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Mass Spectra ◽  
Path Loss ◽  
Starting Material ◽  
Base Peak ◽  
Pyrolysis Products

The mass spectra of 1-phenyl-2-benzimidazolinethione (3) and 1-phenyl-2-benzimidazolinone (4) have been compared with their pyrolysis products and similarities have been found. In the 70 eV mass spectrum of 3, the base peak results from the loss of H•; at low ionizing voltages, this path and a competing path, loss of S, are the only ones which remain. At 650° in a stream of N2, 1-phenylbenzimidazole (8, 20%) formed from the loss of S and benzimidazo-[2,1-b]benzothiazole (5, 11%) formed by loss of H2. The major fragmentation paths in the mass spectrum of 4 are loss of CHO• and NCO•. At 950°, phenazine (6, 35%) formed by loss of CH2O, and carbazole (7, 14%) formed by loss of HNCO. In each pyrolysis, 65–70% of the starting material was recovered or accounted for.

Some reactions of 2-ethenyl-4,4-Ethylenedioxy-1-methylcyclohex-1-ene prepared by pyrolysis of 5,5-Ethylenedioxy-7a-methyl-4,5,6,7-tetrahydro-2H-inden-1(7aH)-one

1984 ◽  
Vol 37 (11) ◽  
pp. 2295 ◽  
Author(s):  
RFC Brown ◽  
GL Burge ◽  
DJ Collins
Keyword(s):  
High Pressures ◽  
Preparative Thin Layer Chromatography ◽  
Major Product ◽  
Diels Alder ◽  
Lewis Acid Catalysts ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Layer Chromatography ◽  
Mild Hydrolysis ◽  
Hydrolysis Of

Flash vacuum pyrolysis of 5,5-ethylenedioxy-7a-methyl-4,5,6,7-tetrahydro-2H-inden-1(7aH)-one (2) at 630� gave a good yield of 2-ethenyl-4,4-ethylenedioxy-1-methylcyclohex-1-ene (6), but at 740� p-cresol was the major product. The diene acetal (6) was also obtained by pyrolysis of 5,5-ethylene- dioxy-lβ-hydroxy-7a-methyl-1,2,5,6,7,7a-hexahydro-4H-indene-1α-carbonitrile (3) at 600�. Pyrolytic reactions of 7a-methyl-2,3,7,7a-tetrahydro-1H-indene-1,5(6H)-dione (1), 5,5-ethylenedithio-7a- methyl-2,3,5,6,7,7a-hexahydro-1H-inden-1-one (7) and of 1,1-ethylenedioxy-3,5,5-trimethylcyclohex- 3-ene (8) are also described. Mild hydrolysis of the diene acetal (6) afforded 3-ethenyl-4-methylcyclohex-3-en-1-one (9) which upon brief treatment with dry hydrogen chloride in chloroform at 0� gave, after preparative thin-layer chromatography, a low yield of pure 3-ethenyl-4-methylcyclohex-2-en-1-one (11). The diene acetal (6) failed to undergo Diels-Alder reactions, even at high pressures with Lewis acid catalysts, and it reacted anomalously with two molecules of 4-phenyl-1,2,4-triazoline-3,5-dione; the isomeric diene acetal 1-ethenyl-3,3-ethylenedioxy-6-methylcyclohex-1-ene (18) gave the expected Diels-Alder adduct with this reagent.

Electron Impact Mass Spectroscopy for Identification of Phencyclidine

1986 ◽  
Vol 69 (5) ◽  
pp. 814-820
Author(s):  
Charles C Clark
Keyword(s):  
Mass Spectrum ◽  
High Resolution ◽  
Electron Impact ◽  
Mass Spectroscopy ◽  
Phenyl Ring ◽  
Labeled Compounds ◽  
Electron Impact Mass ◽  
High Resolution Mass Spectroscopy ◽  
Impact Mass ◽  
Resolution Mass

Abstract The electron impact mass spectrum of phencyclidine (PCP) was studied using both deuterium-labeled analogs and high-resolution mass spectroscopy. The deuterium-labeled compounds used were d5.PCP having 5 deuterium atoms on the phenyl ring, d10.PCP having 10 deuterium atoms on the cyclohexyl ring, and d15.PCP having deuterium atoms on both the phenyl and cyclohexyl rings. The identities of some major fragments and some possible pathways for their formation are shown. Electron impact mass spectroscopy is shown to be a definitive test for the identification of PCP.

Antifungal Antibiotic from the Mushroom Agrocybe aegerita (BRIG.) SING.

1992 ◽  
Vol 57 (3) ◽  
pp. 590-603 ◽  
Author(s):  
Karel Stránský ◽  
Marta Semerdžieva ◽  
Miroslav Otmar ◽  
Želimír Procházka ◽  
Miloš Buděšínský ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Performance ◽  
Preparative Thin Layer Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Agrocybe Aegerita ◽  
Antifungal Antibiotic ◽  
Antibiotic Compounds ◽  
Structural Formulae ◽  
Layer Chromatography

An extract from a submersed culture of the mushroom Agrocybe aegerita (BRIG.) SING., containing antifungal antibiotic compounds was chromatographed on a silica gel column. Compounds from fractions which displayed the highest biological activity were concentrated and isolated by means of preparative thin-layer chromatography and preparative high-performance liquid chromatography, and were further characterized by means of gas chromatography, mass spectrometry and nuclear magnetic resonance. They are sesquiterpenic diols predominantly with an illudine skeleton. Structural formulae are proposed for some of them.

Spectres de masse d'hydrazino-2 benzo- et naphtothiazoles et d'hydrazones des méthyl-3 benzo- et naphtothiazolinones-2

1975 ◽  
Vol 53 (23) ◽  
pp. 3677-3680 ◽  
Author(s):  
Jean-Claude Richer ◽  
Philippe Lapointe ◽  
Martine Beljean ◽  
Michel Pays
Keyword(s):  
Mass Spectrum ◽  
Mass Spectra ◽  
Base Peak ◽  
Molecular Ion ◽  
Ion Fragmentation ◽  
Fragment Ions ◽  
Sampling Probe ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
Hydrazone Form

Electron impact mass spectra are reported for the hydrazones of 3-methyl-2-benzothiazolinone (1), of 4-, 5-, 6-, and 7-chloro-3-methylbenzo-2-thiazolinones (2, 3, 4, and 5) and of 3-methyl-naphtho[2,1-d]-2-thiazolinone (6), as well as for 2-hydrazinobenzothiazole (7), for 4-, 5-, 6-, and 7-chloro-2-hydrazinobenzothiazoles (8, 9, 10, and 11) and for 2-hydrazinonaphtho[2,1-d]thiazole (12). The results obtained in the two series are compared. The 2-hydrazone and 3-methyl-benzo-2-thiazolinone and its derivatives all form a base peak corresponding to the molecular ion; fragmentation proceeds mainly by successive losses of·NH2, HCN, HCN, and then CS. Initial losses of N2H2, NH·, and NH3 are minor fragmentation routes.In the case of 2-hydrazinobenzothiazole and its derivatives, the base peak is still that of the molecular ion; however, the relative proportions of the various fragment ions vary with the position of sampling probe inside the apparatus. Thus it is concluded that the observed mass spectrum is that of a mixture of the possible hydrazone-hydrazine tautomers. The principal fragmentations involve the initial loss of NH3 (leading to a stabilized ion), of NH2· (probably from the hydrazone form), and of N2H2.(Journal Translation)

The remarkable electron impact mass spectrum of (2-benzyl-1,3-xylylene)-15-crown-4: expulsion of triethylene glycol by double hydrogen transfer

1996 ◽  
pp. 925 ◽  
Author(s):  
Gert-Jan M. Gruter ◽  
Ben L. M. van Baar ◽  
Tom J. Gerrits ◽  
Otto S. Akkerman ◽  
Friedrich Bickelhaupt ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Hydrogen Transfer ◽  
Triethylene Glycol ◽  
Electron Impact Mass Spectrum ◽  
Electron Impact Mass ◽  
Double Hydrogen ◽  
Impact Mass

Methyleneketenes and methylenecarbenes. I. Formation of arylmethyleneketenes and alkylideneketenes by pyrolysis of substituted 2,2-Dimethyl-1,3-dioxan-4,6-diones

1974 ◽  
Vol 27 (11) ◽  
pp. 2373 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
KJ Harrington
Keyword(s):  
Liquid Nitrogen ◽  
Liquid Nitrogen Temperature ◽  
Pyrolysis Products ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Infrared Measurements

Flash vacuum pyrolysis (430�) of 5-benzylidene-2,2-dimethyl-1,3-dioxan- 4,6-diones gives benzylidene-ketenes which dimerize to form 2,4- bis(benzylidene)cyclobutane 1,3-diones. Diphenylmethylene-,t- butylmethylene- and isopropylidene-2,2-dimethyl-1,3-dioxan-4,6-diones similarly give the substituted methylene ketenes which dimerize to form 2,4-bis(diphenylmethylene)-, 2,4-bis(t-butylmethylene)- and 2,4- bis(isopropylidene)-cyclobutane-1,3-dione respectively. Infrared measurements on the pyrolysis products kept at liquid nitrogen temperature showed absorption near 2100 cm-1 which was attributed to the methyleneketenes. Reaction of the pyrolysates of ethylidene- and isobutylidene-2,2-dimethyl-1,3-dioxan-4,6-diones with aniline vapour yielded but-3-enanilide and 4-methylpent-3-enanilide respectively.

Spectrométrie de masse du chloro-1 diméthoxy-2,6 naphtalène; comparaison de données théoriques et expérimentales

1983 ◽  
Vol 61 (9) ◽  
pp. 2089-2091 ◽  
Author(s):  
Jean-Claude Richer ◽  
Simone Odiot
Keyword(s):  
Mass Spectrum ◽  
Electron Impact ◽  
Electron Impact Mass Spectrum ◽  
Relative Stabilities ◽  
Spectrométrie De Masse ◽  
Electron Impact Mass ◽  
Impact Mass

In an unambiguous manner we have synthesized 1-chloro-2,6-dimethoxy-d3-naphthalene (5) and examined its electron impact mass spectrum. We report here calculations on the relative stabilities of 1-chloro and 5-chloro-6-methoxy-2-naphthols (4a and 4b) and on the relative stabilities of the O—CH3 bond in the 2 and 6 positions of compound 5. [Journal translation]

Behaviour of Cyclopropanes Bearing Capto-Dative Substitution Upon Electron-Impact and Flash-Vacuum Pyrolysis Conditions

2010 ◽  
Vol 98 (8) ◽  
pp. 529-546 ◽  
Author(s):  
Lin-Zhi Chen ◽  
Robert Flammang ◽  
André Maquestiau ◽  
Wayiza Masamba ◽  
Robert Merényi ◽  
...  
Keyword(s):  
Electron Impact ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis
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