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APPLICATIONS. Microwave heating is able to heat the target compounds without heating the entire furnace or oil bath This saves time and energy.
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Microwave heating is able to heat the target compounds without heating the entire furnace or oil bath • This saves time and energy. • However, due to the design of most microwave ovens and to uneven absorption by the object being heated, the microwave field is usually non-uniform and localized super heating occurs
Microwave heating can have certain benefits over conventional ovens: • reaction rate acceleration • milder reaction conditions • higher chemical yield • lower energy usage • different reaction selectivities
It is time saving • Increased reaction rates 1000 fold in best cases • Used to accelerate chemistry in both solution &solid phase reaction • Improved product yields • It can be conducted in either open or closed vessels
Access to synthetic transformations not achievable via conductive heating • Broad dynamic temperature range (45˚c-300˚c) • Green chemistry- reactions in supercritical water or solvent – less reaction • It can be used to accelerate the synthesis of peptides • It is used for parallel synthesis.
Controlled method of heating • Rapid reaction optimization • In organic reactions many reactions has now performed through microwave heating EXAMPLES: Acetylation reaction, Alkylation, Coupling reaction, Condensation reaction, Diel’s alder reaction, Elimination reaction etc
Heterocyclic Nucleus Synthesis Microwave is used in synthesis of • Five-Membered Heterocyclic Rings- Pyrroles, Pyrazoles, Imidazoles, Oxazolines, Triazoles , Isoxazolines etc • Benzo-Derivatives of Five-Membered Rings- Benz-imidazoles, Benz-oxazoles, Benz-thiazoles etc • Six-Membered Rings- Dihydropyridines, Tetrazines, Dihydropyrimidines
Polycyclic Six-Membered Rings- Quinolines, Pyrimido [1, 2-a] pyrimidines • Heterocyclic C-Alkylations, Heterocyclic N-Alkylation’s, Nucleophilic Substitutions, Hetero-Diels-Alder Reactions, Intramolecular Reactions, Intermolecular Reactions, etc
Synthesis of phenytoin by conventionalµwave • In conventional synthesis 2 hrs reflux is needed • In microwave synthesis only 15 minutes is needed • Yield is better in microwave synthesis than in conventional synthesis.
Miscellaneous Microwave assisted Extraction Microwave Ashing Microwave drying
The instrumentation developed for MAOS has more recently found application in what has been traditionally termed the biosciences. These areas include peptide synthesis proteomics and DMPK (dystrophia myotonica protein kinase) .
Recent publications in the field of proteomics have shown the instrumentation used for MAOS can • be used to accelerate tryptic digests with the total time reduced from hours to minutes with a concomitant improvement in coverage. • Highthroughput proteomic applications may require the development of plate-based instrumentation to facilitate the work flow.
APPLICATION IN A GIVEN TEMPERATURE RANGE Coupling reaction Susbstution reaction etc 80-250˚c Super critical water green chemistry Ring expansion -45˚c