Reaction of imines with 2-silyloxydiene catalyzed by ammonium chloride has been perfectly proceeded under environmentally friendly conditions to give Mannich-type product selectively. The reaction would proceed via Mannich-type mechanism, not cyclization/ring-opening process. Cyclopropanation of the corresponding Mannich-type product gave the precursor of prasugrel skeleton in high yield.
{"title":"Mannich-Type Reaction of Aldimines with 2-Silyloxydienes Catalyzed by Ammonium Chloride","authors":"Shoichi Fukumoto, Miho Shigenobu, K. Ishimaru","doi":"10.4236/ijoc.2019.94014","DOIUrl":"https://doi.org/10.4236/ijoc.2019.94014","url":null,"abstract":"Reaction of imines with 2-silyloxydiene catalyzed by ammonium chloride has been perfectly proceeded under environmentally friendly conditions to give Mannich-type product selectively. The reaction would proceed via Mannich-type mechanism, not cyclization/ring-opening process. Cyclopropanation of the corresponding Mannich-type product gave the precursor of prasugrel skeleton in high yield.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42760536","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}
Olusegun B. Olubanwo, Arianna H. Kazez, D. Carney, J. Sello
A new class of potential antibacterial agents has been synthesized on a new molecular scaffold of cyclohexane carboxylate. We have tagged this new class of compounds TACCs (Trisubstituted Aryl Cyclohexanecarboxylate). These new molecules are structural analogues of an Activators of Self-Compartmentalizing Proteases 4 and 5 (ACP 4 and 5), and were synthesized to circumvent the drug-like property (drug-ability) challenges and liability noted in ACP 4 and 5. A pseudo-Robinson annulation protocol was used to furnish this new class of potential antibiotics. Structure-activity relationship (SAR) study was done to identify the pharmacophore(s) in this molecular scaffold. A selection of these compounds was used in our preliminary antibacterial inhibitory activities’ studies on Bacillus mycoides and Bacillus subtilis. These preliminary studies show that the TACCs exhibited equal, and in some cases better, antibacterial activity than ACP 4 and 5.
{"title":"Trisubstituted Aryl Cyclohexanecarboxylates (TACC): A Simple, New Molecular Scaffold for Antibiotics Design","authors":"Olusegun B. Olubanwo, Arianna H. Kazez, D. Carney, J. Sello","doi":"10.4236/ijoc.2019.93013","DOIUrl":"https://doi.org/10.4236/ijoc.2019.93013","url":null,"abstract":"A new class of potential antibacterial agents has been synthesized on a new molecular scaffold of cyclohexane carboxylate. We have tagged this new class of compounds TACCs (Trisubstituted Aryl Cyclohexanecarboxylate). These new molecules are structural analogues of an Activators of Self-Compartmentalizing Proteases 4 and 5 (ACP 4 and 5), and were synthesized to circumvent the drug-like property (drug-ability) challenges and liability noted in ACP 4 and 5. A pseudo-Robinson annulation protocol was used to furnish this new class of potential antibiotics. Structure-activity relationship (SAR) study was done to identify the pharmacophore(s) in this molecular scaffold. A selection of these compounds was used in our preliminary antibacterial inhibitory activities’ studies on Bacillus mycoides and Bacillus subtilis. These preliminary studies show that the TACCs exhibited equal, and in some cases better, antibacterial activity than ACP 4 and 5.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43141068","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}
Xanthene and Xanthenediones are structural components of several bioactive and semi-synthetic molecules. This work described an expeditious synthesis of novel and hitherto unreported bis-trifluoromethyl xanthene dione derivatives. The reaction of two equivalents of 5-trifluoromethyl cyclohexane-1,3- dione with substituted aromatic aldehydes in the presence of ethanol containing 1 - 2 drops of HCl was facile under microwave irradiation. Short reaction time (25 min), good to excellent yields (80% - 95%), good atom economy, and simple workup are the major advantages of the above procedure. Moreover, the fluorinated products represent synthetically useful stable intermediates that could find applications in pharmaceutical, agricultural and material industries.
{"title":"Facile Synthesis of Bis-Trifluoromethyl 1,8-Dioxo-Octahydroxanthene Derivatives","authors":"Cosmas O. Okoro, M. A. Ogunwale, A. Oyedele","doi":"10.4236/IJOC.2019.93011","DOIUrl":"https://doi.org/10.4236/IJOC.2019.93011","url":null,"abstract":"Xanthene and Xanthenediones are structural components of several bioactive and semi-synthetic molecules. This work described an expeditious synthesis of novel and hitherto unreported bis-trifluoromethyl xanthene dione derivatives. The reaction of two equivalents of 5-trifluoromethyl cyclohexane-1,3- dione with substituted aromatic aldehydes in the presence of ethanol containing 1 - 2 drops of HCl was facile under microwave irradiation. Short reaction time (25 min), good to excellent yields (80% - 95%), good atom economy, and simple workup are the major advantages of the above procedure. Moreover, the fluorinated products represent synthetically useful stable intermediates that could find applications in pharmaceutical, agricultural and material industries.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43661372","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}
Oil and gas operations depend heavily on water in many different aspects. Water is present wherever there is hydrocarbon production. It is produced along with the hydrocarbons and helps in mobilizing them. It is also injected into the reservoirs to aid in mobilizing the hydrocarbons, maintain the pressure and increase the recovery of the development project. With water presence, some serious problems occur such as scaling. Scaling is a well-known problematic precipitation caused mainly due to mixing of two incompatible fluids, changes in temperature and pressure conditions and disturbance to thermodynamics and kinetics of reservoir fluids. They can be found at any point of the operations starting down at the formation up to the surface tanks. Scales are directly responsible for compromising the economics and safety of development projects. This review paper is going to include a recap of the importance of water in the oil and gas industry, then review the different types of scales as well as their properties including carbonate and sulfate scales. After that, famous scales from each type is going to be reviewed as well as their properties and precipitation conditions such as Calcium Carbonate CaCO3, Calcium Sulfate CaSO4, Barium Sulfate BaSO4 and Strontium Sulfate SrSO4. Moreover, common practices and precautions steps in the industry are going to be reviewed as well. Finally, the paper presents the common practices used by the operators for scale removal.
{"title":"Water Chemistry in Oil and Gas Operations: Scales Properties and Composition","authors":"A. Taha, M. Amani","doi":"10.4236/ijoc.2019.93012","DOIUrl":"https://doi.org/10.4236/ijoc.2019.93012","url":null,"abstract":"Oil and gas operations depend heavily on water in many different aspects. Water is present wherever there is hydrocarbon production. It is produced along with the hydrocarbons and helps in mobilizing them. It is also injected into the reservoirs to aid in mobilizing the hydrocarbons, maintain the pressure and increase the recovery of the development project. With water presence, some serious problems occur such as scaling. Scaling is a well-known problematic precipitation caused mainly due to mixing of two incompatible fluids, changes in temperature and pressure conditions and disturbance to thermodynamics and kinetics of reservoir fluids. They can be found at any point of the operations starting down at the formation up to the surface tanks. Scales are directly responsible for compromising the economics and safety of development projects. This review paper is going to include a recap of the importance of water in the oil and gas industry, then review the different types of scales as well as their properties including carbonate and sulfate scales. After that, famous scales from each type is going to be reviewed as well as their properties and precipitation conditions such as Calcium Carbonate CaCO3, Calcium Sulfate CaSO4, Barium Sulfate BaSO4 and Strontium Sulfate SrSO4. Moreover, common practices and precautions steps in the industry are going to be reviewed as well. Finally, the paper presents the common practices used by the operators for scale removal.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47806463","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}
L. M. Break, M. A. Mohamed, Ohoud A. A. Al-Thubaiti, Fatma E. M. Eibaih
Pyrimidines, such as 6-amino-2-thio and 2-methylthiouracils and fused pyrimidines, such as thienopyrimidines reacted with 1-O-acetyl-2,3,5-tri-O- benzoyl-β-D-ribofuranose to get new derivatives of the corresponding nucleosides. The obtained protected nucleosides were deprotected by methanolic sodium methoxide to get the corresponding free uracil and thienopyrimidine nucleosides. The new nucleosides formed were tested for biological activity against some of microorganism (some fungi and bacteria species). Some of the tested products showed moderate activity and the results were reported.
{"title":"Nucleosides 10: Synthesis of New Derivatives of Pyrimidine and Fused Pyrimidine Nucleosides of Expected Biological Activity","authors":"L. M. Break, M. A. Mohamed, Ohoud A. A. Al-Thubaiti, Fatma E. M. Eibaih","doi":"10.4236/IJOC.2019.93010","DOIUrl":"https://doi.org/10.4236/IJOC.2019.93010","url":null,"abstract":"Pyrimidines, such as 6-amino-2-thio and 2-methylthiouracils and fused pyrimidines, such as thienopyrimidines reacted with 1-O-acetyl-2,3,5-tri-O- benzoyl-β-D-ribofuranose to get new derivatives of the corresponding nucleosides. The obtained protected nucleosides were deprotected by methanolic sodium methoxide to get the corresponding free uracil and thienopyrimidine nucleosides. The new nucleosides formed were tested for biological activity against some of microorganism (some fungi and bacteria species). Some of the tested products showed moderate activity and the results were reported.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49103900","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}
The construction of the C(1) - C(5) fragment of the resorcylic acid lactone pochonin J is described. The synthesis is marked by the installation of the cis-1,3-diol moiety in a highly stereoselective manner using Evans’ intra-molecular base-catalyzed oxyconjugate addition of a hemiacetal-derived nucleophile. The synthetic route presented affords an efficient pathway to the preparation of this critical architectural feature that should facilitate the development of this secondary metabolite as a potential drug candidate.
{"title":"Progress toward the Synthesis of Pochonin J","authors":"Sydney N Jackson, R. Pongdee","doi":"10.4236/IJOC.2019.92009","DOIUrl":"https://doi.org/10.4236/IJOC.2019.92009","url":null,"abstract":"The construction of the C(1) - C(5) fragment of the resorcylic acid lactone pochonin J is described. The synthesis is marked by the installation of the cis-1,3-diol moiety in a highly stereoselective manner using Evans’ intra-molecular base-catalyzed oxyconjugate addition of a hemiacetal-derived nucleophile. The synthetic route presented affords an efficient pathway to the preparation of this critical architectural feature that should facilitate the development of this secondary metabolite as a potential drug candidate.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42839192","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}
R. -Rahman, Abdulrahman S. Alharbi, N. A. Alshammari
Novel 4-thiazolidione and 1,4-bis-thiazolidinone derivatives bearing antipyrine moiety have been obtained from condensation of 4-aminoantipyrine 1 with aromatic/heteroaldehydes followed by cycloaddition with mercaptoacetic acid in nonpolar solvents. Structure of the products has been deduced upon their elemental analysis and spectral measurements. Most of the targets evaluated as enzymatic effect towards some bacteria (E. coli) in compare with Xanthine oxidase (from buttermilk) where the role of compounds is an inhibition of purine metabolism enzymes caused by E. coli.
{"title":"Synthesis of Novel 4-Thiazolidinone and Bis-Thiazalidin-4-One Derivatives Derived from 4-Amino-Antipyrine and Evaluated as Inhibition of Purine Metabolism Enzymes by Bacteria","authors":"R. -Rahman, Abdulrahman S. Alharbi, N. A. Alshammari","doi":"10.4236/IJOC.2019.92008","DOIUrl":"https://doi.org/10.4236/IJOC.2019.92008","url":null,"abstract":"Novel 4-thiazolidione and 1,4-bis-thiazolidinone derivatives bearing antipyrine moiety have been obtained from condensation of 4-aminoantipyrine 1 with aromatic/heteroaldehydes followed by cycloaddition with mercaptoacetic acid in nonpolar solvents. Structure of the products has been deduced upon their elemental analysis and spectral measurements. Most of the targets evaluated as enzymatic effect towards some bacteria (E. coli) in compare with Xanthine oxidase (from buttermilk) where the role of compounds is an inhibition of purine metabolism enzymes caused by E. coli.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48998369","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}
The direct aroylation of ArCOPdCl with potassium aryltrifluoroborates establishes a new cross-coupling synthetic tool for the synthesis of various fluorine substituted benzophenones. The new microwave irradiated process is very efficient and produce high yield benzophenone products within minutes.
{"title":"Efficient Cross-Coupling Reaction of Aryltrifluoroborates and Aroyl Chlorides for the Synthesis of Fluorine Substituted Aromatic Ketones","authors":"Mohammed Al-Masum, Tasfia Islam, Grady Clopton","doi":"10.4236/IJOC.2019.91006","DOIUrl":"https://doi.org/10.4236/IJOC.2019.91006","url":null,"abstract":"The direct aroylation of ArCOPdCl with potassium aryltrifluoroborates establishes a new cross-coupling synthetic tool for the synthesis of various fluorine substituted benzophenones. The new microwave irradiated process is very efficient and produce high yield benzophenone products within minutes.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44911101","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}
Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.
{"title":"Synthesis of Novel Heteropolycyclic Nitrogen Systems Bearing Fluorine Substituted Pyrazolo[3,4-d] Pyrimidine Derived from Polyfunctional π-Acceptor Compounds and Guanidine as Fungicidal Probes","authors":"D. Bakhotmah, Salwa Y. Al-Hazme","doi":"10.4236/IJOC.2019.91007","DOIUrl":"https://doi.org/10.4236/IJOC.2019.91007","url":null,"abstract":"Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43537147","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}
A. G. Bordón, A. N. Pila, Mariela I. Profeta, M. Jorge, L. C. Jorge, J. M. Romero, N. Jorge
The thermal decomposition of Cyclic Diperoxide of Benzaldehyde 3,6-diphenyl-1,2,4,5-tetroxane, (DFT) in chlorobenzene solution in the studied temperature range (130°C - 166°C) satisfactorily satisfies a first order law up to 60% conversions of diperoxide. DFT would decompose through a mechanism in stages and initiated by the homolytic breakdown of one of the peroxidic bonds of the molecule, with the formation of the corresponding intermediate biradical. The concentration studied was very low, so that the effects of secondary reactions of decomposition induced by free radicals originated in the reaction medium can be considered minimal or negligible. The activation parameters for the unimolecular thermal decomposition reaction of the DFT are ΔH# = 30.52 ± 0.3 kcal·mol-1 and ΔS# = -6.38 ± 0.6 cal·mol-1 K-1. The support for a step-by-step mechanism instead of a process concerted is made by comparison with the theoretically calculated activation energy for the thermal decomposition of 1,2,4,5-tetroxane.
{"title":"Thermal Decomposition of Diphenyl Tetroxane in Chlorobenzene Solution","authors":"A. G. Bordón, A. N. Pila, Mariela I. Profeta, M. Jorge, L. C. Jorge, J. M. Romero, N. Jorge","doi":"10.4236/ijoc.2019.91001","DOIUrl":"https://doi.org/10.4236/ijoc.2019.91001","url":null,"abstract":"The thermal decomposition of Cyclic Diperoxide of Benzaldehyde 3,6-diphenyl-1,2,4,5-tetroxane, (DFT) in chlorobenzene solution in the studied temperature range (130°C - 166°C) satisfactorily satisfies a first order law up to 60% conversions of diperoxide. DFT would decompose through a mechanism in stages and initiated by the homolytic breakdown of one of the peroxidic bonds of the molecule, with the formation of the corresponding intermediate biradical. The concentration studied was very low, so that the effects of secondary reactions of decomposition induced by free radicals originated in the reaction medium can be considered minimal or negligible. The activation parameters for the unimolecular thermal decomposition reaction of the DFT are ΔH# = 30.52 ± 0.3 kcal·mol-1 and ΔS# = -6.38 ± 0.6 cal·mol-1 K-1. The support for a step-by-step mechanism instead of a process concerted is made by comparison with the theoretically calculated activation energy for the thermal decomposition of 1,2,4,5-tetroxane.","PeriodicalId":64796,"journal":{"name":"有机化学国际期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41430986","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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