scholarly journals Synthesis of Some Heterocyclic Compounds Derived from 2-Mercapto Benzoxazole

2013 ◽  
Vol 10 (3) ◽  
pp. 766-778 ◽  
Author(s):  
Baghdad Science Journal

New series of 2-mecapto benzoxazole derivatives (1-20) incorporated into fused to different nitrogen and suphur containing heterocyclic were prepared from 2-meracpto benzoxazole, when treated with hydrazine hydrate to afford 2-hydrazino benzoxazol (1). Compound (1) converted to a variety of pyridazinone andphthalazinone derivatives (2-4) by reaction with different carboxylic anhydride. Also, reaction of (1) with phenyl isothiocyanate and ethyl chloro acetate afforded 3-phenyl-1,3-thiazolidin-2,4-dione-2-(benzoxazole-2-yl-hydrazone) (6). Azomethines (7-10) were prepared through reaction of (1) with aromatic aldehyde, then (7, 8) converted to thaizolidinone derivatives (11, 12). Treatment of (1) with active methylene compounds afforded derivative (13). Reaction of (1) with CS2 and NaOH gave 1,2,4-triazole derivative (14). Treatment of (1) with p-bromophenancyl bromide afforded another 1,2,4-triazole (15). The reaction of 2-mercapto benzoxazole with chloro acetic acid gave (16) followed by refluxing (16) with ortho-amino aniline giving benzimidazol (17). Moreover, the reaction of 2-mercapto benzoxazole with ethyl chloroacetate afforded (18), and then reaction of (18) with thiosemicarbazide and 4% NaOH leads to ring closure giving 1,2,4-triazole derivative (20). All compounds were confirmed by their melting point, FT-IR, UV-Vis spectra and 1H-NMR spectra for some of them.

2010 ◽  
Vol 7 (2) ◽  
pp. 1014-1022
Author(s):  
Baghdad Science Journal

In this work 2-hydrazino pyrimidine (1) was prepared from 2-mercapto pyrimidine with hydrazine hydrate. Treatment of (1) with active methylene compounds gave 2-(3,5-dimethyl -1 H – Pyrazole-1-yl) pyrimidine , whereas the reaction of (1) with carboxylic anhydride namely maleic anhydride or 1,2,3,6-tetra hydro phthalic anhydride yielded 1-Pyrimidine-2-yl-1,2-dihydro pyridazine-3,6-dione (3) and 2 – Pyrimidin -2-yl -2,3,4 a ,5,8 a – hexahydro phthalazine 1,4 – dione (4) . Reaction of (1) with phenyl isothiocyanate and ethyl chloro acetate afforded 3-Phenyl-1,3-thiazolidine-2,4-dione-2( pyrimidine -2- yl hydrazone (6) Azomethine (7-10) were prepared through condensation of (1) with aromatic aldehydes or ketones, then compounds (7-9) are converted into a number of tetrazole derivatives (11-13). Treatment of (1) with acetic acid afforded the derivative (14) . The reaction of 2-mercapto pyrimidine with ethyl chloro acetate afforded (15),whereas the reaction of (15) with thiosemicarbazide and 4% sodum hydroxide leads to ring closure giving 1,2,4 triazole derivative (17). Moreover the reaction of 2-mercapto pyrimidine with chloro acetic acid gave (18) followed by refluxing (18) with o- amino aniline to give the benzimidazole derivative (19).the structure of these compounds were characterized by FR-IR, UV spectra and some of them were characterized by element analysis.


Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2925 ◽  
Author(s):  
Joshua Gavin ◽  
Joel Annor-Gyamfi ◽  
Richard Bunce

Quinazolin-4(3H)-ones have been prepared in one step from 2-aminobenzamides and orthoesters in the presence of acetic acid. Simple 2-aminobenzamides were easily converted to the heterocycles by refluxing in absolute ethanol with 1.5 equivalents of the orthoester and 2 equivalents of acetic acid for 12–24 h. Ring-substituted and hindered 2-aminobenzamides as well as cases incorporating an additional basic nitrogen required pressure tube conditions with 3 equivalents each of the orthoester and acetic acid in ethanol at 110 °C for 12–72 h. The reaction was tolerant towards functionality on the benzamide and a range of structures was accessible. Workup involved removal of the solvent under vacuum and either recrystallization from ethanol or trituration with ether-pentane. Several 5,6-dihydropyrimidin-4(3H)-ones were also prepared from 3-amino-2,2-dimethylpropionamide. All products were characterized by melting point, FT-IR, 1H-NMR, 13C-NMR, and HRMS.


2021 ◽  
Vol 13 (1) ◽  
pp. 183-194
Author(s):  
T. Saroja ◽  
R. M. Ezhilarasi ◽  
V. Selvamani ◽  
S. Mahalakshmi

Heterocyclic compounds such as pyrazolines, pyrimidines, oxazole and isoxazole exhibit different pharmacological activities. The current study involves synthesis of new 2-pyrazolines. The synthesis involves the cyclocondensation reaction of substituted chalcones with (4-fluorophenylthio)acetic acid hydrazide (FTAH) under reflux. The chalcones (C1-C7 / 1a-1g) were synthesized from the reaction of substituted acetophenone with substituted benzaldehyde and FTAH was prepared from 4-fluro thiophenol. New 2-pyrazolines were obtained in good yields (60-70 %). All the compounds were characterized by FT-IR, 1H, 13C NMR and mass spectra. PASS analysis was carried out for the 2-pyrazolines synthesized (P1-P7 / 3a-3g).


2019 ◽  
Vol 16 (3) ◽  
pp. 405-412 ◽  
Author(s):  
Ahmed A.O. Abeed ◽  
Talaat I. El-Emary ◽  
Mohamed S.K. Youssef

<p>Aim and Objective: This work presents the synthetic capability and the exploitation of 1,3-diphenyl- 1H-pyrazole-4-carboxladehyde 1 and 5-diphenyl pyrazolyl-2-pyrazoline analogue 8 to serve as excellent precursors for the synthesis of substituted indol-2,3-dione, trizolo[3,4-a]benzazoles, thiazolo[2,3- a]benzimidazole-3-one, substituted 2-pyrazoline and pyrazole-substituted-pyrazolines using various reagents. </P><P> Materials and Methods: Using chemicals from Aldrich, Fluka, or Merck, and pure solvents, we apply the synthetic procedures for the synthesis of novel heterocycles. The melting points of these compounds were determined using APP. Digital ST 15 melting point apparatus. SP3-100 spectrophotometer recorded FT-IR spectra (KBr) (cm-1). NMR spectra (&#948;, ppm) were recorded on 400 MHz AVANCE-III High-Performance FT-NMR Spectrometer BRUCKER (Switzerland) and some 1H NMR spectra were recorded on Varian EM-360L NMR Spectrophotometer (90 MHz) (USA) in CDCl3 or DMSO-d6 as a solvent. Elemental analyses were carried out at a Vario EL C, H, N, and S Analyzer. Bromine was determined using direct titration method after carius combustion. </P><P> Results: The structures of the compounds were confirmed by IR, 1H NMR, 13C NMR, and elemental analyses. </P><P> Conclusion: 1,3-Diphenyl-1H-pyrazole-4-carboxladehyde 1 and 2-pyrazoline derivative 9 confirmed their importance in the synthetic organic chemistry. Depending on the formyl group of aldehyde 1 and active methylene of pyrazoline 8, we synthesized new series of heterocycles; indol-2,3-dione, trizolo[3,4-a]benzazole, thiazolo[2,3-a]benzimidazole-3-one and pyrazolyl-pyrazoline derivatives expecting their pharmacological applications. The targeted compounds were substantiated from its spectral data.</p>


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5168
Author(s):  
Joel K. Annor-Gyamfi ◽  
Ebenezer Ametsetor ◽  
Kevin Meraz ◽  
Richard A. Bunce

An efficient synthetic route to highly functionalized naphthalenes and quinolines has been developed using domino reactions between Morita–Baylis–Hillman (MBH) acetates and active methylene compounds (AMCs) promoted by anhydrous K2CO3 in dry N,N-dimethylformamide (DMF) at 23 °C. The substrates incorporate allylic acetates positioned adjacent to a Michael acceptor as well as an aromatic ring activated toward a SNAr ring closure. A control experiment indicated that the initial reaction was an SN2’-type displacement of a side chain acetoxy by the AMC anion to afford the alkene product bearing the added nucleophile trans to the SNAr aromatic ring acceptor. Thus, equilibration of the alkene geometry of the initial product was required prior to cyclization. Products were isolated in good to excellent yields. Numerous cases (24) are reported, and several mechanistic possibilities are discussed.


2019 ◽  
Vol 70 (11) ◽  
pp. 3769-3774
Author(s):  
Elena Valentina Rosca ◽  
Theodora Venera Apostol ◽  
Constantin Draghici ◽  
Octavian Tudorel Olaru ◽  
Laura Ileana Socea ◽  
...  

This paper presents the synthesis of new heterocyclic compounds from oxazoles and triazinones classes. Some 2-(4-(4-X-phenylsulfonyl)benzamido)acetic acids were condensed with 4-iodobenzaldehyde in presence of acetic anhydride and sodium acetate, when the new corresponding unsaturated oxazol-5(4H)-one were obtained. Through the reaction of these oxazol-5(4H)-ones with phenylhydrazine, in presence of the acetic acid and sodium acetate, the new heterocyclic compounds from 1,2,4-triazin-6(5H)-ones class were obtained. The structures of synthesized compounds have been confirmed by spectral methods (FT-IR, 1H-NMR, 13C-NMR and MS) and elemental analysis. The cytotoxicity of the compounds was evaluated using the Daphnia magna and Artemia salina bioassays.


2019 ◽  
Vol 70 (11) ◽  
pp. 3769-3774
Author(s):  
Elena Valentina Rosca ◽  
Theodora Venera Apostol ◽  
Constantin Draghici ◽  
Octavian Tudorel Olaru ◽  
Laura Ileana Socea ◽  
...  

This paper presents the synthesis of new heterocyclic compounds from oxazoles and triazinones classes. Some 2-(4-(4-X-phenylsulfonyl)benzamido)acetic acids were condensed with 4-iodobenzaldehyde in presence of acetic anhydride and sodium acetate, when the new corresponding unsaturated oxazol-5(4H)-one were obtained. Through the reaction of these oxazol-5(4H)-ones with phenylhydrazine, in presence of the acetic acid and sodium acetate, the new heterocyclic compounds from 1,2,4-triazin-6(5H)-ones class were obtained. The structures of synthesized compounds have been confirmed by spectral methods (FT-IR, 1H-NMR, 13C-NMR and MS) and elemental analysis. The cytotoxicity of the compounds was evaluated using the Daphnia magna and Artemia salina bioassays.


2011 ◽  
Vol 64 (11) ◽  
pp. 1530 ◽  
Author(s):  
Ran Jiang ◽  
Xue-Qiang Chu ◽  
Xiao-Ping Xu ◽  
Bin Wu ◽  
Shun-Jun Ji

α-functionalization of ferrocenyl alcohols by direct C–O bond activation by indoles, active methylene compounds, electron-rich arenes, anilines, alcohols, and thiols in acetic acid is described. This protocol provides a relatively green and efficient combinatorial access to ferrocene derivatives in a metal-free manner.


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