Synthesis and investigation of enamine-imine tautomerism of 2,6-disubstituted 4H-1,3-thiazin-4-ones

1982 ◽  
Vol 47 (12) ◽  
pp. 3268-3282 ◽  
Author(s):  
Ján Imrich ◽  
Pavol Kristian
Keyword(s):  
Aromatic Amines ◽  
Mass Spectra ◽  
Secondary Amines ◽  
Alkyl Aryl ◽  
Sodium Hydrosulfide ◽  
H Nmr ◽  
Electron Impact Mass ◽  
Aliphatic Thiols ◽  
Model Substances ◽  
Impact Mass

Substituted thioureas, obtained by reaction of 3-chloro-3-phenylpropenoyl isothiocyanate with primary aliphatic or aromatic amines, were cyclized to 2-N-alkyl(aryl)amino-6-phenyl-4H-1,3-thiazin-4-ones. The enamine-imine tautomerism was investigated by means of infrared and ultraviolet spectra and also by model substances prepared either by reacting the starting isothiocyanate with secondary amines, or by methylation of 2-N-alkyl(aryl)amino-6-phenyl-4H-1,3-thiazin-4-ones. The structure of the synthesized compounds was corroborated by 1H NMR and electron impact mass spectra. 2-N-Arylamino derivatives dissolved in chloroform exist prevalently an imino form whereas 2-N-alkylamino derivatives is an amino form. Reaction of 3-chloro-3-phenylpropenoyl isothiocyanate with aliphatic thiols gave 2-alkylthio-6-phenyl-4H-1,3-thiazin-4-ones and with sodium hydrosulfide (hydroselenide) 6-phenyl-2-thioxo-2,3-dihydro-4H-1,3-thiazin(selenazin)-4-ones.

Synthesis and reactions of substituted benzofuro[3,2-b]pyrrole derivatives

1982 ◽  
Vol 47 (12) ◽  
pp. 3288-3296 ◽  
Author(s):  
Alžbeta Krutošíková ◽  
Jaroslav Kováč ◽  
Miloslava Dandárová ◽  
Mária Bobálová
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Pyrrole Derivatives ◽  
H Nmr ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
C Nmr

This paper deals with the preparation of ethyl benzofuro[3,2-b]pyrrole-2-carboxylate, its hydrolysis, N-alkylation, and reduction. Also the synthesis of new heterocyclic systems, benzofuro[3,2-b]pyrrole and 2H-dihydrobenzofuro[2',3':4,5]pyrrolo[1,2-d]-1,2,4-triazin-1-one, is described. The structure of 14 new substances was corroborated by IR, UV, 1H NMR, 13C NMR and electron impact mass spectra.

New synthesis of 2-amino-4-oxopyrido[3,2-e]-1,3-thiazines and 1-alkyl(aryl)pyrido[3,2-e]-2-thiouracils

1983 ◽  
Vol 48 (11) ◽  
pp. 3315-3328 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Jozef Gonda ◽  
Emília Dandárová
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Secondary Amines ◽  
Primary Amines ◽  
Addition Reactions ◽  
Alkyl Aryl ◽  
H Nmr ◽  
New Synthesis ◽  
Subsequent Cyclization ◽  
C Nmr

Addition reactions of 2-chloronicotinoyl isothiocyanate with primary and secondary amines and subsequent cyclization of intermediate thioureas represent new synthesis of pyrido[3,2-e]thiouracil and pyrido[3,2-e]-thiazine derivatives. 2-Amino-4-oxopyrido[3,2-e]-1,3-thiazines are formed upon heating the reaction components in ethanol, whereas 1-alkyl(aryl)pyrido[3,2-e]-2-thiouracils are products of alkali-catalyzed reaction. In reaction with primary amines the corresponding thioureas were isolated as intermediates, whereas secondary amines reacted directly to give the pyridothiazine derivatives. Structure of the synthesized compounds was confirmed by their 13C NMR and mass spectra; also the IR and 1H NMR spectra are in accord with the suggested formulae.

Mikrobielle Produkte, I NMR-Spektren von Nocardamin und Massenspektrum des Tri-O-methyl-nocardamins / Microbiological Products, I NMR Spectra of Nocardamine and Mass Spectra of Tri-O-methyl-nocardamine

1977 ◽  
Vol 32 (8) ◽  
pp. 937-942 ◽  
Author(s):  
Hubert Maehr ◽  
Wolfgang Benz ◽  
Joanne Smallheer ◽  
Thomas H. Williams
Keyword(s):  
Mass Spectra ◽  
Nmr Spectra ◽  
Silver Oxide ◽  
Electron Impact Mass Spectrometry ◽  
Streptomyces Species ◽  
H Nmr ◽  
Fragmentation Mechanisms ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
C Nmr

Nocardamine was isolated from an unidentified Streptomyces, species X-14568, and its 1H NMR and 13C NMR spectra are assigned in detail. Reaction with iodomethane and silver oxide converts nocardamine to the tri-O-methyl ether which is a suitable derivative for electron-impact mass spectrometry. Fragmentation mechanisms of tri-O-methylnocardamine are discussed.

Synthesis of 2-amino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-thiazines

1983 ◽  
Vol 48 (12) ◽  
pp. 3426-3432 ◽  
Author(s):  
Dušan Koščík ◽  
Pavol Kristian ◽  
Ondrej Forgáč
Keyword(s):  
Spectral Data ◽  
Chlorine Atom ◽  
Mass Spectra ◽  
High Reactivity ◽  
Secondary Amines ◽  
Dimroth Rearrangement ◽  
H Nmr ◽  
New Synthesis ◽  
C Nmr

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.

Notizen: Fast Pulsed Laser Induced Electron Generation for Electron Impact Mass Spectrometry

1988 ◽  
Vol 43 (12) ◽  
pp. 1151-1153 ◽  
Author(s):  
E. R. Rohwer ◽  
R.C. Beavis ◽  
C. Köster ◽  
J. Lindner ◽  
J. Grotemeyer ◽  
...  
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Ion Source ◽  
Electron Impact Mass Spectrometry ◽  
Uv Laser ◽  
Electron Generation ◽  
Medium Resolution ◽  
Electron Impact Mass ◽  
Impact Mass ◽  
Tof Ms

A new ultra fast electron impact (El) ion source is pre­sented that produces a very short, high intensity electron beam, allowing medium resolution mass spectra to be re­corded without pulsing the ion accelerating voltages in a time-of-flight mass spectrometer (TOF-MS). The ion source requires minimum modification of any TOF-MS equipped with an electrostatic ion reflector and UV-laser. El-spectra are presented for comparison with literature spectra.

scholarly journals Combination of LC-MS2 and GC-MS as a Tool to Differentiate Oxidative Metabolites of Zearalenone with Different Chemical Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Andreas A. Hildebrand ◽  
Erika Pfeiffer ◽  
Georg Damm ◽  
Manfred Metzler
Keyword(s):  
Mass Spectra ◽  
Ion Trap ◽  
Hydrolysis Product ◽  
Chemical Structures ◽  
Ion Trap Mass Spectrometer ◽  
Fragment Ions ◽  
Oxidative Metabolites ◽  
Electron Impact Mass ◽  
Negative Electrospray Ionization ◽  
Impact Mass

Recent studies on the mammalian and fungal metabolism of the mycotoxin zearalenone (ZEN) have disclosed the formation of six regioisomers of monohydroxy-ZEN and its reductive metabolite zearalenol (ZEL). Hydroxylation occurs at the aromatic ring or at one of four positions of the aliphatic macrocycle. In addition, an aliphatic ZEN epoxide, its hydrolysis product, and other products were identified in fungal cultures. In this paper, we report the product ion spectra of the [M-H]− ions of 22 oxidative metabolites of ZEN and ZEL, obtained by LC-MS2 analysis using a linear ion trap mass spectrometer with negative electrospray ionization. The MS2 spectra exhibit qualitative and quantitative differences which allow a clear distinction of most metabolites. Moreover, GC-MS analysis of the trimethylsilylated metabolites yields electron impact mass spectra with numerous fragment ions which can be used as fingerprint to confirm the chemical structure derived by LC-MS2 analysis.

ChemInform Abstract: MASS SPECTRA OF NITRONES. ELECTRON IMPACT MASS SPECTRA OF FLUORENONE NITRONES

1981 ◽  
Vol 12 (29) ◽  
Author(s):  
M. A. ABOU-GHARBIA ◽  
D. T. TERWILLIGER ◽  
M. M. JOULLIE ◽  
R. M. SRIVASTAVA
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Electron Impact Mass ◽  
Impact Mass
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