Synthesis of 2-methyl-3-(5-phenyl or 1,5-diphenyl-2-pyrazolin-3-yl)-1,8-naphthyridines

1988 ◽  
Vol 53 (7) ◽  
pp. 1543-1548 ◽  
Author(s):  
Maringanti Thirumala Chary ◽  
Kaleru Mogilaiah ◽  
Bathula Sreenivasulu

3-Cinnamoyl-2-methyl-1,8-naphthyridines II have been synthesized utilizing Claisen-Schmidt condensation of 3-acetyl-2-methyl-1,8-naphthyridine I with aromatic aldehydes. The cinnamoyl naphthyridines react with hydrazine hydrate and phenylhydrazine to create the corresponding pyrazolinyl 1,8-naphthyridine derivatives (III and IV). The structures II-IV have been confirmed by their elemental analyses and spectral data. Some of the compounds have been screened for their fungicidal activity.

2014 ◽  
Vol 10 ◽  
pp. 808-813 ◽  
Author(s):  
Dileep Kumar Singh ◽  
Mahendra Nath

A synthetic protocol for the construction of new meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins is described starting from 5-(4-amino-3-nitrophenyl)-10,15,20-triphenylporphyrin. The reaction of this porphyrin with 2,5-dimethoxytetrahydrofuran, followed by the reduction of the nitro group in the presence of NiCl2/NaBH4 afforded 5-(3-amino-4-(pyrrol-1-yl)phenyl)-10,15,20-triphenylporphyrin. This triphenylporphyrin underwent a Pictet–Spengler cyclization after the reaction with various aromatic aldehydes followed by in situ KMnO4 oxidation to form target porphyrin analogues in good yields. The structures of all synthesized products were established on the basis of spectral data and elemental analyses.


1989 ◽  
Vol 54 (6) ◽  
pp. 1716-1720 ◽  
Author(s):  
Gurram Rama Rao ◽  
Kaleru Mogilaiah ◽  
Bathula Sreenivasulu

2-(4-Aryl-2-pyrazolin-3-yl)-1,8-naphthyridines III have been prepared by the cycloaddition of diazomethane to 2-styryl-1,8-naphthyridines II. The structures of the compounds have been confirmed by elemental analyses and spectral data. All these compounds have been screened for fungicidal activity.


2018 ◽  
Vol 15 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Ghada S. Masaret ◽  
Thoraya A. Farghaly

Aim and Objective: Enaminones belay to be extremely stable compounds and constitute a versatile group of salutary precursors for the synthesis of enormous classes of organic compounds. So, in this context, we synthesized a new enaminone, namely, (E)-3-(dimethylamino)-1-(8-phenyl-8H-[1,2,4]triazolo[4,3- a]perimidin-10-yl)prop-2-en-1-one (enaminone 2). Materials and Methods: The reaction of enaminone 2 with different types of hydrazonoyl chlorides or hydrazine hydrate afforded new substituted pyrazoles. Also, the reaction of enaminone with 6-amino-2- thioxopyrimidin-4-one in acetic acid under reflux produced 2-thioxopyridopyrimidinone derivative. The latter thione derivative reacts with hydrazonoyl chlorides to give pyridotriazolopyrimidines. 5-(8-Phenyl-8H- [1,2,4]triazolo[4,3-a]perimidin-10-yl)isoxazole was produced from the reaction of enaminone 2 with hydroxylamine. Results & Conclusion: The structure of all the novel perimidine derivatives was confirmed on the basis of spectral data and elemental analyses. The enaminone and the newly synthesized compounds were tested for their antimicrobial activity, and the results obtained revealed that some derivatives are more potent than the reference drugs used.


2008 ◽  
Vol 4 (3) ◽  
pp. 548-553 ◽  
Author(s):  
M. A. El-Hashash ◽  
Yaser Abdel-Moemen El-Badry

The behavior of  2-ethoxycarbonyl-4H-3,1-benzoxazin-4-one and its behavior towards nitrogen nucleophiles namely, hydrazine hydrate, formamide, benzylamine, ethylamine, piperidine, ethanol amine, o-phenylenediamine, and glucosamine hydrochloride has been investigated. Also the reaction of 3-[aminoquinazolin-4(3H)-one-2-yl]formic acid hydrazide with aromatic aldehydes and phenylisothiocyanate has been discussed. The structure of the prepared compounds are elucidated using physical and spectral data like, FT-IR, 1HNMR, and mass spectroscopy.


2019 ◽  
Vol 35 (2) ◽  
pp. 822-828
Author(s):  
Cong Tien Nguyen ◽  
Dao Thi Hong Dinh ◽  
Thin Van Nguyen ◽  
Giang Duc Le ◽  
Hien Cao Nguyen

4-Chlorobenzylidene-2-methyl-(4H)-oxazol-5-one, which were prepared from 4-chlorobenzaldehyde and acetylglycine in reaction with hydrazine hydrate in ethanol gave 1-amino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-one. However, treatment of 4-chlorobenzylidene-2-methyl-(4H)-oxazol-5-one with hydrazine hydrate in pyridine yielded 3-(4-chlorophenyl)propanohydrazide. Reaction of 1-amino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-one with aromatic aldehydes gave eight corresponding Schiff’s bases namely 1-arylideneamino-4-(4-chlorobenzylidene)-2-methyl-1H-imidazolin-5(4H)-ones. The structure of the 3-(4-chlorophenyl)propanohydrazide and the imidazoline-5-one compounds was confirmed by IR, 1H-NMR and MS spectral data. The Schiff’s bases were tested for antimicrobial activities against several strains of Gram-positive, Gram-negative bacteria, molds and yeasts.


2012 ◽  
Vol 9 (4) ◽  
pp. 1801-1809 ◽  
Author(s):  
Ashvin D. Panchal ◽  
Pravinkumar M. Patel

The Series of N-(5-(Substituted phenyl)-4,5-dihydro-1H-pyrazol-3-yl)-4H-1,2,4-triazol-4-amine compounds were prepared by reaction of 4-amino-1,2,4-Triazole with Acetyl Chloride followed by different aromatic aldehydes and cyclization with hydrazine hydrate. The structures of new compounds were confirmed by IR and1H-NMR spectral data. Anti-bacterial and Anti-fungal activities were evaluated and compared with the standard drugs, some compounds of the series exhibited promising anti-microbial and anti-fungal activity compared to standard drugs.


2011 ◽  
Vol 8 (2) ◽  
pp. 541-546 ◽  
Author(s):  
S. Sridhar ◽  
S. C. Dinda ◽  
Y. Rajendra Prasad

A series of new chalcones(3a-g)were prepared by Claisen-Schmidt condensation of 3-acetyl-2,5-dimethylfuran with various substituted aromatic aldehydes in presence of aqueous solution of potassium hydroxide and ethanol at room temperature. The synthesized chalcones were characterized by means of their IR,1H NMRspectral data and elemental analyses. When these chalcones were evaluated for antimicrobial and anti-inflammatory activities, some of them were found to possess significant activity, when compared to standard drugs.


2020 ◽  
Vol 17 ◽  
Author(s):  
W. Abd El-Fattah

: In this work, 1,2,4-triazine derivatives were synthesized and evaluated for anticancer activities. Series of 1,2,4-triazine derivatives (4a, b) were prepared via the reaction of N-benzoyl glycine (1) with aromatic aldehydes in presence of fused sodium acetate and acetic anhydride to give 1,3-oxazolinone derivatives (2a, b), followed by condensation with 1-(ethoxycarbonyl) hydrazine (3) in glacial acetic acid. Compounds (4a, b) then reacted with acetic anhydride, ethyl chloroacetate and 2,4-dinitrophenyl hydrazine yielded the corresponding to N-acetyl derivatives (5a, b), N-(ethoxycarbonyl) methyl derivative (6) and 1,2-disubstituted hydrazine (7), respectively. The structures of the 1,2,4-triazine derivatives were confirmed by IR, 1H, 13C NMR, MS and elemental analyses. Anticancer activity of some 1,2,4-triazine derivatives (4-7) have been investigated. The results revealed that compounds 4a (IC50= 2.7μM), 5a (IC50= 1.5μM), and 5b (IC50= 3.9μM) show promising inhibitory growth efficacy compared to a standard antitumor drug (IC50= 4.6μM). These three compounds can be considered as potential agents against human hepatocellular carcinoma cell lines (HepG-2).


2020 ◽  
Vol 17 ◽  
Author(s):  
Ravi Bansal ◽  
Pradeep K. Soni ◽  
Neha Gupta ◽  
Sameer S. Bhagyawant ◽  
Anand K. Halve

Aims: In this article we have developed an eco-friendly one-pot multi-component reaction methodology was employed for the green synthesis of functionalized pyrazole derivatives viz cyclo-condensation of aromatic aldehydes, ethyl acetoacetate and phenyl hydrazine and/or hydrazine hydrate in the presence of cetyltrimethylammoniumbromide (CTAB) at 90°C temperature in aqueous medium. Method: In the present protocol we developed a green method for the synthesis of functionalized pyrazole derivatives through one-pot, multi-component cyclo-condensation of aromatic aldehydes, phenyl hydrazine or hydrazine hydrate and ethyl acetoacetate using cetyltrimethylammoniumbromide (CTAB) as a catalyst in water as solvent. Our methodology confers advantages such as short reaction time, atom economy, purification of product without using column chromatographic and hazardous solvent. The reaction is being catalyzed by cetyltrimethylammoniumbromide (CTAB) and thus products are formed under the green reaction conditions. Results: Initially the reaction of benzaldehyde and phenylhydrazine with ethyl acetoacetate was carried out in water at room temperature in the absence of the catalyst; no product was obtained after 24 h (Table 1 entry 1). When the reaction was carried out using L-proline as catalyst in ethanol at 70°C the yield of product was 20. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. We consider that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in future. In conclusion, we have developed successfully a green and efficient one-pot multi-component methodology for the synthesis of substituted pyrazoles using CTAB as a catalyst in water as solvent with excellent yields. Purifications of compounds were achieved without the use of traditional chromatographic procedures. This methodology has advantages of operational simplicity, clean reaction profiles and relatively broad scope which make it more attractive for the diversity oriented synthesis of these heterocyclic libraries. In this methodology we suggest the further alternative possibility for formation of substituted pyrazoles. The compound 7h can be used as an anticancer drug in pharma industry.


1998 ◽  
Vol 63 (3) ◽  
pp. 363-370 ◽  
Author(s):  
Violetta Patroniak-Krzyminiewska ◽  
Wanda Radecka-Paryzek

The template reactions of 2,6-diacetylpyridine with 3,6-dioxaoctane-1,8-diamine in the presence of dysprosium(III), thulium(III) and lutetium(III) chlorides and erbium(III) perchlorate produce the complexes of 15-membered macrocyclic ligand with an N3O2 set of donor atoms as a result of the [1+1] Schiff base cyclocondensation. In contrast, analogous reactions involving the lighter lanthanide ions (lanthanum(III), samarium(III) and europium(III)) yield the acyclic complexes with terminal acetylpyridyl groupings as products of the partial [2+1] condensation. The complexes were characterized by spectral data (IR, UV-VIS, 1H NMR, MS), and thermogravimetric and elemental analyses.


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