Dr. V Siddaiah - Academia.edu (original) (raw)
Papers by Dr. V Siddaiah
Russian Journal of Organic Chemistry, 2020
The first stereoselective total synthesis of the linear pentaketide Modiolin has been performed v... more The first stereoselective total synthesis of the linear pentaketide Modiolin has been performed via Jacobsen’ hydrolytic kinetic resolution and 2C-Wittig homologation as key steps.
International Journal of Engineering and Applied Sciences, 2017
Water is an essential component for the survival of the eco systems and all the living organisms ... more Water is an essential component for the survival of the eco systems and all the living organisms on the earth. Due to agricultural activities, rapid industrialization and growth in urban population, the water sources are being contaminated by anthropogenic activities. Keepingnbsp in view the rapid industrialization in East Godavari region, it is proposed to characterize the effluent water generated from the paper industry and ground water collected from the surrounding areas of the industry to assessnbsp the impact of paper industrial effluentnbsp on ground water quality .The present work is focused on characterization of effluent and ground water collectednbsp physiologicalnbsp parameters viz.,pH, EC,TDS,TH, TA, Chloride, Sulphate, Nitrate,nbsp Phosphate, Na, K,Ca,Mg for assessing the chemical contamination of water. Irrigation parameters like, Percent sodium, SAR, RSC, KR and MH are determined to verify the suitability of water for irrigation purposes. Further thenbsp waters are c...
Asian Journal of Chemistry, 2018
Soil is a general term usually denotes the unconsolidated thin, variable layer of mineral and org... more Soil is a general term usually denotes the unconsolidated thin, variable layer of mineral and organic material usually biologically active which covers rest of the earth land surface. Soil properties are sensitive to various changes in the management and can be employed as indicators. In India, large numbers of fertilizers are employed instead of manures as such the crop productivity increases speedily but the quality of soil support decreases. It is difficult to control the adverse effects of the chemical fertilizers to the soil, plants, animals and human being [1,2]. Analysis of soil was carried out for the studies of various parameters like pH, conductivity, TDS, organic carbon, available nitrate nitrogen, calcium and magnesium. Various devastating ecological and human disasters of the last four decades implicate industries as a major contribution to environmental degradation and pollution [3-5].
![Research paper thumbnail of A Novel Process for the Preparation of [(R,S)/(S,R)] and [(S,S)/(R,R)] Chroman epoxides, Key Intermediates in the Synthesis of Nebivolol](https://attachments.academia-assets.com/111541709/thumbnails/1.jpg)
](International Journal of Bioassays, 2017
A novel, cost effective, scalable process for the preparation of chroman epoxides starting from 4... more A novel, cost effective, scalable process for the preparation of chroman epoxides starting from 4-fluorophenol is described. The highlights of the process are single step O-acylation, fries rearrangement, one pot synthesis of claisen condensation, cyclization, reduction, epoxidation with over all yield of 50.9% [(R,S)/(S,R)]-chroman epoxide-A is 33.9% and [(S,S)/(R,R)]-chroman epoxide-B is 17%.
Grasas y Aceites, 2017
In the present study, the supercritical carbon dioxide (CO2) extraction of oil from Simarouba glu... more In the present study, the supercritical carbon dioxide (CO2) extraction of oil from Simarouba gluaca seeds was carried out at varying conditions of pressure (300–500 bar), temperature (50–70 °C) and CO2 flow rate (10–30 g·min-1). The extraction condition for maximum oil yield was obtained at 500 bar pressure, 70 °C and at 30 g·min-1 flow rate of CO2. The extracted oil was analyzed thoroughly for physico-chemical properties and compared with those of conventional solvent extracted oil. An interesting observation is a significant reduction in the phosphorus content of the oil (8.4 mg·kg-1) extracted using supercritical CO2 compared to the phosphorous content of the solvent extracted oil (97 mg·kg-1). Moreover, the content of total tocopherols in supercritically extracted oil (135.6 mg·kg-1) was found to be higher than the solvent extracted oil (111 mg·kg-1). The rest of the physico-chemical properties of the two differently extracted oils matched well with each other. The results indi...
Synthetic Communications, 2013
ABSTRACT A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-... more ABSTRACT A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-phenyl-5(4H)-oxazolones via reactions of hippuric acid with various aldehydes in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine/N-methylmorpholine at 75 °C.Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.
Green Chemistry Letters and Reviews, 2012
We have reported an efficient and eco-friendly protocol for the protection of various structurall... more We have reported an efficient and eco-friendly protocol for the protection of various structurally and electronically divergent aryl and aliphatic amines using Cbz-Cl in the presence of polyethylene glycol (PEG)-400 at room temperature. The reaction afforded excellent yields with low as well as high molecular weight PEGs.
Chemistry Letters, 2010
... V. Siddaiah,* GM Basha, G. Padma Rao, U. Viplava Prasad, and R. Suryachendra Rao Department o... more ... V. Siddaiah,* GM Basha, G. Padma Rao, U. Viplava Prasad, and R. Suryachendra Rao Department of Organic Chemistry & FDW, Andhra University, Visakhapatnam 530 003, India ... 11 a) RK Pandey, SP Dagade, RK Upadhyay, MK Dongare, P. Kumar, Arkivoc 2002, Part vii, 28. ...
Catalysis Letters, 2011
Page 1. HClO4-SiO2: An Efficient Reusable Catalyst for the Synthesis of 3,4,5-Trisubstituted 1,2,... more Page 1. HClO4-SiO2: An Efficient Reusable Catalyst for the Synthesis of 3,4,5-Trisubstituted 1,2,4-Triazoles Under Solvent-Free Conditions Vidavalur Siddaiah Gajula Mahaboob Basha Rayavarapu Srinuvasarao Santosh Kumar Yadav ...
Canadian Journal of Chemistry, 2013
A mild and efficient one-flask method has been developed for the synthesis of chromones, isoflavo... more A mild and efficient one-flask method has been developed for the synthesis of chromones, isoflavones, and homoisoflavones from 2-hydroxyacetophenones, deoxybenzoins, and dihydrochalcones, respectively, via one-carbon extension using the complex 2,4,6-trichloro-1,3,5-triazine/dimethylformamide. Deoxybenzoins and dihydrochalcones were prepared in situ by the reaction of readily available substituted phenols with phenylacetic acids and 3-phenylpropanoic acids, respectively. This method allows the synthesis of a wide range of compounds with multiple phenolic hydroxyls and other substituents. The methodology has been applied to the synthesis of three naturally occurring isoflavones such as formononetin (9c), daidzein (9d), and retusin (9h).
Asian Journal of Chemistry, 2017
An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is ... more An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is developed via Knoevenagel condensation of aromatic aldehydes with malonic acid and malononitrile in the presence of catalytic amounts of DABCO. This method has many advantages, such as mild reaction conditions, excellent yields, short reaction times and no furthur purification required.
Chemical Data Collections, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Chemical Data Collections, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
![Research paper thumbnail of Synthesis and Antimicrobial Activity of 3-{2-[(1-Aryl-1H-1,2,3-triazol-4-yl)methoxy]-5-fluorophenyl}isoxazoles](https://attachments.academia-assets.com/105978356/thumbnails/1.jpg)
](Russian Journal of General Chemistry, 2019
A novel series 3-{2-[(1-aryl-1H-1,2,3-triazol-4-yl)methoxy]-5-fluorophenyl}isoxazoles derivatives... more A novel series 3-{2-[(1-aryl-1H-1,2,3-triazol-4-yl)methoxy]-5-fluorophenyl}isoxazoles derivatives is synthesized from 1-(5-fluoro-2-hydroxyphenyl)ethanone. All the synthesized compounds are characterized by IR, 1 H and 13 C NMR, and mass spectral data, and tested for their in vitro antimicrobial activity against bacterial and fungal organisms.
Journal of Molecular Catalysis A: Chemical, 2006
Substituted coumarins are synthesized from phenols and ethyl acetoacetate or methyl acetoacetate ... more Substituted coumarins are synthesized from phenols and ethyl acetoacetate or methyl acetoacetate via Pechmann condensation using heterogeneous recyclable catalyst (HClO4· SiO2) under solvent-free conditions. This method is simple, cost effective, requires short ...
![Research paper thumbnail of Reaction of Imidoformates with Anthranilates: Facile, One-Pot, Three-Component Synthesis of 8 H -Quinazolino[4,3-b]quinazolin-8-ones](https://attachments.academia-assets.com/105978358/thumbnails/1.jpg)
](Journal of Heterocyclic Chemistry, 2013
Bioorganic & Medicinal Chemistry Letters, 2007
Bioorganic & Medicinal Chemistry, 2006
A series of four naturally occurring homoisoflavonoids and eight analogs have been synthesized st... more A series of four naturally occurring homoisoflavonoids and eight analogs have been synthesized starting from an appropriately substituted phenol through chroman-4-one, in four steps. The products were assigned as E-isomers based on NMR spectroscopic data. The E-isomers were converted into Z-isomers by photoisomerization. The E-and Z-isomers showed distinct chemical shifts and the differences between (E) and (Z)-homoisoflavonoids in the proton NMR spectra afford a useful method for ascertaining the stereochemistry. The antioxidant activity of homoisoflavonoids was determined by superoxide (NBT) and DPPH free radical scavenging methods. The analog 7-hydroxy-3-[(3,4,5-trihydroxyphenyl)methylene]chroman-4-one displayed excellent activity followed by sappanone A in both the methods and were several times potent than the commercial antioxidants like BHA, BHT, etc. These compounds were evaluated in vitro for their inhibitory activities against 5-lipoxygenase (5-LOX) enzyme. The analog 7-hydroxy-3-[(N,N-dimethylaminophenyl)methylene]chroman-4-one was found to possess potent inhibitory activity and was comparable to that of the standard, nordihydroguiaretic acid. These results suggest that these homoisoflavonoids, with their potent antioxidant and 5-LOX inhibitory activities, may have useful applications as antioxidants and lead compounds for asthma and inflammatory diseases.
Arkivoc, 2006
An efficient Hantzsch condensation of polyhydroquinoline derivatives was reported via a fourcompo... more An efficient Hantzsch condensation of polyhydroquinoline derivatives was reported via a fourcomponent coupling reaction of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of HClO 4-SiO 2 under solvent-free conditions. Operational simplicity, use of an economically convenient catalyst, high yield, short reaction times are the key features of this protocol.
Synthetic Communications, 2014
ABSTRACT Urea/thiourea have been identified as an effective ammonia surrogate in the construction... more ABSTRACT Urea/thiourea have been identified as an effective ammonia surrogate in the construction of quinazolin-4(3H)-one ring. This strategy afforded a simple and catalyst-free synthesis of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones via the reaction of isatoic anhydride and aryl aldehydes in the presence of urea or thiourea in ethanol. The reaction proceeded well to afford the quinazolin-4(3H)-one or its dihydro derivative, depending on the nature of carbonyl compounds employed.
Russian Journal of Organic Chemistry, 2020
The first stereoselective total synthesis of the linear pentaketide Modiolin has been performed v... more The first stereoselective total synthesis of the linear pentaketide Modiolin has been performed via Jacobsen’ hydrolytic kinetic resolution and 2C-Wittig homologation as key steps.
International Journal of Engineering and Applied Sciences, 2017
Water is an essential component for the survival of the eco systems and all the living organisms ... more Water is an essential component for the survival of the eco systems and all the living organisms on the earth. Due to agricultural activities, rapid industrialization and growth in urban population, the water sources are being contaminated by anthropogenic activities. Keepingnbsp in view the rapid industrialization in East Godavari region, it is proposed to characterize the effluent water generated from the paper industry and ground water collected from the surrounding areas of the industry to assessnbsp the impact of paper industrial effluentnbsp on ground water quality .The present work is focused on characterization of effluent and ground water collectednbsp physiologicalnbsp parameters viz.,pH, EC,TDS,TH, TA, Chloride, Sulphate, Nitrate,nbsp Phosphate, Na, K,Ca,Mg for assessing the chemical contamination of water. Irrigation parameters like, Percent sodium, SAR, RSC, KR and MH are determined to verify the suitability of water for irrigation purposes. Further thenbsp waters are c...
Asian Journal of Chemistry, 2018
Soil is a general term usually denotes the unconsolidated thin, variable layer of mineral and org... more Soil is a general term usually denotes the unconsolidated thin, variable layer of mineral and organic material usually biologically active which covers rest of the earth land surface. Soil properties are sensitive to various changes in the management and can be employed as indicators. In India, large numbers of fertilizers are employed instead of manures as such the crop productivity increases speedily but the quality of soil support decreases. It is difficult to control the adverse effects of the chemical fertilizers to the soil, plants, animals and human being [1,2]. Analysis of soil was carried out for the studies of various parameters like pH, conductivity, TDS, organic carbon, available nitrate nitrogen, calcium and magnesium. Various devastating ecological and human disasters of the last four decades implicate industries as a major contribution to environmental degradation and pollution [3-5].
International Journal of Bioassays, 2017
A novel, cost effective, scalable process for the preparation of chroman epoxides starting from 4... more A novel, cost effective, scalable process for the preparation of chroman epoxides starting from 4-fluorophenol is described. The highlights of the process are single step O-acylation, fries rearrangement, one pot synthesis of claisen condensation, cyclization, reduction, epoxidation with over all yield of 50.9% [(R,S)/(S,R)]-chroman epoxide-A is 33.9% and [(S,S)/(R,R)]-chroman epoxide-B is 17%.
Grasas y Aceites, 2017
In the present study, the supercritical carbon dioxide (CO2) extraction of oil from Simarouba glu... more In the present study, the supercritical carbon dioxide (CO2) extraction of oil from Simarouba gluaca seeds was carried out at varying conditions of pressure (300–500 bar), temperature (50–70 °C) and CO2 flow rate (10–30 g·min-1). The extraction condition for maximum oil yield was obtained at 500 bar pressure, 70 °C and at 30 g·min-1 flow rate of CO2. The extracted oil was analyzed thoroughly for physico-chemical properties and compared with those of conventional solvent extracted oil. An interesting observation is a significant reduction in the phosphorus content of the oil (8.4 mg·kg-1) extracted using supercritical CO2 compared to the phosphorous content of the solvent extracted oil (97 mg·kg-1). Moreover, the content of total tocopherols in supercritically extracted oil (135.6 mg·kg-1) was found to be higher than the solvent extracted oil (111 mg·kg-1). The rest of the physico-chemical properties of the two differently extracted oils matched well with each other. The results indi...
Synthetic Communications, 2013
ABSTRACT A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-... more ABSTRACT A simple and alternative method has been developed for the synthesis of 4-benzylidene-2-phenyl-5(4H)-oxazolones via reactions of hippuric acid with various aldehydes in the presence of 2-chloro-4,6-dimethoxy-1,3,5-triazine/N-methylmorpholine at 75 °C.Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.
Green Chemistry Letters and Reviews, 2012
We have reported an efficient and eco-friendly protocol for the protection of various structurall... more We have reported an efficient and eco-friendly protocol for the protection of various structurally and electronically divergent aryl and aliphatic amines using Cbz-Cl in the presence of polyethylene glycol (PEG)-400 at room temperature. The reaction afforded excellent yields with low as well as high molecular weight PEGs.
Chemistry Letters, 2010
... V. Siddaiah,* GM Basha, G. Padma Rao, U. Viplava Prasad, and R. Suryachendra Rao Department o... more ... V. Siddaiah,* GM Basha, G. Padma Rao, U. Viplava Prasad, and R. Suryachendra Rao Department of Organic Chemistry & FDW, Andhra University, Visakhapatnam 530 003, India ... 11 a) RK Pandey, SP Dagade, RK Upadhyay, MK Dongare, P. Kumar, Arkivoc 2002, Part vii, 28. ...
Catalysis Letters, 2011
Page 1. HClO4-SiO2: An Efficient Reusable Catalyst for the Synthesis of 3,4,5-Trisubstituted 1,2,... more Page 1. HClO4-SiO2: An Efficient Reusable Catalyst for the Synthesis of 3,4,5-Trisubstituted 1,2,4-Triazoles Under Solvent-Free Conditions Vidavalur Siddaiah Gajula Mahaboob Basha Rayavarapu Srinuvasarao Santosh Kumar Yadav ...
Canadian Journal of Chemistry, 2013
A mild and efficient one-flask method has been developed for the synthesis of chromones, isoflavo... more A mild and efficient one-flask method has been developed for the synthesis of chromones, isoflavones, and homoisoflavones from 2-hydroxyacetophenones, deoxybenzoins, and dihydrochalcones, respectively, via one-carbon extension using the complex 2,4,6-trichloro-1,3,5-triazine/dimethylformamide. Deoxybenzoins and dihydrochalcones were prepared in situ by the reaction of readily available substituted phenols with phenylacetic acids and 3-phenylpropanoic acids, respectively. This method allows the synthesis of a wide range of compounds with multiple phenolic hydroxyls and other substituents. The methodology has been applied to the synthesis of three naturally occurring isoflavones such as formononetin (9c), daidzein (9d), and retusin (9h).
Asian Journal of Chemistry, 2017
An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is ... more An efficient method for the synthesis of substituted cinnamic acid and ylidene malanonitriles is developed via Knoevenagel condensation of aromatic aldehydes with malonic acid and malononitrile in the presence of catalytic amounts of DABCO. This method has many advantages, such as mild reaction conditions, excellent yields, short reaction times and no furthur purification required.
Chemical Data Collections, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Chemical Data Collections, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Russian Journal of General Chemistry, 2019
A novel series 3-{2-[(1-aryl-1H-1,2,3-triazol-4-yl)methoxy]-5-fluorophenyl}isoxazoles derivatives... more A novel series 3-{2-[(1-aryl-1H-1,2,3-triazol-4-yl)methoxy]-5-fluorophenyl}isoxazoles derivatives is synthesized from 1-(5-fluoro-2-hydroxyphenyl)ethanone. All the synthesized compounds are characterized by IR, 1 H and 13 C NMR, and mass spectral data, and tested for their in vitro antimicrobial activity against bacterial and fungal organisms.
Journal of Molecular Catalysis A: Chemical, 2006
Substituted coumarins are synthesized from phenols and ethyl acetoacetate or methyl acetoacetate ... more Substituted coumarins are synthesized from phenols and ethyl acetoacetate or methyl acetoacetate via Pechmann condensation using heterogeneous recyclable catalyst (HClO4· SiO2) under solvent-free conditions. This method is simple, cost effective, requires short ...
Journal of Heterocyclic Chemistry, 2013
Bioorganic & Medicinal Chemistry Letters, 2007
Bioorganic & Medicinal Chemistry, 2006
A series of four naturally occurring homoisoflavonoids and eight analogs have been synthesized st... more A series of four naturally occurring homoisoflavonoids and eight analogs have been synthesized starting from an appropriately substituted phenol through chroman-4-one, in four steps. The products were assigned as E-isomers based on NMR spectroscopic data. The E-isomers were converted into Z-isomers by photoisomerization. The E-and Z-isomers showed distinct chemical shifts and the differences between (E) and (Z)-homoisoflavonoids in the proton NMR spectra afford a useful method for ascertaining the stereochemistry. The antioxidant activity of homoisoflavonoids was determined by superoxide (NBT) and DPPH free radical scavenging methods. The analog 7-hydroxy-3-[(3,4,5-trihydroxyphenyl)methylene]chroman-4-one displayed excellent activity followed by sappanone A in both the methods and were several times potent than the commercial antioxidants like BHA, BHT, etc. These compounds were evaluated in vitro for their inhibitory activities against 5-lipoxygenase (5-LOX) enzyme. The analog 7-hydroxy-3-[(N,N-dimethylaminophenyl)methylene]chroman-4-one was found to possess potent inhibitory activity and was comparable to that of the standard, nordihydroguiaretic acid. These results suggest that these homoisoflavonoids, with their potent antioxidant and 5-LOX inhibitory activities, may have useful applications as antioxidants and lead compounds for asthma and inflammatory diseases.
Arkivoc, 2006
An efficient Hantzsch condensation of polyhydroquinoline derivatives was reported via a fourcompo... more An efficient Hantzsch condensation of polyhydroquinoline derivatives was reported via a fourcomponent coupling reaction of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of HClO 4-SiO 2 under solvent-free conditions. Operational simplicity, use of an economically convenient catalyst, high yield, short reaction times are the key features of this protocol.
Synthetic Communications, 2014
ABSTRACT Urea/thiourea have been identified as an effective ammonia surrogate in the construction... more ABSTRACT Urea/thiourea have been identified as an effective ammonia surrogate in the construction of quinazolin-4(3H)-one ring. This strategy afforded a simple and catalyst-free synthesis of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones via the reaction of isatoic anhydride and aryl aldehydes in the presence of urea or thiourea in ethanol. The reaction proceeded well to afford the quinazolin-4(3H)-one or its dihydro derivative, depending on the nature of carbonyl compounds employed.