This document discusses the use of microwaves for synthesis. It provides benefits of microwave synthesis such as faster reactions, less byproducts, and energy efficiency. Demerits include difficulty controlling heat and potential dangers from closed containers. Applications include pharmaceuticals, food processing, chemicals, polymers, and waste management. One example provided is a one-pot solvent-free microwave synthesis of fused pyrimidine diones and triones from barbituric acids, aldehydes, and carbamides/thiocarbamides. Microwave synthesis allows for greener chemistry by preventing waste and enabling inherently safer and more energy efficient reactions.

1. USE OF MICROWAVES
FOR SYNTHESIS
Minal
M.Sc.
chemistry
18000070104
Presented by
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2. Contents
 Introduction
 Benefits of microwave synthesis
 Demerits in microwave synthesis
 Comparison
 Use of microwave in green synthesis
 Application in catalyst and solvent free one pot microwave
synthesis of fused pyrimidine diones and triones
 Reactions and mechanism
 Comparison table
 Conclusion
 References
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3. Introduction
A microwave is a
form of
electmagnetic
energy that falls at
the lower frequency
and of the
electmagnetic
spectrum and is
defined in the 300
to 300,000(MHz)
frequency range.
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4. It utilizes the
ability of mobile
electric charges
in liquid or
conducting ions
in solid to
transform
electromagnetic
energy into heat.
Preparation of a
desired
compound from
available starting
materials via
some (multi-step)
procedure,
involving
microwave
irradiation.
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5. Benefits of MW synthesis
 Faster reactions,lesser byproducts, pure
compounds.
 Energy efficient,rapid energy transfer.
 Easy access to high pressure performance.
 Rapid synthesis results in lesser evaporation
of solvents.
 Absolute control over reaction parameters.
 Selective heating / activation of catalysts.
 Higher temperature (superheating/sealed
vessels).
 Recent simplification of MORE technique
have increased safety and practical utility.
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6. Demerits of MW synthesis
Heat force controlled is
difficult.
Water evaporation
Closed container is
dangerous because it can
blast.
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7. Comparison
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8. Applications of MW assisted
synthesis
• In pharmaceautical powders and
pasteurization of food products.
• In industry its important application is in
preparation of hydrogen cyanide and in
chlorination plant.
• In polymer synthesis.
• Microwave irradiation also used in the waste
management.
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9. Use of microwave in green
synthesis
Green chemistry is the utilization of a set of
principles that reduces or eliminates the use or
generation of hazardous substances in the
design, manufacture and application of
chemical products.
Out of 12 principles of green chemistry ,the
following are taken care through MW synthesis
•Prevention of waste
•Design for energy efficiency
•Less hazardous chemical synthesis
•Inherently safer chemistry for accident
prevention
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10. Solvent free reactions
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11. One pot synthesis
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A one-pot
synthesis means
that a synthesis
involving in
multiple steps
could instead be
done within one
single reaction
flask.

12. Some examples
 Simple microwave assisted method for the
green synthesis of silver and gold
nanoparticles by the reduction of aqueous
metal salt solutions using leaf extract of
the medicinal plant Aerva lanata.
 Synthesis of TiC powders with the
assistance of microwave heating.
 MW heating has received considerable
attention as a promising new method for
the one-pot synthesis of metallic
nanostruture in solution.
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13. Application in catalyst and
solvent free one- pot
microwave synthesis of fused
pyrimidine diones and triones
one pot three components synthesis
of fused pyrimidine diones and triones
have been achieved by reaction of
barbituric acids, aldehydes and
monosubstituted carbamides or
thiocarbamides under microwave
irradiation.
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14.  This method is applicable to the
synthesis of variously substituted
fused pyrimidine diones and triones .
 This method offers substantial
improvements in the reaction rates and
yields, and also avoids the use of
hazardous solvent and catalyst apart
from applicability to the wide variety of
substrates.
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15. Reaction and
mechanism
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17. I. Possible mechanism for formation of 4
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18. Conclusion
MAOS is used rapidly to explore and
increase the diversity of organic
compounds
It is very convenient to
synthesize aromatic and heterocyclic
compounds. In present study, for the
safe , rapid,inexpensive,simple
synthesis of potentially therapeutic
chalcones and heterocyclic
compounds.
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19. References
1. Madura M Sontakke,M G Dhonde , C S Bhaskar & B N
Berad ,Catalyst and solvent free one-pot microwave
synthesis of fused pyrimidine diones and triones ,Indian
Journal Of Chemistry , Vol. 55B, 2016 ,pp. 629-636.
2. https://wiki.anton_paar.com/en/microwave_assisted_synt
hesis/
3. https://www.researchgate.net/publication/279179792_Mi
crowave_chemistry_General__Features_and_Applications
4. https://Slideshare.net/mobile/rahulpandit51/microwave_
assisted_organic_synthesis
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