PRASHANT B HIREMATH - Academia.edu (original) (raw)
Papers by PRASHANT B HIREMATH
Indian Journal of Chemistry -Section B
A simple, solvent-free, faster and mechanochemical approach for the N-tert-butoxycarbonylation of... more A simple, solvent-free, faster and mechanochemical approach for the N-tert-butoxycarbonylation of amines catalyzed by copper iodide nanoparticles as a recyclable catalyst is described. The advantages of this method are simplicity, shorter reaction time (5-15 min), a cost-effective catalyst, and excellent product isolation (82-92%). N-Boc protection of various structurally diverse aliphatic, aromatic, and heterocyclic amines have been carried out with (Boc) 2 O with 10 mol% catalyst under pestle mortar grinding under solvent-free conditions. The catalyst possesses distinct advantages, ease of handling as well as removal, cleaner reactions, high activity, and environmentally benign. The final product has been characterised by various spectroscopic techniques.
Indian Journal of Chemistry -Section B
Current Organocatalysis, 2021
Background: The present work describes an eco-friendly and sustainable approach for the Knoevenag... more Background: The present work describes an eco-friendly and sustainable approach for the Knoevenagel condensation of an aromatic aldehyde with ethyl cyanoacetate, and salicylaldehyde with Meldrum acid for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) derivatives, respectively. The reaction was performed under green catalytic media-Water Extract of Watermelon Fruit Peel Ash (WEWFPA), which is an eco-friendly protocol derived from the agro-waste feedstock. Various protocols have been reported for the synthesis of Knoevenagel condensation reaction using a hazardous catalyst or/and solvents found toxic to the environment, requiring longer reaction time, giving poor yield, and requiring purification of the final product. The method at hand provides several added advantages like: being a completely green method, economic, inexpensive catalyst, and the final product isolated is in pure form with good yield. Objective: The objective of the stud...
A greener, economic and efficient approach for Knoevenagel condensation of substituted aromatic a... more A greener, economic and efficient approach for Knoevenagel condensation of substituted aromatic as well as heteroaromatic aldehydes with malononitrile catalyzed by water extract of banana (WEB) under grindstone method at room temperature is described. The total process is advantageous over conventional methods that involve reflux, heating and expensive approaches and also the reaction time is reduced. It is found that the reaction is clean with the separation of the solid product during grinding process and reaction can be carried out without use of organic solvent as well as expensive catalyst. The final product is isolated by simple filtration and characterized by several spectroscopic methods for the confirmation of the products.
A greener, economic and eco-friendly method for Knoevenagel condensation of aromatic aldehyde, sa... more A greener, economic and eco-friendly method for Knoevenagel condensation of aromatic aldehyde, salicylaldehyde with active methylene compounds like malononitrile and Meldrum's acid to synthesize benzylidinemalononitrile and 3-carboxy coumarin derivatives respectively is demonstrated. The reaction has been carried out in the absence of external base using agro-waste sourced green catalyst WENBA {Water Extract of Nilgiri Bark Ash (Eucalyptus)} as an efficient natural catalytic medium. WENBA is a novel, ecologically safe and inexpensive green catalyst obtained from the agro-waste feedstock. The synthesized compounds benzylidinemalononitrile and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) backbone have multiple applications in medicinal chemistry for the synthesis of bioactive molecules. Thus, a wide number of methodologies have been developed for the synthesis of this class of organic molecules. However, some of the methods reported are associated with hazardous materials and are toxic to the environment. They have longer reaction times, poor yields, and with lower purity of final isolated compound. In spite of a large number of methodologies available for this bioactive molecule synthesis, there is still demand for the development of newer reagents, which give environmentally friendly protocols, mild reaction conditions, inexpensive catalyst and final product isolation in pure form with good yields.
In the present investigation an attempt has been made on the study of friction performance of LM6... more In the present investigation an attempt has been made on the study of friction performance of LM6 reinforcing with varying SiC content composite for varying process parameters. The composite is prepared by stir casting process in an electric melting furnace. The tribological tests are carried out on LM6 with varying SiC for testing the friction property of the material. The experimental study is performed varying Normal pressure, speed and wt % of SIC. The design of experiment approach was employed to acquire data in controlled way using Taguchi method. An orthogonal array, signal-to-noise ratio and analysis of variance were employed to optimize the wear rate and frictional force of LM6-SiC composite. The mathematical model was obtained to determine the friction performance of Al-SiC composite. It is observed that sliding speed influence the friction behaviour, significantly.
Current Organocatalysis, 2021
Background: Present-day chemists are more interested in developing and using green chemistry prot... more Background: Present-day chemists are more interested in developing and using green chemistry protocol for various organic transformations, which employ natural feedstock extracts, and solvent-free, and greener catalysts; they are well known for their non-hazardous nature and have replaced many organic and inorganic based catalysts. In literature, the reported homogenous catalytic approaches have been employed for various bioactive heterocycle syntheses, which follow the green chemistry principle established for various organic transformations catalyzed by WERSA, BFE, WEPPA, WEMFSA, WEMPA, and Eichhorniacrassipes. Among them, 2-aryl benzimidazole derivatives have emerged as prominent molecules with a wide variety of applications in biological and material science. Methods: The agro-waste sourced from the banana peel is utilized for the preparation of BPAE catalyst, which is employed for the synthesis of 2-aryl benzimidazole derivatives under ultrasound waves at room temperature. Resu...
Current Microwave Chemistry, 2020
Background: Amide bond plays a key role in medicinal chemistry, and the analysis of bioactive mol... more Background: Amide bond plays a key role in medicinal chemistry, and the analysis of bioactive molecular database revealed that the carboxamide group appears in more than 25% of the existing database drugs. Typically amide bonds are formed from the union of carboxylic acid and amine; however, the product formation does not occur spontaneously. Several synthetic methods have been reported for amide bond formation in literature. Present work demonstrated simple and eco-friendly amide bond formation using carboxylic acid and primary amines through in situ generation of O-acylurea. The reaction was found to be more efficient, faster reaction rate; simple work-up gave pure compound isolation in moderate to excellent yield using microwave irradiation as compared to conventional heating. Methods: Developed one-pot synthesis of amide compounds using agro-waste derived greener catalyst under microwave irradiation. Results: Twenty amide bond containing organic compounds are synthesized from ca...
![Research paper thumbnail of Microwave-Accelerated Facile Synthesis of 1H-Pyrazolo[1,2-b]Phthalazine-5,10-Dione Derivatives Catalyzed by WEMPA](https://attachments.academia-assets.com/103059983/thumbnails/1.jpg)
](Polycyclic Aromatic Compounds, 2020
An efficient and rapid one-pot multicomponent synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dio... more An efficient and rapid one-pot multicomponent synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones through condensation of aldehyde, malononitrile and phthalhydrazide catalyzed by agro-waste solvent catalyst-derived water extract of mango peel ash (WEMPA) under microwave irradiation is described. Further, the catalyst is prepared from agricultural waste and characterized for elemental composition by different techniques such as SEM-EDX, XRD and flame photometry. This green synthetic approach offers various advantages such as inexpensive, abundantly available source, shorter reaction time (6-8 min), good-to-excellent yield (83%-89%), simple workup and a sustainable alternative method to the existing protocols. All the synthesized compounds (4a-l) was confirmed by FT-IR, 1 H-NMR, 13 C-NMR and LC-MS.
Emerging Materials Research, 2020
Mineral admixed or blended concretes require more time to attain the desired strength. The presen... more Mineral admixed or blended concretes require more time to attain the desired strength. The present investigation proposes new techniques for enhancing the early-strength development of blended conc...
GLOBAL JOURNAL FOR RESEARCH ANALYSIS, 2019
BACKGROUND: Road Trafc Accidents are the leading cause of unnatural deaths in the world and a ma... more BACKGROUND: Road Trafc Accidents are the leading cause of unnatural deaths in the world and a major burden on the world`s economy. Better road safety measures and awareness campaign such as sensitization program will help to reduce morbidity, mortality, disability and economic impact of road trafc accidents. The study was aimed to evaluate the effectiveness of sensitizing program and to associate selected demographic variables of adolescents with the knowledge, on prevention of road trafc accidents. METHODOLOGY: Pre-experimental research study with pre and post-test group. A structured knowledge questionnaire used to obtain data from 60 adolescents samples. RESULT: The post test ndings shows that the calculated mean was 25.20 compared with pretest mean i.e. 18.22. The calculated paired t test value [t(59,0.05)=10.84 >2.00] is higher than the table value, which shows that the sensitizing program was very effective. The association between the level of knowledge and demographic...
Asian Journal of Chemistry, 2018
Development of alternative method that use environmentally benign solvents and biodegradable, non... more Development of alternative method that use environmentally benign solvents and biodegradable, non-toxic chemical alternative to pollution and toxic chemicals for the organic reaction are emerging in recent years as a green protocol in organic synthesis [1]. Recently, use of agro waste stuff [2] as chemical surrogates has become one of the most emerging in research endeavours for organic chemists. Researchers also reported several agro waste stuff extracted were employed for many organic syntheses and observed successful alternative replacement of many toxic and environmentally causing solvent. Some of the recent reported extracts are water extract of papaya bark ash (WEPBA) [3], water extract of banana peel ash (WEBPA) [4], water extract of rice straw ash (WERSA) [5], etc. These sustainable technologies protect environment and human health by an economically safer approach. It focuses pollution free, environmentally friendly design on production and use of alternative chemical solvent in economical feasibility. However, use of solvent remain a constant source of concern in organic synthesis as it gives toxic and hazardous in storing and waste solvent disposal issues. Solvents are still preferred on account of their easy separation and evaporation, which helps in extraction and separation of many compound which are thermally sensitive reactants. Therefore, in recent years the chemical synthesis based solvent free or neat condition [6] is the best alternative for these issues, as the replace of toxic solvent to simple water extract makes a protocol green.
Current Microwave Chemistry, 2019
Background:The agricultural wastes as a source offer an excellent alternative to replace many tox... more Background:The agricultural wastes as a source offer an excellent alternative to replace many toxic and environmentally hazardous catalysts, due to their least toxicity, ease of biodegradability, and ability to act as a greener catalytic medium. Some of the agro-waste based catalysts reported are BFE, WERSA, WEB, and WEPBA. 2-Amino-4H-chromene derivatives are promising biologically potent heterocyclic compounds, due to their medicinal applications such as antimicrobial, anti-inflammatory, antibacterial, antiviral, anticancer, antidiuretic, anticoagulant and antianaphylactic activities. The present work describes a microwave accelerated, efficient, eco-friendly and economical approach for the synthesis of 2-amino-4H-chromenes through condensation of substituted arylaldehyde, malononitrile and resorcinol/naphthol catalyzed water extract of pomegranate peel ash (WEPPA) under microwave irradiation. The reaction completed within 3-6 min with good to excellent yield of product isolation. ...
Materials Today: Proceedings, 2017
Reactive Powder Concrete (RPC) is a form of Ultra High Performance Concrete (UHPC). The main cons... more Reactive Powder Concrete (RPC) is a form of Ultra High Performance Concrete (UHPC). The main constituents of RPC are cement, sand, silica fume, steel fiber and quartz powder with minimal water to binder ratio, without coarse aggregate. Due to its dense microstructure, RPC exhibit superior properties such as higher strength, durability and long term stability. Earlier researchers have produced RPC with Compressive strength up to 800 MPa and flexural strength of 75 MPa. In the present study, locally available materials are used to produce RPC of different mix proportions. The main objective is to study the effect of different curing regimes on the strength of RPC. The durability study is also carried out by way of accelerated corrosion test and acid test. Results have shown considerable enhancement in compressive strength when RPC specimen were subjected to hot air curing of different durations. RPC specimen cured under hot air curing and steam curing shown better performance compared to normal curing and air curing. Also RPC has shown better resistance to sulphate attack; further the rate of corrosion is low compared to high performance concrete.
Construction and Building Materials, 2017
h i g h l i g h t s Efficiency of various curing regimes have been compared. Curing temperature h... more h i g h l i g h t s Efficiency of various curing regimes have been compared. Curing temperature has significant effect on strength development. Ultra high strength is achieved under combined curing regime. Formation of strength enhancing compounds is discerned with SEM and XRD.
Indian Journal of Chemistry -Section B
A simple, solvent-free, faster and mechanochemical approach for the N-tert-butoxycarbonylation of... more A simple, solvent-free, faster and mechanochemical approach for the N-tert-butoxycarbonylation of amines catalyzed by copper iodide nanoparticles as a recyclable catalyst is described. The advantages of this method are simplicity, shorter reaction time (5-15 min), a cost-effective catalyst, and excellent product isolation (82-92%). N-Boc protection of various structurally diverse aliphatic, aromatic, and heterocyclic amines have been carried out with (Boc) 2 O with 10 mol% catalyst under pestle mortar grinding under solvent-free conditions. The catalyst possesses distinct advantages, ease of handling as well as removal, cleaner reactions, high activity, and environmentally benign. The final product has been characterised by various spectroscopic techniques.
Indian Journal of Chemistry -Section B
Current Organocatalysis, 2021
Background: The present work describes an eco-friendly and sustainable approach for the Knoevenag... more Background: The present work describes an eco-friendly and sustainable approach for the Knoevenagel condensation of an aromatic aldehyde with ethyl cyanoacetate, and salicylaldehyde with Meldrum acid for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) derivatives, respectively. The reaction was performed under green catalytic media-Water Extract of Watermelon Fruit Peel Ash (WEWFPA), which is an eco-friendly protocol derived from the agro-waste feedstock. Various protocols have been reported for the synthesis of Knoevenagel condensation reaction using a hazardous catalyst or/and solvents found toxic to the environment, requiring longer reaction time, giving poor yield, and requiring purification of the final product. The method at hand provides several added advantages like: being a completely green method, economic, inexpensive catalyst, and the final product isolated is in pure form with good yield. Objective: The objective of the stud...
A greener, economic and efficient approach for Knoevenagel condensation of substituted aromatic a... more A greener, economic and efficient approach for Knoevenagel condensation of substituted aromatic as well as heteroaromatic aldehydes with malononitrile catalyzed by water extract of banana (WEB) under grindstone method at room temperature is described. The total process is advantageous over conventional methods that involve reflux, heating and expensive approaches and also the reaction time is reduced. It is found that the reaction is clean with the separation of the solid product during grinding process and reaction can be carried out without use of organic solvent as well as expensive catalyst. The final product is isolated by simple filtration and characterized by several spectroscopic methods for the confirmation of the products.
A greener, economic and eco-friendly method for Knoevenagel condensation of aromatic aldehyde, sa... more A greener, economic and eco-friendly method for Knoevenagel condensation of aromatic aldehyde, salicylaldehyde with active methylene compounds like malononitrile and Meldrum's acid to synthesize benzylidinemalononitrile and 3-carboxy coumarin derivatives respectively is demonstrated. The reaction has been carried out in the absence of external base using agro-waste sourced green catalyst WENBA {Water Extract of Nilgiri Bark Ash (Eucalyptus)} as an efficient natural catalytic medium. WENBA is a novel, ecologically safe and inexpensive green catalyst obtained from the agro-waste feedstock. The synthesized compounds benzylidinemalononitrile and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) backbone have multiple applications in medicinal chemistry for the synthesis of bioactive molecules. Thus, a wide number of methodologies have been developed for the synthesis of this class of organic molecules. However, some of the methods reported are associated with hazardous materials and are toxic to the environment. They have longer reaction times, poor yields, and with lower purity of final isolated compound. In spite of a large number of methodologies available for this bioactive molecule synthesis, there is still demand for the development of newer reagents, which give environmentally friendly protocols, mild reaction conditions, inexpensive catalyst and final product isolation in pure form with good yields.
In the present investigation an attempt has been made on the study of friction performance of LM6... more In the present investigation an attempt has been made on the study of friction performance of LM6 reinforcing with varying SiC content composite for varying process parameters. The composite is prepared by stir casting process in an electric melting furnace. The tribological tests are carried out on LM6 with varying SiC for testing the friction property of the material. The experimental study is performed varying Normal pressure, speed and wt % of SIC. The design of experiment approach was employed to acquire data in controlled way using Taguchi method. An orthogonal array, signal-to-noise ratio and analysis of variance were employed to optimize the wear rate and frictional force of LM6-SiC composite. The mathematical model was obtained to determine the friction performance of Al-SiC composite. It is observed that sliding speed influence the friction behaviour, significantly.
Current Organocatalysis, 2021
Background: Present-day chemists are more interested in developing and using green chemistry prot... more Background: Present-day chemists are more interested in developing and using green chemistry protocol for various organic transformations, which employ natural feedstock extracts, and solvent-free, and greener catalysts; they are well known for their non-hazardous nature and have replaced many organic and inorganic based catalysts. In literature, the reported homogenous catalytic approaches have been employed for various bioactive heterocycle syntheses, which follow the green chemistry principle established for various organic transformations catalyzed by WERSA, BFE, WEPPA, WEMFSA, WEMPA, and Eichhorniacrassipes. Among them, 2-aryl benzimidazole derivatives have emerged as prominent molecules with a wide variety of applications in biological and material science. Methods: The agro-waste sourced from the banana peel is utilized for the preparation of BPAE catalyst, which is employed for the synthesis of 2-aryl benzimidazole derivatives under ultrasound waves at room temperature. Resu...
Current Microwave Chemistry, 2020
Background: Amide bond plays a key role in medicinal chemistry, and the analysis of bioactive mol... more Background: Amide bond plays a key role in medicinal chemistry, and the analysis of bioactive molecular database revealed that the carboxamide group appears in more than 25% of the existing database drugs. Typically amide bonds are formed from the union of carboxylic acid and amine; however, the product formation does not occur spontaneously. Several synthetic methods have been reported for amide bond formation in literature. Present work demonstrated simple and eco-friendly amide bond formation using carboxylic acid and primary amines through in situ generation of O-acylurea. The reaction was found to be more efficient, faster reaction rate; simple work-up gave pure compound isolation in moderate to excellent yield using microwave irradiation as compared to conventional heating. Methods: Developed one-pot synthesis of amide compounds using agro-waste derived greener catalyst under microwave irradiation. Results: Twenty amide bond containing organic compounds are synthesized from ca...
Polycyclic Aromatic Compounds, 2020
An efficient and rapid one-pot multicomponent synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dio... more An efficient and rapid one-pot multicomponent synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones through condensation of aldehyde, malononitrile and phthalhydrazide catalyzed by agro-waste solvent catalyst-derived water extract of mango peel ash (WEMPA) under microwave irradiation is described. Further, the catalyst is prepared from agricultural waste and characterized for elemental composition by different techniques such as SEM-EDX, XRD and flame photometry. This green synthetic approach offers various advantages such as inexpensive, abundantly available source, shorter reaction time (6-8 min), good-to-excellent yield (83%-89%), simple workup and a sustainable alternative method to the existing protocols. All the synthesized compounds (4a-l) was confirmed by FT-IR, 1 H-NMR, 13 C-NMR and LC-MS.
Emerging Materials Research, 2020
Mineral admixed or blended concretes require more time to attain the desired strength. The presen... more Mineral admixed or blended concretes require more time to attain the desired strength. The present investigation proposes new techniques for enhancing the early-strength development of blended conc...
GLOBAL JOURNAL FOR RESEARCH ANALYSIS, 2019
BACKGROUND: Road Trafc Accidents are the leading cause of unnatural deaths in the world and a ma... more BACKGROUND: Road Trafc Accidents are the leading cause of unnatural deaths in the world and a major burden on the world`s economy. Better road safety measures and awareness campaign such as sensitization program will help to reduce morbidity, mortality, disability and economic impact of road trafc accidents. The study was aimed to evaluate the effectiveness of sensitizing program and to associate selected demographic variables of adolescents with the knowledge, on prevention of road trafc accidents. METHODOLOGY: Pre-experimental research study with pre and post-test group. A structured knowledge questionnaire used to obtain data from 60 adolescents samples. RESULT: The post test ndings shows that the calculated mean was 25.20 compared with pretest mean i.e. 18.22. The calculated paired t test value [t(59,0.05)=10.84 >2.00] is higher than the table value, which shows that the sensitizing program was very effective. The association between the level of knowledge and demographic...
Asian Journal of Chemistry, 2018
Development of alternative method that use environmentally benign solvents and biodegradable, non... more Development of alternative method that use environmentally benign solvents and biodegradable, non-toxic chemical alternative to pollution and toxic chemicals for the organic reaction are emerging in recent years as a green protocol in organic synthesis [1]. Recently, use of agro waste stuff [2] as chemical surrogates has become one of the most emerging in research endeavours for organic chemists. Researchers also reported several agro waste stuff extracted were employed for many organic syntheses and observed successful alternative replacement of many toxic and environmentally causing solvent. Some of the recent reported extracts are water extract of papaya bark ash (WEPBA) [3], water extract of banana peel ash (WEBPA) [4], water extract of rice straw ash (WERSA) [5], etc. These sustainable technologies protect environment and human health by an economically safer approach. It focuses pollution free, environmentally friendly design on production and use of alternative chemical solvent in economical feasibility. However, use of solvent remain a constant source of concern in organic synthesis as it gives toxic and hazardous in storing and waste solvent disposal issues. Solvents are still preferred on account of their easy separation and evaporation, which helps in extraction and separation of many compound which are thermally sensitive reactants. Therefore, in recent years the chemical synthesis based solvent free or neat condition [6] is the best alternative for these issues, as the replace of toxic solvent to simple water extract makes a protocol green.
Current Microwave Chemistry, 2019
Background:The agricultural wastes as a source offer an excellent alternative to replace many tox... more Background:The agricultural wastes as a source offer an excellent alternative to replace many toxic and environmentally hazardous catalysts, due to their least toxicity, ease of biodegradability, and ability to act as a greener catalytic medium. Some of the agro-waste based catalysts reported are BFE, WERSA, WEB, and WEPBA. 2-Amino-4H-chromene derivatives are promising biologically potent heterocyclic compounds, due to their medicinal applications such as antimicrobial, anti-inflammatory, antibacterial, antiviral, anticancer, antidiuretic, anticoagulant and antianaphylactic activities. The present work describes a microwave accelerated, efficient, eco-friendly and economical approach for the synthesis of 2-amino-4H-chromenes through condensation of substituted arylaldehyde, malononitrile and resorcinol/naphthol catalyzed water extract of pomegranate peel ash (WEPPA) under microwave irradiation. The reaction completed within 3-6 min with good to excellent yield of product isolation. ...
Materials Today: Proceedings, 2017
Reactive Powder Concrete (RPC) is a form of Ultra High Performance Concrete (UHPC). The main cons... more Reactive Powder Concrete (RPC) is a form of Ultra High Performance Concrete (UHPC). The main constituents of RPC are cement, sand, silica fume, steel fiber and quartz powder with minimal water to binder ratio, without coarse aggregate. Due to its dense microstructure, RPC exhibit superior properties such as higher strength, durability and long term stability. Earlier researchers have produced RPC with Compressive strength up to 800 MPa and flexural strength of 75 MPa. In the present study, locally available materials are used to produce RPC of different mix proportions. The main objective is to study the effect of different curing regimes on the strength of RPC. The durability study is also carried out by way of accelerated corrosion test and acid test. Results have shown considerable enhancement in compressive strength when RPC specimen were subjected to hot air curing of different durations. RPC specimen cured under hot air curing and steam curing shown better performance compared to normal curing and air curing. Also RPC has shown better resistance to sulphate attack; further the rate of corrosion is low compared to high performance concrete.
Construction and Building Materials, 2017
h i g h l i g h t s Efficiency of various curing regimes have been compared. Curing temperature h... more h i g h l i g h t s Efficiency of various curing regimes have been compared. Curing temperature has significant effect on strength development. Ultra high strength is achieved under combined curing regime. Formation of strength enhancing compounds is discerned with SEM and XRD.