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Study on the Condensation of Different Hydroxy Aromatic Aldehydes with 2-Substituted 2-Oxazolin-5-ones Generated in situ
Pubanita Bhuyan,
Pradeep K. Tripathy
Issue:
Volume 5, Issue 1, March 2019
Pages:
1-3
Received:
25 January 2019
Accepted:
14 March 2019
Published:
8 April 2019
Abstract: In view to synthesize some bioactive 2-Substituted 4-(hydroxybenzylidene)-2-oxazolin-5-ones through a disciplined route, a study on the condensation of 2-, 3- and 4- hydroxy aromatic aldehydes (6) with 2-Substituted 2-oxazolin-5-ones (5) was carried out. 2-Substituted 2-oxazolin-5-ones (5) which are also known as saturated azlactones and unstable, were generated in situ from α-N-Acylglycines (1) using various cyclising agents namely ethyl chloroformate (2), benzene sulphonyl chloride (3) and p-toluene sulphonyl chloride (4) in dry benzene in presence of triethylamine base. The hydroxyl group at 3- and 4- positions of aromatic aldehydes namely 4-hydroxy-3-methoxybenzaldehyde (6a), m-hydroxybenzaldehyde (6b)and p-hydroxybenzaldehyde (6c) produce 2-substituted 4-(p-hydroxy-m-methoxybenzylidene)-2-oxazolin-5-one (8a), 2-substituted-4 (m-hydroxybenzylidene)-2-oxazolin-5-one (8b) and2-substituted-4 (p-hydroxybenzylidene)-2-oxazolin-5-one (8c) respectively as their (Z)-isomers, whereas 2-hydroxy aromatic aldehyde namely salicylaldehydeproduces 3-N-acylaminocoumarins (9) on condensation with 2-Substituted 2-oxazolin-5-ones (5) in appreciable yields and good purity. The reaction seems to be initiated by the formation of an adduct (E)-2-substituted 4-(o-hydroxybenzylidene-2-oxazolin-5-ones (7), followed by intramolecular 1,5- bond cleavage of the 2-oxazolin-5-one ring by the vicinal phenolic group and subsequent recyclization led to the formation of resultant 3-N-acylaminocoumarins (9). It is noteworthy that free hydroxyl group bearing benzylidene moiety at 4-position of 2-oxazolin-5-ones (8) were obtained. All the steps can be carried out in one flask.
Abstract: In view to synthesize some bioactive 2-Substituted 4-(hydroxybenzylidene)-2-oxazolin-5-ones through a disciplined route, a study on the condensation of 2-, 3- and 4- hydroxy aromatic aldehydes (6) with 2-Substituted 2-oxazolin-5-ones (5) was carried out. 2-Substituted 2-oxazolin-5-ones (5) which are also known as saturated azlactones and unstable, ...
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Solvent Free Quick Conversion of Mono - And Dicarboxylic Acids into Their Corresponding Anilides with Phenylisothiocyanate
Gunanka Hazarika,
Pradeep K. Tripathy
Issue:
Volume 5, Issue 1, March 2019
Pages:
4-6
Received:
25 January 2019
Accepted:
15 March 2019
Published:
8 April 2019
Abstract: The attraction of isothiocyanates as synthons and as cyclizing agents continues due to their diverse reactions and also due to their easy availability. It would not be out of place to mention that, in comparison to isocyanates (-N=C=O), their Sulphur analogues, isothiocyanates (-N=C=S), are less unpleasant and to some extent less hazardous. The use of isocyanates is drastically limited by the researchers [6] after December 3, 1984 which is the date of Bhopal Disaster held in Union carbide factory, Bhopal, Madhya Pradesh (India) due to the leakage of Methyl isocyanate (MIC) where thousands of people were died due to the toxic effect of MIC (Me-N=C=O). In the present study, a mixture of Phenyl isothiocyanate (2) and monocarboxylic acid (1), in the ratio of 1:1 and Phenyl isothiocyanate (2) and dicarboxylic acid (4) in the ratio of 2:1are taken for condensation reaction by heating at 160°-170°C for 15 minutesunder solvent free condition. Pyridine was used as a catalyst/ base in both the cases. The products obtained were monoanilides (3) and dianilides (5) of mono- and dicarboxylic acids respectively which were recrystallized from aqueous ethanol. Dicarboxylic acids gave unexpected results in some of the cases. For example, Phthalic acid produces N-phenylphthalimide irrespective of the molar ratio of the acid and Phenyl isothiocyanate whereas maleic acid produces neither mono- nor dianilides with Phenyl isothiocyanate under the present condition. A proper systematic investigation was carried out towards the condensation of Phenyl isothiocyanate with mono- and dicarboxylic acids.
Abstract: The attraction of isothiocyanates as synthons and as cyclizing agents continues due to their diverse reactions and also due to their easy availability. It would not be out of place to mention that, in comparison to isocyanates (-N=C=O), their Sulphur analogues, isothiocyanates (-N=C=S), are less unpleasant and to some extent less hazardous. The use...
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Antibacterial Effects and Synthesized New Derivatives of 4-Hydroxy-Chromen-2-One
Aziz Behrami,
Florent Dobroshi
Issue:
Volume 5, Issue 1, March 2019
Pages:
7-10
Received:
28 January 2019
Accepted:
21 March 2019
Published:
15 April 2019
Abstract: In present paper, we report the organic syntheses of three compounds exactly 4-hydroxy-chromen-2-one and describe the results of antibacterial activity of purified compounds. Compounds 4-(4-Methoxy-phenylamino)-2-oxo-2H-chromene-3-sulfonyl chloride (a). N-{3-[Diethoxy-(2-hydroxy-phenyl)-methyl]-2-oxo-2H-chromen-4-yl}-acetamide (b), 4-(6-Nitro-benzothiazol-2-ylamino)-2-oxo-2H-chromene-3-carbaldehyde (c), have been synthesized and characterized using melting points, IR spectra, 1H-NMR and 13C-NMR spectra. Our research goal is synthesis novel organic compounds which prove high level of antibacterial activity. The antibacterial activity of synthesized compounds and streptomycin and cefalexine at concentrations of 2mg/ml, 3mg/ml and 5mg/ml, have been evaluated against three strains of bacterial culture; Staphylococcus aureus, E. coli and Bacillus cereus. The compounds show bacteriostatic and bactericidal activity in high level and also synthetized compounds has been characterized using advanced instrumental methods of analysis.
Abstract: In present paper, we report the organic syntheses of three compounds exactly 4-hydroxy-chromen-2-one and describe the results of antibacterial activity of purified compounds. Compounds 4-(4-Methoxy-phenylamino)-2-oxo-2H-chromene-3-sulfonyl chloride (a). N-{3-[Diethoxy-(2-hydroxy-phenyl)-methyl]-2-oxo-2H-chromen-4-yl}-acetamide (b), 4-(6-Nitro-benzo...
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Anti-pathogenic Activity of Cu(II) Complexes Incorporating Schiff Bases: A Short Review
Md. Nur Amin Bitu,
Md. Saddam Hossain,
A. A. S. M. Zahid,
C. M. Zakaria,
Md. Kudrat-E-Zahan
Issue:
Volume 5, Issue 1, March 2019
Pages:
11-22
Received:
20 February 2019
Accepted:
25 March 2019
Published:
22 April 2019
Abstract: Metals contribute important roles in biological system. It is recognized that metals are highly linked in cellular and subcellular functions. With the application of novel and experienced tools to study biological and biochemical systems the true role of inorganic salts in biological systems can be studied. Schiff base metal complexes show a broad range of biological activity. The activity of Schiff base ligand is usually increased by complexation with the metal ion. The copper complexes of Schiff bases have striking properties such as antibacterial, antifungal, antiviral, anti-inflammatory, anti-tumor and cytotoxic activities, plant development controller, enzymatic activity and applications in pharmaceutical fields. The divalent cations Zn2+, Ca2+ and Mg2+ prevent cytotoxicity and in vivo antagonize Cd- induced carcinogenesis. Lack of body iron is common in cancer patients and it is associated with complications in surgery and in animal experiments. The transport of iron and other metal ions by the blood plasma is achieved through the formation of protein complexes. Copper is placed as a vital metalloelement and is primarily connected with copper-dependent cellular enzymes. Metals are also used as inorganic drugs for many diseases. In this review our main focused on research undertaken for biological activity study of Cu(II) metal complexes containing Schiff bases over the past few decades.
Abstract: Metals contribute important roles in biological system. It is recognized that metals are highly linked in cellular and subcellular functions. With the application of novel and experienced tools to study biological and biochemical systems the true role of inorganic salts in biological systems can be studied. Schiff base metal complexes show a broad ...
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