2-Amino-substituted derivatives of benzimidazoles from 2-isothiocyanato carboxylates

1989 ◽  
Vol 54 (1) ◽  
pp. 206-214 ◽  
Author(s):  
Ľubomír Floch ◽  
Michal Uher ◽  
Ján Leško
Keyword(s):  
Spectral Methods ◽  
Mass Spectral ◽  
Derivatives Of ◽  
C Nmr

2-Isothiocyanato carboxylates react with o-phenylenediamine to give N,N'-substituted thioureas, which cyclize to yield 2-amino-substituted derivatives of imidazole. The structure of these compounds was corroborated by IR, UV, 1H, 13C NMR, and mass spectral methods.

Synthesis of isothiocyanates from non-aromatic nitrogen-containing heterocycles

1986 ◽  
Vol 51 (1) ◽  
pp. 112-117 ◽  
Author(s):  
Jozef Gonda ◽  
Pavol Kristian ◽  
Ľubomír Mikler
Keyword(s):  
Spectral Methods ◽  
Mass Spectral ◽  
H Nmr ◽  
C Nmr

Investigation of the reaction of thiophosgene with Δ2-oxazolines I, Δ3-thiazolines II, 4H-benzo[d][1,3]thiazines III, 2-methoxypentahydro-Δ1-azepine IV, theophylline and caffeine showed that only compounds I and IV reacted to give 2-acyloxyethyl isothiocyanates and methyl 6-isothiocyanatohexanoate. The structure of these products was corroborated by IR, 1H NMR, 13C NMR and mass spectral methods. The suitability of the above-mentioned compounds to react is discussed.

Synthesis and antimicrobial properties of N-substituted derivatives of (E)-2′,3″-thiazachalcones

2015 ◽  
Vol 70 (1-2) ◽  
pp. 45-50
Author(s):  
Asu Usta ◽  
Hacer Taşkıran
Keyword(s):  
Elemental Analysis ◽  
Antimicrobial Properties ◽  
Antibacterial Activities ◽  
Spectral Studies ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mass Spectral ◽  
H Nmr ◽  
Derivatives Of ◽  
C Nmr

Abstract N-alkyl substituted 2′,3″-thiazachalcones {3-[(1E)-3-(4-methylthiophene-2-yl)-3-oxoprop-1-en-1-yl]-1-alkyl (C5–12,14) pyridinium bromides} were synthesized by a two-step reaction. The newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, elemental analysis and mass spectral studies. The synthesized compounds were tested for antibacterial activities and found to be more active against Gram-positive as compared to Gram-negative bacteria.

Synthetic Utility of 2-Benzylidene-1,2,3,4-tetrahydrocarbazol-1-ones. A Facile Syntheses of Pyrano[2,3-a]carbazoles, Pyrido[2,3-a]carbazoles and Pyridazino[3,4-a]carbazoles

2005 ◽  
Vol 70 (2) ◽  
pp. 223-236 ◽  
Author(s):  
Isravel Antony Danish ◽  
Karnam Jayarampillai Rajendra Prasad
Keyword(s):  
Elemental Analysis ◽  
Spectral Methods ◽  
Mass Spectral ◽  
H Nmr ◽  
Synthetic Utility ◽  
C Nmr

2-Benzylidene-1,2,3,4-tetrahydrocarbazol-1-ones 1, synthons easily accessible from the corresponding 1,2,3,4-tetrahydrocarbazol-1-ones, were utilized in the synthesis of fused carbazoles. In accordance, the reaction of 1 with malononitrile yielded pyrano[2,3-a]carbazoles 2a and 2d or pyrido[2,3-a]carbazoles 2b, 2c and 2e. The reaction of 1 with thiocarbohydrazide or thiosemicarbazide under basic conditions afforded pyridazino[3,4-a]carbazoles 3 or thiol substituted pyridazino[3,4-a]carbazoles 4, respectively, in good yields. The formation of the hitherto unknown compounds was well supported by plausible mechanisms. The products formed were characterized by IR, 1H NMR, 13C NMR, mass spectral methods and by elemental analysis.

Thermal cyclocondensations of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino derivatives of 2-propenoic acid

1987 ◽  
Vol 52 (12) ◽  
pp. 2918-2925 ◽  
Author(s):  
Viktor Milata ◽  
Dušan Ilavský
Keyword(s):  
Uv Spectra ◽  
Propenoic Acid ◽  
Amino Derivatives ◽  
Derivatives Of ◽  
C Nmr ◽  
Ir And Uv Spectra

The cyclization of 3-N(4- and 5-benzimidazolyl and benztriazolyl)amino-2-cyano- and 2-ethoxycarbonyl-2-propenoate esters Ia, b-IVa, b under the conditions of the Gould-Jacobs reaction leads to angularly ring-fused substituted imidazo or triazolo[4,5-f] (V, VI) and [4,5-h] (VII, VIII) quinolines, respectively. The esters Vb-VIIIb have been transformed into the corresponding chloroderivatives Vc-VIIIc. 3-N(5-Benzimidazolyl and 5-benztriazolyl)amino-2-cyano-2-propenenitriles are cyclized in the presence of aluminium(III) chloride to give the aminoquinolines Vd, VId. The structure of the products has been characterized by their 1H, 13C NMR, IR, and UV spectra.

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

scholarly journals A New Cucurbitane Glycoside from Siraitia grosvenorii

2015 ◽  
Vol 10 (9) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Venkata Sai Prakash Chaturvedula ◽  
Srinivasa Rao Meneni
Keyword(s):  
High Resolution ◽  
Phytochemical Study ◽  
Mass Spectral ◽  
High Resolution Mass ◽  
Siraitia Grosvenorii ◽  
Commercial Extract ◽  
Resolution Mass ◽  
C Nmr

A systematic phytochemical study of the commercial extract of Luo Han Guo ( Siraitia grosvenorii) resulted in the isolation of an additional minor new cucurbitane glycoside, mogroside V A1 (1). The structure of the new compound was characterized on the basis of 1D (1H and 13C NMR) and 2D (COSY, HMQC, HMBC and NOESY) NMR and high resolution mass spectral (HRMS) data, as well as hydrolysis studies.

Triazolopyridine nucleosides. II. Glycosylations of 3-oxo-s-triazolo[4,3-a]pyridines with accompanying conversions into 2-oxo-s-triazolo[1,5-a]pyridine nucleosides

1977 ◽  
Vol 55 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Brian Maurice Lynch ◽  
Suresh Chandra Sharma
Keyword(s):  
General Structure ◽  
Spectroscopic Properties ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
H Nmr ◽  
Pyridine Nitrogen ◽  
Methyl Derivatives ◽  
Fragmentation Patterns ◽  
Ribose Moiety ◽  
C Nmr

3-Oxo-s-triazolo[4,3-a]pyridine and various C-methyl derivatives (general structure 1) have been converted into the 2-β-D-ribofuranosyl species 2 and thence 4 via Friedel–Crafts catalyzed reaction with tetra-O-acetyl-β-D-ribofuranose, followed by deblocking. During the course of these reactions, rearrangements into the isomeric 3-β-D-ribofuranosyl-2-oxo-s-triazolo[1,5-a]-pyridines occur through ring-opening of the pyridine rings yielding species 3 and 5. The proportion of rearrangement products is dependent upon the position and number of the C-methyl substituents.Structural assignments for these compounds are based upon comparisons of spectroscopic properties (1H nmr, 13C nmr, uv) with model compounds from each isomeric series; structural assignments for these models are based on unequivocal mass-spectral fragmentation patterns. Unlike related triazolopyridine nucleosides with the ribose moiety attached to a pyridine nitrogen (Lynch and Sharma (1976)), there are no unusual aspects in the conformations of the nueleosides of types 4 and 5.

An Elegant Synthetic Route to 3-Cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles

2004 ◽  
Vol 59 (1) ◽  
pp. 106-108 ◽  
Author(s):  
Isravel A. Danish ◽  
Karnam J. R. Prasad
Keyword(s):  
Elemental Analysis ◽  
Spectral Methods ◽  
Title Compound ◽  
Sodium Hydride ◽  
Synthetic Route ◽  
Mass Spectral ◽  
Plausible Mechanism

Abstract 2-Benzylidene-1-oxo-1,2,3,4-tetrahydrocarbazoles (1a - e) obtained from the corresponding 1- oxo-1,2,3,4-tetrahydrocarbazoles on reaction with malononitrile in dry benzene with sodium hydride afforded 3-cyano-5,6-dihydro-2-ethoxy-4-phenyl-pyrido[2,3-a]carbazoles (2a - e) in good yields. A plausible mechanism for the formation of the title compound has been proposed and all the compounds were characterised by IR, NMR, mass spectral methods and elemental analysis.

scholarly journals Interaction of Fullerenes with Organosilanes in the Ionization Chamber of a Mass Spectrometer under Electron Impact and the Reaction of C60with Tetraphenylsilane in Solution under UV Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Yury I. Lyakhovetsky ◽  
Elena A. Shilova ◽  
Alexandra P. Pleshkova ◽  
Alexander I. Belokon ◽  
Sergey O. Yakushin ◽  
...  
Keyword(s):  
Electron Impact ◽  
Mass Spectrometer ◽  
Uv Irradiation ◽  
Ionization Chamber ◽  
Ion Source ◽  
Organic Radicals ◽  
Mechanistic Study ◽  
Mass Spectral ◽  
Additional Support ◽  
Derivatives Of

C60was shown to react with organosilanes Me4Si, Ph2SiH2, Ph2MeSiH, Ph4Si, andα-naphthylphenylmethylsilane in the electron ionization ion source of a mass spectrometer with the transfer of the corresponding organic radicals (Me, Ph, andα-naphthyl) from the silanes to the fullerene. The reactions were accompanied by hydrogen addition to some products and hydrogen loss from them. C70reacted with Me4Si analogously. A reaction mechanism involving homolytic dissociation of the silanes under electron impact to the corresponding organic radicals, which react further with C60at the surface of the ionization chamber of the mass spectrometer to give the respective adducts, was offered. A mechanistic study of the reaction of C60with Me4Si supported it. No silicon containing derivatives of the fullerenes were found. C60reacted with Ph4Si in solution under UV irradiation in a similar fashion furnishing phenyl derivatives of the fullerene. These results provide an additional support to the hypothesis formulated earlier thatthe homolytic reactive mass spectrometry of fullerenes (the reactions of fullerenes with other species in the ionization chambers of mass spectrometers and their mass spectral monitoring)can predict the reactivity of them toward the same reagents in solution to a significant extent.

Preparation of 2,3-Dideoxy-2,3-epimino and 3,4-Dideoxy-3,4-epimino Derivatives of 1,6-Anhydro-β-D-hexopyranoses by Mitsunobu Reaction

1998 ◽  
Vol 63 (6) ◽  
pp. 813-825 ◽  
Author(s):  
Jiří Kroutil ◽  
Tomáš Trnka ◽  
Miloš Buděšínský ◽  
Miloslav Černý
Keyword(s):  
Nmr Spectra ◽  
Mitsunobu Reaction ◽  
Derivatives Of ◽  
C Nmr

A series of new 2-, 3- and 4-benzylamino-2-, 3- and 4-deoxy derivatives of 1,6-anhydro-β-D-hexopyranoses were prepared from 1,6:2,3- and 1,6:3,4-dianhydro-β-D-hexopyranoses by treatment with benzylamine and converted into 2,3-(N-benzylepimino)-2,3-dideoxy- and 3,4-(N-benzylepimino)-3,4-dideoxy-β-D-hexopyranoses of the D-allo, D-galacto and D-talo configuration by Mitsunobu reaction. The structures of benzylamino and benzylimino derivatives were confirmed by 1H and 13C NMR spectra.

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