APPLICATIONS OF MICROWAVE IRRADIATIONS

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APPLICATIONS
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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

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• Microwave heating can have certain benefits over
  conventional ovens
• reaction rate acceleration
• milder reaction conditions
• higher chemical yield
• lower energy usage
• different reaction selectivities 

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• 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

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• Access to synthetic transformations not
  achievable via conductive heating
• Broad dynamic temperature range (45c-300c)
• 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.

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• 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, Diels alder
  reaction, Elimination reaction etc

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• 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

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• Polycyclic Six-Membered Rings- Quinolines,
  Pyrimido 1, 2-a pyrimidines
• Heterocyclic C-Alkylations, Heterocyclic
  N-Alkylations, Nucleophilic Substitutions,
  Hetero-Diels-Alder Reactions, Intramolecular
  Reactions, Intermolecular Reactions, etc

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Synthesis of phenytoin by conventionalmicrowave

• 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.

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• Miscellaneous
• Microwave assisted Extraction
• Microwave Ashing
• Microwave drying

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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) .
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• 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.

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APPLICATION IN A GIVEN TEMPERATURE RANGE
Coupling reaction Susbstution reaction
etc 80-250c
Super critical water green chemistry
Ring expansion -45c
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