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.

Synthesis and Pharmacological Activities of Some New 2-[1-Heptyl-3-(4- methoxybenzyl)-5-oxo-1,5-dihydro-4H-1,2,4-triazol-4-yl]acetohydrazide Derivatives

2014 ◽  
Vol 69 (9-10) ◽  
pp. 969-981 ◽  
Author(s):  
Olcay Bekircan ◽  
Emre Mentese ◽  
Serdar Ulker
Keyword(s):  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Lipase Activity ◽  
Spectral Studies ◽  
Antituberculosis Activity ◽  
Pharmacological Activities ◽  
Mass Spectral ◽  
H Nmr ◽  
Acetohydrazide Derivative ◽  
C Nmr

Abstract In the present investigation, the key intermediate acetohydrazide derivative 5 was synthesized starting from 3-(4-methoxybenzyl)-4-amino-4,5-dihydro-1,2,4-triazol-5-one (1) by a four-step reaction. Thiosemicarbazides 6a-f and arylidenehydrazide derivatives 8a-d were obtained from compound 5. The cyclization of compounds 6a-f in the presence of NaOH resulted in the formation of compounds 7a-f. The compounds were characterized by IR, 1H NMR, 13C NMR spectroscopy, elemental analysis and mass spectral studies. The compounds were tested for their anti-lipase, anti-α-glucosidase and anti-mycobacterial activities. Compounds 6b and 8c exhibited excellent anti-lipase activity, and compound 8d showed excellent anti-a-glucosidase activity. Compounds 3 and 4 exhibited good antituberculosis activity

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.

scholarly journals Synthesis of Novel Triazolo[4,3-a]Quinoxaline Darivatives Containing Pyridinyl and Thiazole Nucleous

2015 ◽  
Vol 52 ◽  
pp. 63-73
Author(s):  
Haresh G. Kathrotiya ◽  
Yogesh T. Naliapara
Keyword(s):  
Reaction Time ◽  
Elemental Analysis ◽  
High Yield ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
H Nmr ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
New Compounds ◽  
C Nmr

On pursuing research about [1,2,4] triazolo [4,3-a] quinoxaline, in this paper we report a small library of novel class of [1,2,4] triazolo [4,3-a] quinoxaline derivatives containing pyridinyl thiazole moiety. Particularly valuable features of this method include high yield, broad substrate scope, shorter reaction time and straightforward procedure. The structures of new compounds have been characterized on the basis of elemental analysis, FT-IR, 1H NMR, 13C NMR, and mass spectral data.

scholarly journals Synthesis, Spectral and Anthelmintic Activity Studies on Some Novel Imidazole Derivatives

2008 ◽  
Vol 5 (s2) ◽  
pp. 1133-1143 ◽  
Author(s):  
Rajiv Dahiya ◽  
Anil Kumar
Keyword(s):  
Amino Acids ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Structure Elucidation ◽  
Anthelmintic Activity ◽  
Coupling Agents ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
H Nmr ◽  
C Nmr

Present study describes the synthesis of a novel series of 3,5-diiodo-4-(5-nitro-1H-2-imidazolyl)benzoyl amino acids and di/tri/tetrapeptides using diisopropylcarbodiimide/dicyclohexylcarbodiimide (DIPC/DCC) as coupling agents andN-methylmorpholine/triethylamine (NMM/TEA) as bases. Structure elucidation of all the newly synthesized compounds was done by elemental analysis and IR,1H NMR,13C NMR and mass spectral data. Synthesized imidazolopeptides were screened for their anthelmintic activity and found to possess moderate to good bioactivity against earthwormsMegascoplex konkanensis, Pontoscotex corethruses and Eudrilus eugenieawhen compared to reference drugs - albendazole and mebendazole at dose level of 2 mg mL−1.

scholarly journals An Efficient and Clean Synthesis of Thiophenyl Thiazole Depended Novel Triazolo[4,3-a]Quinoxaline Derivatives

2015 ◽  
Vol 51 ◽  
pp. 125-134
Author(s):  
Haresh G. Kathrotiya ◽  
Sagar P. Gami ◽  
Yogesh T. Naliapara
Keyword(s):  
Schiff Base ◽  
Elemental Analysis ◽  
Room Temperature ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
H Nmr ◽  
Clean Synthesis ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
C Nmr

A simple and efficient approach for the synthesis of thiophenyl thiazole based triazolo [4,3-a] quinoxaline derivatives is described. In this methodology, 3-hydrazinyl-N-(4-(thiophen-2-yl) thiazol-2-yl) quinoxalin-2-amine derivatives treated with various aromatic aldehyde to form Schiff base which on treatment with iodobenzene diacetate in dichloromethane at room temperature to furnish title compounds. The synthesized compounds were characterized by 1H NMR, 13C NMR, FT-IR, elemental analysis, and mass spectral data

scholarly journals Synthesis of some New Quinoxalines Bearing Pyridinyl Thiazole Moiety

2015 ◽  
Vol 52 ◽  
pp. 74-83
Author(s):  
Haresh G. Kathrotiya ◽  
Yogesh T. Naliapara
Keyword(s):  
Elemental Analysis ◽  
Condensation Reaction ◽  
Mass Spectral Data ◽  
Structural Class ◽  
Mass Spectral ◽  
H Nmr ◽  
Chemical Structures ◽  
Quinoxaline Derivatives ◽  
Ft Ir ◽  
C Nmr

Keeping the objective to build up a new structural class of quinoxaline, a new series of quinoxaline derivatives bearing the pyridinyl thiazole nucleus have been synthesized by base-catalyzed chloro-amine condensation reaction approach. The protocol offers expeditious and easy synthesis with excellent yield. The chemical structures of the synthesized compounds were elucidated by 1H NMR, 13C NMR, FT-IR, elemental analysis, and mass spectral data.

scholarly journals Synthesis of Novel Highly Substituted Pyrimidines Bearing Furanyl Thiazole Nucleous

2015 ◽  
Vol 60 ◽  
pp. 47-57
Author(s):  
Haresh G. Kathrotiya ◽  
Yogesh T. Naliapara
Keyword(s):  
Elemental Analysis ◽  
Aromatic Aldehydes ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
H Nmr ◽  
Chemical Structures ◽  
Ketene Dithioacetals ◽  
Guanidine Nitrate ◽  
Ft Ir ◽  
C Nmr

A series of novel highly substituted pyrimidines bearing furanyl thiazole nucleous have been synthesized. In which reaction of guanidine nitrate with ketene dithioacetals 3c produced substituted pyrimidines 4d which further treated with various aromatic aldehydes to afford title compounds 5(a-t). The chemical structures of the synthesized compounds were elucidated by 1H NMR, 13C NMR, FT-IR, elemental analysis, and mass spectral data.

Efficient and convenient synthesis of pyrido [2,1-b]benzothiazole, pyrimidopyrido[2,1-b]benzothiazole and benzothiazolo[3,2-a][1,8]naphthyridine derivatives

2015 ◽  
Vol 21 (4) ◽  
pp. 219-224 ◽  
Author(s):  
Hala M. Refat ◽  
Khaled S. Mohamed
Keyword(s):  
Spectral Data ◽  
Elemental Analysis ◽  
Aromatic Aldehydes ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Benzothiazole Derivatives ◽  
H Nmr ◽  
Convenient Synthesis ◽  
C Nmr

AbstractNew 3-aryl-pyrido[2,1-b][1,3]benzothiazole derivatives 2a–e were synthesized in excellent yields via the reaction of benzothiazoleacetonitrile (1) with different aromatic aldehydes. The treatment of 2-(benzo[d]thiazol-2-yl)-3-(pyridin-4-yl)acrylonitrile (6) with malononitrile afforded 1-amino-3-(pyridin-4-yl)-3H-pyrido[2,1-b][1,3]benzothiazole-2,4-dicarbonitrile (7), which was allowed to react with a variety of reagents to provide pyrimido[5′,4′:5,6]pyrido[2,1-b][1,3]benzothiazole 8, 9 and [1,3]benzothiazolo[3,2-a][1,8]naphthyridine 10, 15 derivatives. All synthesized products were confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral data.

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.

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