APPLICATIONS
 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˚c300˚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- Benzimidazoles, 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
conventional&microwave
 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
Ring expansion -45˚c
Coupling reaction
Susbstution reaction etc Super critical water
green chemistry
80-250˚c