Pub Date : 2019-08-14DOI: 10.11648/J.AJHC.20190503.12
A. Moustafa
The design and syntheses of several novel pyrazole derivatives (2, 5, 6 and 7) and pyrazole derivatives (3 and 4) containing thiazole moiety via by ethyl β-(p-chlorophenyl)–α-cyanoacrylate (1) and thiosemicarbazide as starting materials. Pyrazole derivatives (3 and 4) containing thiazole moiety were synthesized via cyclization of pyrazole derivative (2) with bromomethyl arylketones, to give compound 3, followed by acetylation. N- (3- methoxy-2-hydroxybenzal) -3- (p -chlorophenyl)-4- cyano-5-oxopyrazol-1-thiocarboxamide (6) was synthesized via reaction of compound 2 with 3-methoxy-2-hydroxybenzaldehyde. Structures of all compounds were confirmed by elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. The cytotoxic activity of all the synthetic compounds were evaluated against Leukemia HL-60 compared with Doxorubicicn. The cytotoxic activity was checked in vitro for the recently prepared compounds by using the MTT assay. Compounds 4, 6 and 9 were the most active against Leukemia HL-60. The IC50 values of them were less than 5 µM in the range of 1.35-4.78 µM. In addition, compounds 3 and 5 showed less antiproliferative activity against Leukemia HL-60 cells with IC50 values in the range 5.39-8.82 µM. Compound 6 was the most potent cytotoxic activity. The studies biological activity includes cell cycle analysis, apoptosis detection assay and Topoisomerase II inhibition activity assay explained that compound 6 is a strong Topo II inhibitor.
{"title":"In vitro Anti Leukemia Cancer Activity of Some Novel Pyrazole Derivatives and Pyrazoles Containing Thiazole Moiety","authors":"A. Moustafa","doi":"10.11648/J.AJHC.20190503.12","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190503.12","url":null,"abstract":"The design and syntheses of several novel pyrazole derivatives (2, 5, 6 and 7) and pyrazole derivatives (3 and 4) containing thiazole moiety via by ethyl β-(p-chlorophenyl)–α-cyanoacrylate (1) and thiosemicarbazide as starting materials. Pyrazole derivatives (3 and 4) containing thiazole moiety were synthesized via cyclization of pyrazole derivative (2) with bromomethyl arylketones, to give compound 3, followed by acetylation. N- (3- methoxy-2-hydroxybenzal) -3- (p -chlorophenyl)-4- cyano-5-oxopyrazol-1-thiocarboxamide (6) was synthesized via reaction of compound 2 with 3-methoxy-2-hydroxybenzaldehyde. Structures of all compounds were confirmed by elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. The cytotoxic activity of all the synthetic compounds were evaluated against Leukemia HL-60 compared with Doxorubicicn. The cytotoxic activity was checked in vitro for the recently prepared compounds by using the MTT assay. Compounds 4, 6 and 9 were the most active against Leukemia HL-60. The IC50 values of them were less than 5 µM in the range of 1.35-4.78 µM. In addition, compounds 3 and 5 showed less antiproliferative activity against Leukemia HL-60 cells with IC50 values in the range 5.39-8.82 µM. Compound 6 was the most potent cytotoxic activity. The studies biological activity includes cell cycle analysis, apoptosis detection assay and Topoisomerase II inhibition activity assay explained that compound 6 is a strong Topo II inhibitor.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87982546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-31DOI: 10.11648/J.AJHC.20190503.11
W. E. Smith, D. V. Franklin, Kourtni Lynn Goutierrez, F. Fronczek, F. Mautner, Thomas Junk
Synthetic methods have been developed to prepare novel 1,3-benzotellurazoles carrying acylamino and arylamino moieties in position 2, in order to investigate their propensity to self-assemble to supramolecular structures. The targeted compounds were obtained in yields ranging from 44% to 67%, by reacting bis(2-aminophenyl) ditelluride with acyl- and aryl isothiocyanates, respectively, and subsequent reductive cyclization of the resulting thiourea derivatives. Seven novel 1,3-benzotellurazole derivatives were prepared: 2-benzoylamino-1,3-benzotellurazole, 2-(4-chlorobenzoylamino)-1,3-benzotellurazole, 2-(2-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-methoxybenzoylamino)-1,3-benzotellurazole, 2-phenylamino-1,3-benzotellurazole, and 2-(4-chlorophenylamino-1,3-benzotellurazole. A simplified protocol was employed to synthesize all acyl isothiocyanates needed for their preparation from benzoyl halide derivatives and potassium thiocyanate. The reductive cyclization of the intermediate thioureas was challenging, only the use of hydroxymethanesulfinate in the presence of elemental mercury provided synthetically useful product yields. A mechanism was proposed, consisting of the insertion of mercury into the Te-Te bond, followed by intramolecular nucleophilic attack of the thiocarbonyl moiety by the resulting insertion product. All 2-acylamino-1,3-benzotellurazoles are crystalline solids, which are stable to ambient light, air and moderate heat. A characterization of selected samples by X-ray crystallography indicated that they form dimers in solid state, resulting from hydrogen bonding between the exocyclic and endocyclic nitrogen atoms of two adjacent molecules. This sets them apart from 2-alkyl- and 2-aryl-1,3-benzotellurazoles, which are known to self-assemble into supramolecular wires.
{"title":"Organotellurium Chemistry: Synthesis and Properties of 2-Acylamino- and 2-Arylamino-1,3-benzotellurazoles","authors":"W. E. Smith, D. V. Franklin, Kourtni Lynn Goutierrez, F. Fronczek, F. Mautner, Thomas Junk","doi":"10.11648/J.AJHC.20190503.11","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190503.11","url":null,"abstract":"Synthetic methods have been developed to prepare novel 1,3-benzotellurazoles carrying acylamino and arylamino moieties in position 2, in order to investigate their propensity to self-assemble to supramolecular structures. The targeted compounds were obtained in yields ranging from 44% to 67%, by reacting bis(2-aminophenyl) ditelluride with acyl- and aryl isothiocyanates, respectively, and subsequent reductive cyclization of the resulting thiourea derivatives. Seven novel 1,3-benzotellurazole derivatives were prepared: 2-benzoylamino-1,3-benzotellurazole, 2-(4-chlorobenzoylamino)-1,3-benzotellurazole, 2-(2-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-bromobenzoylamino)-1,3-benzotellurazole, 2-(4-methoxybenzoylamino)-1,3-benzotellurazole, 2-phenylamino-1,3-benzotellurazole, and 2-(4-chlorophenylamino-1,3-benzotellurazole. A simplified protocol was employed to synthesize all acyl isothiocyanates needed for their preparation from benzoyl halide derivatives and potassium thiocyanate. The reductive cyclization of the intermediate thioureas was challenging, only the use of hydroxymethanesulfinate in the presence of elemental mercury provided synthetically useful product yields. A mechanism was proposed, consisting of the insertion of mercury into the Te-Te bond, followed by intramolecular nucleophilic attack of the thiocarbonyl moiety by the resulting insertion product. All 2-acylamino-1,3-benzotellurazoles are crystalline solids, which are stable to ambient light, air and moderate heat. A characterization of selected samples by X-ray crystallography indicated that they form dimers in solid state, resulting from hydrogen bonding between the exocyclic and endocyclic nitrogen atoms of two adjacent molecules. This sets them apart from 2-alkyl- and 2-aryl-1,3-benzotellurazoles, which are known to self-assemble into supramolecular wires.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80024663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-24DOI: 10.11648/J.AJHC.20190502.13
A. Abou, Abdoulaye Djandé, Bintou Sessouma, Rita Kakou Yao, O. Ouari, A. Saba
The title compound, (I), has been solved by direct methods and refined to a final R value of 0.038 for 1835 independent reflections. In the structure, the planar [r.m.s deviation = 0.014 A] chromen-2-one ring and the 7-propionate side chain are inclined to one another at an acute angle of 65.34(9)°. The molecules form R44 (30) tetrameric units via C—H···O interactions which extend into layers approximately parallel to the ab plane. Furthermore, the crystal structure is supported by π–π stacking interactions between neighbouring benzene and pyrone or coumarin rings [centroid–centroid distances in the range 3.6097(8)–3.6475(9)A], as well as C–H···π interactions [H···centroid distances in the range 2.95–3.00A]. The molecular geometry of (I) was also optimized using density functional theory (DFT/RB3LYP), RMP2 and RHF methods with the 6-311++G(d, p) basis set in ground state. The theoretical data resulting from these quantum chemical calculations are in good agreement with the observed structure, although the observed C—O—C—C torsion angle between the coumarin ring system and the 7-propionate side chain (121.49 (16)°) is somewhat lower than the DFT/RB3LYP calculated value (132.32°) and larger than the RMP2 (114.65°) and the RHF (69.19°) values. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.
{"title":"Synthesis, Spectrometric Characterization, X-Ray Crystallography and Quantum Chemical Calculations of 2-oxo-2H-chromen-7-yl Propionate","authors":"A. Abou, Abdoulaye Djandé, Bintou Sessouma, Rita Kakou Yao, O. Ouari, A. Saba","doi":"10.11648/J.AJHC.20190502.13","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190502.13","url":null,"abstract":"The title compound, (I), has been solved by direct methods and refined to a final R value of 0.038 for 1835 independent reflections. In the structure, the planar [r.m.s deviation = 0.014 A] chromen-2-one ring and the 7-propionate side chain are inclined to one another at an acute angle of 65.34(9)°. The molecules form R44 (30) tetrameric units via C—H···O interactions which extend into layers approximately parallel to the ab plane. Furthermore, the crystal structure is supported by π–π stacking interactions between neighbouring benzene and pyrone or coumarin rings [centroid–centroid distances in the range 3.6097(8)–3.6475(9)A], as well as C–H···π interactions [H···centroid distances in the range 2.95–3.00A]. The molecular geometry of (I) was also optimized using density functional theory (DFT/RB3LYP), RMP2 and RHF methods with the 6-311++G(d, p) basis set in ground state. The theoretical data resulting from these quantum chemical calculations are in good agreement with the observed structure, although the observed C—O—C—C torsion angle between the coumarin ring system and the 7-propionate side chain (121.49 (16)°) is somewhat lower than the DFT/RB3LYP calculated value (132.32°) and larger than the RMP2 (114.65°) and the RHF (69.19°) values. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"24 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91501762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.11648/J.AJHC.20190502.12
S. Uddin, Md Saddam Hossain, Md. Abdul Latif, Md. Rabiul Karim, R. Mohapatra, M. Kudrat-E-Zahan
Antibiotic resistance has been growing at an anxious rate and as a result the activity of antibiotics against Gram-negative and Gram-positive bacteria has dropped dramatically day by day. Metal ions play many critical functions in humans. Deficiency of some metal ions can lead to disease like pernicious anemia, growth retardation, heart disease in infants etc. In this sense there is a strong need to synthesis new substances that not only have good spectrum of activity, but having new mechanisms of action. Inorganic compounds particularly Mn metal complexes have played an important role in the development of new metal based drugs. Over the past few years, there have been many reports on their applications in homogeneous and heterogeneous catalysis. The activity is usually increased by complexation therefore to understand the properties of both ligands and metal can lead to the synthesis of highly active compounds. The influence of certain metals on the biological activity of these compounds and their intrinsic chemical interest as multidentate ligands has prompted a considerable increase in the study of their coordination behavior. Development of a new chemotherapeutic Schiff bases and their metal complexes is now attracting the attention of medicinal chemists. In this review we have focused on research of Mn complexes incorporation of Schiff bases carry out over the past few decades which has sought to possess preclinical pharmacological screenings like anti-bacterial, anti-fungal, anti-tuberculosis, anti-inflammatory, anti-cancer, DNA- interaction and anti-tumor action of synthetic metal complexes.
{"title":"Antimicrobial Activity of Mn Complexes Incorporating Schiff Bases: A Short Review","authors":"S. Uddin, Md Saddam Hossain, Md. Abdul Latif, Md. Rabiul Karim, R. Mohapatra, M. Kudrat-E-Zahan","doi":"10.11648/J.AJHC.20190502.12","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190502.12","url":null,"abstract":"Antibiotic resistance has been growing at an anxious rate and as a result the activity of antibiotics against Gram-negative and Gram-positive bacteria has dropped dramatically day by day. Metal ions play many critical functions in humans. Deficiency of some metal ions can lead to disease like pernicious anemia, growth retardation, heart disease in infants etc. In this sense there is a strong need to synthesis new substances that not only have good spectrum of activity, but having new mechanisms of action. Inorganic compounds particularly Mn metal complexes have played an important role in the development of new metal based drugs. Over the past few years, there have been many reports on their applications in homogeneous and heterogeneous catalysis. The activity is usually increased by complexation therefore to understand the properties of both ligands and metal can lead to the synthesis of highly active compounds. The influence of certain metals on the biological activity of these compounds and their intrinsic chemical interest as multidentate ligands has prompted a considerable increase in the study of their coordination behavior. Development of a new chemotherapeutic Schiff bases and their metal complexes is now attracting the attention of medicinal chemists. In this review we have focused on research of Mn complexes incorporation of Schiff bases carry out over the past few decades which has sought to possess preclinical pharmacological screenings like anti-bacterial, anti-fungal, anti-tuberculosis, anti-inflammatory, anti-cancer, DNA- interaction and anti-tumor action of synthetic metal complexes.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90598123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.11648/J.AJHC.20190501.12
Gunanka Hazarika, P. K. Tripathy
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.
{"title":"Solvent Free Quick Conversion of Mono - And Dicarboxylic Acids into Their Corresponding Anilides with Phenylisothiocyanate","authors":"Gunanka Hazarika, P. K. Tripathy","doi":"10.11648/J.AJHC.20190501.12","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190501.12","url":null,"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.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84186264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.11648/J.AJHC.20190501.11
P. Bhuyan, P. K. Tripathy
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.
{"title":"Study on the Condensation of Different Hydroxy Aromatic Aldehydes with 2-Substituted 2-Oxazolin-5-ones Generated in situ","authors":"P. Bhuyan, P. K. Tripathy","doi":"10.11648/J.AJHC.20190501.11","DOIUrl":"https://doi.org/10.11648/J.AJHC.20190501.11","url":null,"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.","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77278030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11648/j.ajhc.20190501.14
Md. Nur Amin Bitu
{"title":"Anti-pathogenic Activity of Cu(II) Complexes Incorporating Schiff Bases: A Short Review","authors":"Md. Nur Amin Bitu","doi":"10.11648/j.ajhc.20190501.14","DOIUrl":"https://doi.org/10.11648/j.ajhc.20190501.14","url":null,"abstract":"","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82498834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-01-01DOI: 10.11648/j.ajhc.20190502.11
Sirsat Shivraj Balajirao
{"title":"Synthesis of Novel Pyrimido Thiazine and Their Derivatives","authors":"Sirsat Shivraj Balajirao","doi":"10.11648/j.ajhc.20190502.11","DOIUrl":"https://doi.org/10.11648/j.ajhc.20190502.11","url":null,"abstract":"","PeriodicalId":7715,"journal":{"name":"American Journal of Heterocyclic Chemistry","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86580758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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