We demonstrate here the synthesis of octahydroquinazolinone derivatives through one-pot, three-co... more We demonstrate here the synthesis of octahydroquinazolinone derivatives through one-pot, three-component condensation reactions of various aryl aldehydes, with a dimedone and urea in 50 % aqueous hydrotropic solution (Sodium p-Toluene Sulfonate) under microwave irradiation. This method exhibits efficient and environmentally benign methodology with simple reaction workup for the rapid synthesis of library of octahydroquinazolinones. Moreover, the reaction medium can be easily separated from the product and subsequently reused many times. The present method is of great interest in the context of environmentally greener and safer processes.
Ultrasound promoted synthesis of β-amino carbonyl compounds in aqueous hydrotropic medium at ambi... more Ultrasound promoted synthesis of β-amino carbonyl compounds in aqueous hydrotropic medium at ambient temperature is reported. The remarkable features of the new procedure are shorter reaction time, excellent yields in aqueous medium, cleaner reaction profile and simple experimental and work-up procedure.
Supplementary Information Materials and methods Chemicals, reagents, instrument, software, and pr... more Supplementary Information Materials and methods Chemicals, reagents, instrument, software, and preparation of solutions Chemicals and reagents Chemicals and reagents such as Milli-Q Water (TOC: <5ppb), Ammonium acetate (Merck and Sigma Aldrich), Acetonitrile (Merck), Glacial acetic acid (Merck), and Methanol (Merck) were used with high purity HPLC and LC-MS grades. The reference standards of Cinnarizine, Impurity-A, Impurity-B, Impurity-C, Impurity-D, Impurity-E, Cinnamyl Piperazine, Benzhydrol, Methylparaben, and Propylparaben were used in method development and validation. Refer to Table S1 for detailed information on all ten reference standards. The placebos for the tablet, capsule, and oral suspension formulations used in this study are of standard grades. Samples of cinnarizine drug substance, cinnarizine tablets (25mg/tablets), cinnarizine capsules (75mg/ capsule), and cinnarizine oral suspension (75mg/ ml) were used wherever it was applicable. The label claims of methylparaben and propylparaben in cinnarizine 75mg/mL oral suspension were 2.0mg/mL and 0.5mg/mL, respectively.
Research in catalysis particularly cross coupling reactions catalyzed by transition metals is a m... more Research in catalysis particularly cross coupling reactions catalyzed by transition metals is a major field in applied sciences and involves many areas of chemistry. In the last few years, there is upsurge in the area of heterogeneous catalysis for chemical industries. Transition metal chemistry (particularly Pd based) complements traditional functional-group-based chemistry and significantly broadens the scope of organic chemistry. For the past 20 years, numerous research groups have developed new metal complexes and ligands, expanding the scope of these transformations. The importance of these transformations and their impact on synthetic chemistry have been recently recognized by awarding Nobel Prize in Chemistry for the year 2010 to Professor Heck, Negishi and Suzuki jointly.
... DOI: 10.1080/17518253.2011.584217 Santosh Kamble a , Gajanan Rashinkar a , Arjun Kumbhar a &a... more ... DOI: 10.1080/17518253.2011.584217 Santosh Kamble a , Gajanan Rashinkar a , Arjun Kumbhar a & Rajashri Salunkhe a * Available online: 04 Aug 2011. ...
1,8-Dioxo-octahydroxanthene were efficiently prepared by a recyclable carboxyl-functionalized [cm... more 1,8-Dioxo-octahydroxanthene were efficiently prepared by a recyclable carboxyl-functionalized [cmmim] [BF 4 ] Task Specific Ionic Liquid [TSIL] in aqueous media in high yield and the ionic liquid can be recycled at least 6 times without significant loss of activity.
A novel Brønsted acidic supported ionic liquid phase catalyst with pendant ferrocenyl group has b... more A novel Brønsted acidic supported ionic liquid phase catalyst with pendant ferrocenyl group has been synthesized and investigated for the synthesis of homoallylic alcohols from aryl aldehydes and allyltrimethylsilane in THF-H2O as solvent. The key features of the catalyst include rapid reactions with high yields, excellent catalyst recyclability and total stability under open air conditions.
A general, simple, efficient, cost-effective and green procedure for acylation of amines has been... more A general, simple, efficient, cost-effective and green procedure for acylation of amines has been developed by treatment with acetic anhydride is efficiently catalyzed by using intact plant material (aqueous extract of pods of Acacia concinna fruit). Reactions proceed with very good to excellent yields at room temperature.
An extremely efficient, straightforward and green protocol for the synthesis of â-enaminones has ... more An extremely efficient, straightforward and green protocol for the synthesis of â-enaminones has been developed as a consequence of pursuing the emerging routes towards sustainable growth. The green synthesis of â- enaminones was carried out by using natural surfactant solution as a reactionmedium. We have employed the aqueous extract ofmesocarp of fruit of Balanites roxburghii plant which contained natural surfactant as a major component.Avariety of â-enamino ketones are synthesized in quantitative yield under the influence of micelles at room temperature. The reaction proceeds effortlessly in a short reaction time with easy product formation and via environmentally benign method with economic benefits.
A simple and efficient protocol for the ligand-free Mizoroki-Heck coupling reaction of various ar... more A simple and efficient protocol for the ligand-free Mizoroki-Heck coupling reaction of various aryl bromides with different olefins has been reported by using in situ generated PdNPs of size 5-10 nm in aqueous solution of bio-surfactant. The biosurfactant used in this study is a saponin extract of the seeds of pericarps (pods) of the Acacia concinna plant. The in situ generated PdNPs have been characterized by various techniques such as HRTEM, EDS and XPS. The influence of various parameters such as the nature and amount of bases, the nature of Pd precatalysts as well as the effect of temperature has been investigated on Mizoroki-Heck coupling reaction. The generated PdNPs significantly coupled the various aryl bromides with different olefins in aqueous extract of the seeds of pericarps (pods) of the Acacia concinna plant at 100 °C.
: Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting ... more : Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting of 1-methyl imidazole in the matrix of chloropropyl modified sawdust followed by reaction with nickel acetate. The resultant NHC-Ni complex was employed as a heterogenous catalyst for the synthesis of 2-substituted benzoxazoles from benzoxazole and aryl boronic acids following C-H activation strategy. The recycling experiments showed that the complex could be reused for five consecutive runs without significant loss in the yield of products.
We demonstrate here the synthesis of octahydroquinazolinone derivatives through one-pot, three-co... more We demonstrate here the synthesis of octahydroquinazolinone derivatives through one-pot, three-component condensation reactions of various aryl aldehydes, with a dimedone and urea in 50 % aqueous hydrotropic solution (Sodium p-Toluene Sulfonate) under microwave irradiation. This method exhibits efficient and environmentally benign methodology with simple reaction workup for the rapid synthesis of library of octahydroquinazolinones. Moreover, the reaction medium can be easily separated from the product and subsequently reused many times. The present method is of great interest in the context of environmentally greener and safer processes.
Ultrasound promoted synthesis of β-amino carbonyl compounds in aqueous hydrotropic medium at ambi... more Ultrasound promoted synthesis of β-amino carbonyl compounds in aqueous hydrotropic medium at ambient temperature is reported. The remarkable features of the new procedure are shorter reaction time, excellent yields in aqueous medium, cleaner reaction profile and simple experimental and work-up procedure.
Supplementary Information Materials and methods Chemicals, reagents, instrument, software, and pr... more Supplementary Information Materials and methods Chemicals, reagents, instrument, software, and preparation of solutions Chemicals and reagents Chemicals and reagents such as Milli-Q Water (TOC: <5ppb), Ammonium acetate (Merck and Sigma Aldrich), Acetonitrile (Merck), Glacial acetic acid (Merck), and Methanol (Merck) were used with high purity HPLC and LC-MS grades. The reference standards of Cinnarizine, Impurity-A, Impurity-B, Impurity-C, Impurity-D, Impurity-E, Cinnamyl Piperazine, Benzhydrol, Methylparaben, and Propylparaben were used in method development and validation. Refer to Table S1 for detailed information on all ten reference standards. The placebos for the tablet, capsule, and oral suspension formulations used in this study are of standard grades. Samples of cinnarizine drug substance, cinnarizine tablets (25mg/tablets), cinnarizine capsules (75mg/ capsule), and cinnarizine oral suspension (75mg/ ml) were used wherever it was applicable. The label claims of methylparaben and propylparaben in cinnarizine 75mg/mL oral suspension were 2.0mg/mL and 0.5mg/mL, respectively.
Research in catalysis particularly cross coupling reactions catalyzed by transition metals is a m... more Research in catalysis particularly cross coupling reactions catalyzed by transition metals is a major field in applied sciences and involves many areas of chemistry. In the last few years, there is upsurge in the area of heterogeneous catalysis for chemical industries. Transition metal chemistry (particularly Pd based) complements traditional functional-group-based chemistry and significantly broadens the scope of organic chemistry. For the past 20 years, numerous research groups have developed new metal complexes and ligands, expanding the scope of these transformations. The importance of these transformations and their impact on synthetic chemistry have been recently recognized by awarding Nobel Prize in Chemistry for the year 2010 to Professor Heck, Negishi and Suzuki jointly.
... DOI: 10.1080/17518253.2011.584217 Santosh Kamble a , Gajanan Rashinkar a , Arjun Kumbhar a &a... more ... DOI: 10.1080/17518253.2011.584217 Santosh Kamble a , Gajanan Rashinkar a , Arjun Kumbhar a & Rajashri Salunkhe a * Available online: 04 Aug 2011. ...
1,8-Dioxo-octahydroxanthene were efficiently prepared by a recyclable carboxyl-functionalized [cm... more 1,8-Dioxo-octahydroxanthene were efficiently prepared by a recyclable carboxyl-functionalized [cmmim] [BF 4 ] Task Specific Ionic Liquid [TSIL] in aqueous media in high yield and the ionic liquid can be recycled at least 6 times without significant loss of activity.
A novel Brønsted acidic supported ionic liquid phase catalyst with pendant ferrocenyl group has b... more A novel Brønsted acidic supported ionic liquid phase catalyst with pendant ferrocenyl group has been synthesized and investigated for the synthesis of homoallylic alcohols from aryl aldehydes and allyltrimethylsilane in THF-H2O as solvent. The key features of the catalyst include rapid reactions with high yields, excellent catalyst recyclability and total stability under open air conditions.
A general, simple, efficient, cost-effective and green procedure for acylation of amines has been... more A general, simple, efficient, cost-effective and green procedure for acylation of amines has been developed by treatment with acetic anhydride is efficiently catalyzed by using intact plant material (aqueous extract of pods of Acacia concinna fruit). Reactions proceed with very good to excellent yields at room temperature.
An extremely efficient, straightforward and green protocol for the synthesis of â-enaminones has ... more An extremely efficient, straightforward and green protocol for the synthesis of â-enaminones has been developed as a consequence of pursuing the emerging routes towards sustainable growth. The green synthesis of â- enaminones was carried out by using natural surfactant solution as a reactionmedium. We have employed the aqueous extract ofmesocarp of fruit of Balanites roxburghii plant which contained natural surfactant as a major component.Avariety of â-enamino ketones are synthesized in quantitative yield under the influence of micelles at room temperature. The reaction proceeds effortlessly in a short reaction time with easy product formation and via environmentally benign method with economic benefits.
A simple and efficient protocol for the ligand-free Mizoroki-Heck coupling reaction of various ar... more A simple and efficient protocol for the ligand-free Mizoroki-Heck coupling reaction of various aryl bromides with different olefins has been reported by using in situ generated PdNPs of size 5-10 nm in aqueous solution of bio-surfactant. The biosurfactant used in this study is a saponin extract of the seeds of pericarps (pods) of the Acacia concinna plant. The in situ generated PdNPs have been characterized by various techniques such as HRTEM, EDS and XPS. The influence of various parameters such as the nature and amount of bases, the nature of Pd precatalysts as well as the effect of temperature has been investigated on Mizoroki-Heck coupling reaction. The generated PdNPs significantly coupled the various aryl bromides with different olefins in aqueous extract of the seeds of pericarps (pods) of the Acacia concinna plant at 100 °C.
: Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting ... more : Sawdust supported N-heterocyclic carbene-nickel complex has been prepared by covalent grafting of 1-methyl imidazole in the matrix of chloropropyl modified sawdust followed by reaction with nickel acetate. The resultant NHC-Ni complex was employed as a heterogenous catalyst for the synthesis of 2-substituted benzoxazoles from benzoxazole and aryl boronic acids following C-H activation strategy. The recycling experiments showed that the complex could be reused for five consecutive runs without significant loss in the yield of products.
Uploads
Papers by Arjun Kumbhar