Feel free green chemistry ... Safe the environment

1. Department of pharmaceutical sciences
Dr. Harisingh Gour central University, sagar, [M.P.]
GREEN CHEMISTRY
SUBMITTED TO:
DR. ADARSH SAHU
Presented by:
MOHD RASHID
M.Pharma 2nd sem
Y21254018

2. CONTENTS
• DEFINITION
• NEED OF GREEN CHEMISTRY
• PRINCIPLES OF GREEN CHEMISTRY
• USES OF GREEN CHEMISTRY
• MICROWAVE CHEMISTRY
• ULTRA-SOUND MEDIATED REACTIONS
• REFERENCES.
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3. GREEN CHEMISTRY
• 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 .
• Green Chemistry is a recent approach to design of energy
efficient processes and the best form of waste disposal.
• The awareness among the organic chemists to practice green
chemical routes for organic transformations is significantly
increasing in the place of mineral acids, mild solid acids or clays
are used. The reactions are carried out in organized media or in
green solvents.
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4. Green Chemistry Is About
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Cost
Waste
Hazard
Risk
Energy

5. GREEN CHEMISTRY IS ABOUT
• Waste Minimization at Source
• Use of Catalysts in place of Reagents
• Using Non-Toxic Reagents
• Use of Renewable Resources
• Improved Atom Efficiency
• Use of Solvent Free or Recyclable Environmentally Benign
Solvent systems
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6. Why do we need Green Chemistry ?
• Chemistry is undeniably a very prominent part of our daily lives.
• Chemical developments also bring new environmental problems
and harmful unexpected side effects, which result in the need for
‘greener’ chemical products.
-A famous example is the pesticide DDT.
• Hundreds of tons of hazardous waste are released to the air, water
and land by industry every hour of every day. The chemical industry
is the biggest source of such waste.
• In recent years, pollution control board regulated to reduce
harmful emissions , effluents and workers safety.
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8. The 12 Principles of Green Chemistry
1. Prevention
– It is better to prevent waste than to treat or clean up waste after it has been created.
2. Atom Economy
– Synthetic methods should be designed to maximise the incorporation of all materials
used in the process into the final product.
3. Less Hazardous Chemical Synthesis
– Wherever practicable, synthetic methods should be designed to use and generate
substances that possess little or no toxicity to people or the environment.
4. Designing Safer Chemicals
– Chemical products should be designed to effect their desired function while minimising
their toxicity.
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9. The 12 Principles of Green Chemistry
5. Safer Solvents and Auxiliaries
– The use of auxiliary substances (e.g., solvents or separation agents) should be made
unnecessary whenever possible and innocuous when used.
6. Design for Energy Efficiency
– Energy requirements of chemical processes should be recognised for their
environmental and economic impacts and should be minimised. If possible, synthetic
methods should be conducted at ambient temperature and pressure.
7. Use of Renewable Feedstocks
– A raw material or feedstock should be renewable rather than depleting whenever
technically and economically practicable.
8. Reduce Derivatives
– Unnecessary derivatization (use of blocking groups, protection/de-protection, and
temporary modification of physical/chemical processes) should be minimised or avoided
if possible, because such steps require additional reagents and can generate waste.
9

10. The 12 Principles of Green Chemistry
9. Catalysis
– Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
10. Design for Degradation
– Chemical products should be designed so that at the end of their function they break
down into innocuous degradation products and do not persist in the environment.
11. Real-time Analysis for Pollution Prevention
– Analytical methodologies need to be further developed to allow for real-time, in-process
monitoring and control prior to the formation of hazardous substances.
12. Inherently Safer Chemistry for Accident Prevention
– Substances and the form of a substance used in a chemical process should be chosen to
minimise the potential for chemical accidents, including releases, explosions, and fires.
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11. Production of allyl alcohol
• Traditional route: Alkaline hydrolysis of allyl chloride, which generates the product and hydrochloric
acid as a by-product
• Greener route, to avoid chlorine: Two-step using propylene (CH2=CHCH3), acetic acid (CH3COOH) and
oxygen (O2)
• Added benefit: The acetic acid produced in the 2nd reaction can be recovered and used again for the
1st reaction, leaving no unwanted by-product.
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C
H
2
=
C
H
C
H
2
O
C
O
C
H
3
+
H
2
O C
H
2
=
C
H
C
H
2
O
H
+
C
H
3
C
O
O
H
C
H
2
=
C
H
C
H
3
+
C
H
3
C
O
O
H
+
1
/
2
O
2 C
H
2
=
C
H
C
H
2
O
C
O
C
H
3
+
H
2
O
C H 2 = C H C H 2 C l + H 2 O C H 2 = C H C H 2 O H + H C l
p r o b l e m p r o d u c t

12. Production of styrene
• Traditional route: Two-step method starting with benzene, (which is carcinogenic) and ethylene
to form ethylbenzene, followed by dehydrogenation to obtain styrene
1ST STEP
2ND STEP
• Greener route: To avoid benzene, start with xylene (cheapest source of aromatics and
environmentally safer than benzene).
• Another option, still under development, is to start with toluene (benzene ring with CH3 tail).
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+ H 2 C = C H 2
c a ta y st
C H 2 C H 3
e th y lb e n z e n e
c
a
t
a
y
s
t
C
H
=
C
H
2
C
H
2
-
C
H
3
e
t
h
y
l
b
e
n
z
e
n
e
s
t
y
r
e
n
e

13. The major uses of GREEN CHEMISTRY
• Energy
• Global Change
• Resource Depletion
• Food Supply
• Toxics in the Environment
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14. MICROWAVE CHEMISTRY
• Microwave chemistry is the science of applying microwave
radiation to chemical reactions.
• Microwaves act as high frequency electric fields and will
generally heat any material containing mobile electric
charges, such as polar molecules in a solvent or conducting
ions in a solid.
• Polar solvents are heated as their component molecules are
forced to rotate with the field and lose energy in collisions.
• Semiconducting and conducting samples heat when ions or
electrons within them forman electric current and energy is 14

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16. • Microwave heating in the laboratory began to gain wide
acceptance following papers in 1986, although the use of
microwave heating in chemical modification can be traced back
to the 1950s.
• Although occasionally known by such acronyms as MADS
(Microwave Assisted Organic Synthesis), MEC(Microwave-
Enhanced Chemistry) or MORE synthesis (Microwave-organic
Reaction Enhancement), these acronyms have had little
acceptance outside a small number of groups.
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17. Microwave Assisted Synthesis
• The development of the technology for organic Chemistry
has been rather slow compared to inorganic, computational
and combinatorial chemistry
• This slow uptake of the technology has been principally
attributed to its lack of controllability and reproducibility,
safety aspects and a generally low degree of understanding of
the basics of microwave dielectric heating
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18. Why Microwave assisted synthesis?
• Short reaction times
• Easy work-up procedure
• Reaction may be carried out in the presence of solvent
• Solvent free technique is facilitated
• Ease of synthesis of libraries of compounds
• The availability of commercial microwave equipment intended
for organic chemistry
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23. Ultrasound mediated reaction
• This is very popular technique for promoting various chemical
reactions since the decade 1990-1999.
• The application of ultrasound has been useful in accelerating
dissolution, enhancing the reaction rates, and renewing the surface
of a solid reactant or catalyst in a variety of reaction systems.
• In recent years, the effect of ultrasonic energies in organic
synthesis (homogeneous and heterogeneous reactions) has widely
increased The use of ultrasound in chemical reactions in solution
provides specific activation based on a physical phenomenon.
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24. • Ultrasound is sound waves with
frequencies higher than the
upper audible limit of human
hearing. Ultrasound is different
from 'normal' (audible sound in
its physical properties except in
that humans cannot hear it.
• This limit varies from person to
person and is approximately 20
kilohertz (20,000 hertz) in
healthy, young adults. Ultrasound
devices operate with frequency
from 20 kHz up to several
gigahertz.
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25. Ultrasonics/Sonochemistry Synthesis
Applications in Organic Synthesis
1. Homogeneous Sonochemistry
- Aqueous medium
-Non-aqueous media
2. Heterogeneous Sonochemitsry
-Phase Transfer Catalysis
-Reactions with metals
- Heterogeneous Catalysis
3. Enzyme reactions
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28. Conclusion
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Green chemistry Not a solution
to all environmental problems But
the most fundamental approach to
preventing pollution.
“If the facts don’t fit the theory ,
change the facts “ – Albert Einstein

29. REFERENCES
• "The 12 principles of green chemistry" United states environmrental protection agency.
Retrieved 2006-07-31.
• http://en.wikipedia.org/wiki/Green_chemistryDoi:10.1021/ed100892p
• http://www.greeningschools.org/docs/twelveprinciplesofgreenchemistry.pdf
• http://www.towson.edu/saacs/green.htm
• http://web.njit.edu/~mitra/green chemistry/Green chemiatry
• http://www2.gvsu.edu/gilliamj/Chemistry.htm
• http://profmaster.blogspot.com/2007/06/green-chemistry-12-rules.html
• http://greenchemistry.yale.edu/javascript/tinymce/plugins/filemanager/files/principles-
of-green-chemistry.pdf
• http://academic.scranton.edu/faculty/cannm1/intro.html
• Robert thornton Morrison, Robert Neilson boyd and Saibal Kanti Bhattacharjee. "organic
chemistry" seventh edition pg. no. 1419- 1427.
• http://www.organic-chemistry.org/topics/green-chemistry.shtm
• http://pubs.rsc.org/en/journals/journalissues/ge
• G.-y. Bai, K. Xu, G.-f. Chen, Y.-h. Yang, T.-y. Li, Synthesis, 2011, 1599-1603.22) M. C.
Wilkinson, Org. Lett., 2011, 13, 2232-2235
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“Learn from yesterday ,live for today, hope for tomorrow.
The important thing is to not stop questioning “ - Albert Einstein