relevance of 12 principles of green chemistry in pharma
TRANSCRIPT
Prof. Bhalchandra M. Bhanage
Head, Department of Chemistry
Institute of Chemical Technology,
Mumbai, India.
E-mail : [email protected]
1
@Industrial Seminar on “Green Chemistry & Green Engineering” for Pharma API
Industry, on 27 and 28th April 2015 at at Hotel Green Park, Greenlands, Begumpet,
Hyderabad, Organized by Green ChemisTree Foundation
Relevance of 12 Principles of Green Chemistry
in Pharma API Manufacturing
GREEN CHEMISTRY
DEFINITIONGreen Chemistry is the utilisation 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 ABOUT
• Waste Minimisation 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
1. PreventionIt is better to prevent waste than to treat or clean up waste after it has been created.
2. Atom EconomySynthetic methods should be designed to maximise the incorporation of all materialsused in the process into the final product.
3. Less Hazardous Chemical SynthesisWherever practicable, synthetic methods should be designed to use and generatesubstances that possess little or no toxicity to people or the environment.
4. Designing Safer ChemicalsChemical products should be designed to effect their desired function while minimisingtheir toxicity.
5. Safer Solvents and AuxiliariesThe use of auxiliary substances (e.g., solvents or separation agents) should be madeunnecessary whenever possible and innocuous when used.
6. Design for Energy EfficiencyEnergy requirements of chemical processes should be recognised for their environmentaland economic impacts and should be minimised. If possible, synthetic methods should beconducted at ambient temperature and pressure.
The 12 Principles of Green Chemistry (1-6)
7 Use of Renewable FeedstocksA raw material or feedstock should be renewable rather than depleting whenever technically and
economically practicable.
8 Reduce DerivativesUnnecessary 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 CatalysisCatalytic reagents (as selective as possible) are superior to stoichiometric reagents.
10 Design for DegradationChemical 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 PreventionAnalytical 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 PreventionSubstances 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.
The 12 Principles of Green Chemistry (7-12)
E-factor
API Manufacturing Issues
• Batch-based processes
• Multi-step synthesis, transformations –intermediates
• Isolations (purification)
• Extensive use of multiple organic solvents and reagents – varying degrees of toxicity
• Limited health data on intermediates
API Manufacturing Issues
• Processes – solid/liquid – filtration, drying, etc
• Purity and yield
• 7-11 years between development and manufacture – Regulatory steps (Phase I-III)
• 10% success rate for new drug development
• Outsourcing process steps
• Once process is approved by regulators, any changes are hard to implement
Atom EconomyOrganic Chemistry & Percent Yield
Epoxidation of an alkene using a peroxyacid
O O
OH
Cl
+
O
100% yield
Percent yield:Percent yield:
% yield = (actual yield/theoretical yield) x 100
What is missing?
What co-products are made?
How much waste is generated?
Is the waste benign waste?
Are the co-products benign and/or useable?How much energy is required?
Are purification steps needed?
What solvents are used? (are they benign and/or reusable?
Is the “catalyst” truly a catalyst? (stoichiometric vs. catalytic?)
Balanced Reaction
Balanced chemical reaction of the epoxidation of styrene
O O
OH
Cl
+
O
+
O OH
Cl
Atom Economy
Atom Economy
% AE = (FW of atoms utilized/FW of all reactants) X 100
Balanced Equations
Focuses on the reagents
Stoichiometry?
How efficient is the reaction in practice?
Solvents?
Energy?
Atom Economy
Balanced chemical reaction of the epoxidation of styrene
O O
OH
Cl
+
O
+
O OH
Cl
Assume 100% yield.
100% of the desired epoxide product is recovered.
100% formation of the co-product: m-chlorobenzoic acid
A.E. of this reaction is 23%.
77% of the products are waste.
Classic Route to Ibuprofen
Ac2O
AlCl3
CO CH3
HCl, AcOH, Al W aste
ClCH2CO
2Et
NaOEt
OEtO
2C
HCl
H2O / H+
O HC
AcOH
NH2OH
O HNN
H2O / H+
HO2C
NH3
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100
= (206/514.5) X 100 = 40%
Hoechst Route To Ibuprofen
O
HF
AcOH
Ac2O
H2 / Ni
OH
CO, Pd
HO2C
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100
= (206/266) X 100 = 77%
Oxidation : Atom Economy
Of various oxidants
Less Hazardous Chemical Synthesis
Disadvantages
phosgene is highly toxic, corrosive
requires large amount of CH2Cl2
polycarbonate contaminated with Cl impurities
OH OHCl Cl
O
+NaOH
O O *
O
* n
Whenever practicable, synthetic methodologies should be designed
to use and generate substances that possess little or no toxicity to
human health and the environment.
e.g. Polycarbonate Synthesis: Phosgene Process
Designing Safer Chemicals:
Case Study: Antifoulants
Antifoulants are generally dispersed in the paint as it is
applied to the hull. Organotin compounds have traditionally
been used, particularly tributyltin oxide (TBTO). TBTO
works by gradually leaching from the hull killing the
fouling organisms in the surrounding area
TBTO and other organotin antifoulants have long half-lives
in the environment (half-life of TBTO in seawater is > 6
months). They also bioconcentrate in marine organisms (the
concentration of TBTO in marine organisms to be 104 times
greater than in the surrounding water).
Organotin compounds are chronically toxic to marine life
and can enter food chain. They are bioaccumulative.
Designing Safer Chemicals:
Case Study: Antifoulants
Sea-Nine® 211
http://www.rohmhaas.com/seanine/index.html
Rohm and Haas
Presidential Green Chemistry Challenge Award, 1996
The active ingredient in Sea-Nine® 211, 4,5-dichloro-2-n-octyl-4-
isothiazolin-3-one (DCOI), is a member of the isothiazolone family
of antifoulants.
5. Safer Solvents and
Auxiliaries
The use of auxiliary substances (solvents,
separation agents, etc.) should be made
unnecessary whenever possible and, when
used, innocuous.
Safer Solvents
• Solvent Substitution
• Water as a solvent
• New solvents
– Ionic liquids
– Supercritical fluids
Preferred Useable Undesirable
Water Cyclohexane Pentane
Acetone Heptane Hexane(s)
Ethanol Toluene Di-isopropyl ether
2-Propanol Methylcyclohexane Diethyl ether
1-Propanol Methyl t-butyl ether Dichloromethane
Ethyl acetate Isooctane Dichloroethane
Isopropyl acetate Acetonitrile Chloroform
Methanol 2-MethylTHF Dimethyl formamide
Methyl ethyl ketone Tetrahydrofuran N-Methylpyrrolidinone
1-Butanol Xylenes Pyridine
t-Butanol Dimethyl sulfoxide Dimethyl acetate
Acetic acid Dioxane
Ethylene glycol Dimethoxyethane
Benzene
Carbon tetrachloride
“Green chemistry tools to influence a medicinal chemistry and research chemistry based organization”
Dunn and Perry, et. al., Green Chem., 2008, 10, 31-36
Solvent Selection
Red Solvent Flash point (°C) Reason
Pentane -49 Very low flash point, good alternative available.
Hexane(s) -23 More toxic than the alternative heptane, classified as a HAP in the US.
Di-isopropyl ether -12 Very powerful peroxide former, good alternative ethers available.
Diethyl ether -40 Very low flash point, good alternative ethers available.
Dichloromethane n/a High volume use, regulated by EU solvent directive, classified as HAP in US.
Dichloroethane 15 Carcinogen, classified as a HAP in the US.
Chloroform n/a Carcinogen, classified as a HAP in the US.
Dimethyl formamide 57 Toxicity, strongly regulated by EU Solvent Directive, classified as HAP in the US.
N-Methylpyrrolidinone 86 Toxicity, strongly regulated by EU Solvent Directive.
Pyridine 20 Carcinogenic/mutagenic/reprotoxic (CMR) category 3 carcinogen, toxicity, very low threshold limit value (TLV) for worker exposures.
Dimethyl acetate 70 Toxicity, strongly regulated by EU Solvent Directive.
Dioxane 12 CMR category 3 carcinogen, classified as HAP in US.
Dimethoxyethane 0 CMR category 2 carcinogen, toxicity.
Benzene -11 Avoid use: CMR category 1 carcinogen, toxic to humans and environment, very low TLV (0.5 ppm), strongly regulated in EU and the US (HAP).
Carbon tetrachloride n/a Avoid use: CMR category 3 carcinogen, toxic, ozone depletor, banned under the Montreal protocol, not available for large-scale use, strongly regulated in the EU and the US (HAP).
“Green chemistry tools to influence a medicinal chemistry and research chemistry based organization”
Dunn and Perry, et. al., Green Chem., 2008, 10, 31-36
Undesirable Solvent Alternative
Pentane Heptane
Hexane(s) Heptane
Di-isopropyl ether or diethyl ether 2-MeTHF or tert-butyl methyl ether
Dioxane or dimethoxyethane 2-MeTHF or tert-butyl methyl ether
Chloroform, dichloroethane or carbon
tetrachloride
Dichloromethane
Dimethyl formamide, dimethyl
acetamide or N-methylpyrrolidinone
Acetonitrile
Pyridine Et3N (if pyridine is used as a base)
Dichloromethane (extractions) EtOAc, MTBE, toluene, 2-MeTHF
Dichloromethane (chromatography) EtOAc/heptane
Benzene Toluene
Solvent replacement table
“Green chemistry tools to influence a medicinal chemistry and research chemistry based organization”
Dunn and Perry, et. al., Green Chem., 2008, 10, 31-36
List of solvents and
thier limits
Safer solvents: Supercritical fluids
A SCF is defined as a substance above its critical temperature (TC) and critical pressure (PC). The critical
point represents the highest temperature and pressure at which the substance can exist as a vapor and
liquid in equilibrium.
Principle 5: Benign solvents
Carbon-carbon bond formation in water
Diels-Alder, Barbier-Grignard, pericyclic
Indium-mediated cyclopentanoid formation
Li, Tulane University
R2
O O Cl Cl
base
O
R2
O
Cl
R1
R1
In/H2O
OH
R2
OR1
7. Use of Renewable Feedstock
A raw material or feedstock should be
renewable rather than depleting whenever
technically and economically practical.
Petroleum Products [Hydrocarbons]
Biomaterials [Carbohydrates, Proteins, Lipids]
Highly Functionalized Molecules
Singly Functionalized Compounds [Olefins, Alkylchlorides]
Highly Functionalized Molecules
Polymers from Renewable Resources:
Polyhydroxyalkanoates (PHAs)• Fermentation of glucose in the presence of bacteria and propanoic acid (product
contains 5-20% polyhydroxyvalerate)
• Similar to polypropene and polyethene
• Biodegradable (credit card)
O
HO
OH
OH
OH
OH
Alcaligenes eutrophus
propanoic acid
R
O
O
R = Me, polydroxybutyrate
R = Et, polyhydroxyvalerate
n
Polymers from Renewable Resources:
Poly(lactic acid)
Raw Materials from Renewable Resources:
The BioFine Process
O
HO
O
Paper mill
sludge
Levulinic acid
Municipal solid waste
and waste paper
Agricultural
residues,
Waste wood
Green Chemistry Challenge Award
1999 Small Business Award
Levulinic acid as a platform chemical
O
HO
O
O
H2N
OH
O
O
HO
DALA (-amino levulinic acid)
(non-toxic, biodegradable herbicide)
O
HO
O
OH
C
CH3
CH2
CH2
C
O
OHHO
Diphenolic acid
Acrylic acidSuccinic acid
O
THF
O
MTHF
(fuel additive)
HO
OH
butanediol
OO
gamma
butyrolactone
8. Reduce Derivatives
Unnecessary derivatization (blocking
group, protection/deprotection, temporary
modification of physical/chemical
processes) should be avoided whenever
possible.
Protecting Groups
2 synthetic steps are added each time one
is used
Overall yield and atom economy will
decrease
“Protecting groups are used because
there is no direct way to solve the
problem without them.”
9. Catalysis
Catalytic reagents (as selective as
possible) are superior to stoichiometric
reagents.
Heterogeneous vs Homogenous
• Distinct solid phase
• Readily separated
• Readily regenerated & recycled
• Rates not as fast
• Diffusion limited
• Sensitive to poisons
• Lower selectivity
• Long service life
• High energy process
• Poor mechanistic understanding
• Same phase as rxn medium
• Difficult to separate
• Expensive and/or difficult to
separate
• Very high rates
• Not diffusion controlled
• Robust to poisons
• High selectivity
• Short service life
• Mild conditions
• Mechanisms well understood
Heterogeneous vs Homogenous
• Distinct solid phase
• Readily separated
• Readily regenerated &
recycled
• Rates not as fast
• Diffusion limited
• Sensitive to poisons
• Lower selectivity
• Long service life
• High energy process
• Poor mechanistic understanding
• Same phase as rxn medium
• Difficult to separate
• Expensive and/or difficult to
separate
• Very high rates
• Not diffusion controlled
• Robust to poisons
• High selectivity
• Short service life
• Mild conditions
• Mechanisms well understood
Green
catalyst
Principle 9: Catalysis
Improved synthesis of a central nervous system compound
interdisciplinary approach, combining chemistry,
microbiology, and engineering
For every 100 kg product,
300 kg chromium waste eliminated
34,000 liters solvent eliminated
Eli Lilly and Company
Principle 9: Catalysis
Synthesis of disodium iminodiacetate (DSIDA)
filter catalyst from waste stream, no additional
purification required
Replacement for the Strecker process
utilized NH3, CH2O, HCN, HCl
Monsanto Company
NOH OH
H
Cu catalyst NNaO ONa
O OH
DSIDA
+ 2 NaOHH2O /
+ 4 H2
Biocatalysis• Enzymes or whole-cell
microorganisms
• Benefits
– Fast rxns due to correct orientations
– Orientation of site gives high
stereospecificity
– Substrate specificity
– Water soluble
– Naturally occurring
– Moderate conditions
– Possibility for tandem rxns (one-
pot)
Kinetic resolution of a racemic mixture
Kinetic resolution of a racemic mixture
the presence of a chiral object (the enzyme) converts one of the enantiomers into product at a greater reaction rate than the other enantiomer.
10. Design for Degradation
Chemical products should be
designed so that at the end of
their function they do not persist
in the environment and instead
break down into innocuous
degradation products.
Persistence• Early examples:
• Sulfonated detergents
– Alkylbenzene sulfonates – 1950’s & 60’s
– Foam in sewage plants, rivers and streams
– Persistence was due to long alkyl chain
– Introduction of alkene group into the chain increased
degradation
• Chlorofluorocarbons (CFCs)
– Do not break down, persist in atmosphere and
contribute to destruction of ozone layer
• DDT
– Bioaccumulate and cause thinning of egg shells
Degradation of Polymers:Polylactic Acid
Manufactured from renewable resources
Corn or wheat; agricultural waste in
future
Uses 20-50% fewer fossil fuels than
conventional plastics
PLA products can be recycled or
composted
Cargill Dow
12. Inherently Safer Chemistry for
Accident Prevention
Substance and the form of a substance
used in a chemical process should be
chosen so as to minimize the potential for
chemical accidents, including releases,
explosions, and fires. : Avoid Phosgene
Cyanide
Design Safer Chemicals
• Water-based acrylic alkyd paints with low VOCs that can be
made from recycled soda bottle plastic (PET), acrylics, and
soybean oil. In 2010, Sherwin-Williams manufactured
enough of these new paints to eliminate over 800,000
pounds of VOCs.
• Foam cushioning are conventionally manufactured from
petroleum products. Cargill’s BiOH™ polyols are
manufactured from renewable, biological sources such as
vegetable oils. Each million pounds of BiOH™ polyols
saves nearly 700,000 pounds of crude oil. Cargill’s process
reduces total energy use by 23 percent and carbon dioxide
emissions by 36 percent.
51
Phenolic ethers, Pharmaceuticals,
Flavours and Fragrances Quaternarium ammoniumcompounds
Surfactants, Softeners, Electronics
Diphenyl carbonate
Aromatic polycarbonates
Methylisocianate production
Allylcarbonates
Optical organic glassesAliphatic polycarbonate diols
Polyuretans
Oxoalcohol carbonates
Synthetic lubricants
Dialkyl Carbonates
Green solvents
Paints, adhesives
Policarbonate 53 %
Coatings and paintings 28%
Agrochemicals 12%
Pharm. &
Cosmetics 5%
Electrolite
solv.2%
Design Safer Chemicals
Dimethyl Carbonate Tree and Its Industrial
Uses
F. Aricò,M. Chiurato, J. Peltier and Pietro Tundo Eur. J. Org. Chem. 2012, 3223–3228
US EPA Presidential Green Chemistry Award
Promotes and recognizes green chemistry
Five Categories
1. Alternative synthetic pathways
2. Alternative reaction conditions
3. Design of safer chemicals
4. Small business
5. Academic investigator
Source: http://www.epa.gov/greenchemistry
“Alternative synthetic pathways Award”
• 1999 Lilly Research Laboratories (Talampanel)
• 2000 Roche Colorado Corp (Cymevene®)
• 2002 Pfizer, Inc (Zoloft®)
• 2004 Bristol-Meyers Squibb Company (Taxol)
• 2005 Merck & Co. Inc. (Emend®)
• 2006 Merck & Co. Inc. (Januvia®)
• 2006 Codexis, Inc. for Atorvastatin (Lipitor®)
• 2010 Merck & Co. Inc. and Codexis, Inc. (Januvia™ II generation)
54
Presidential Green Chemistry
Challenge Award
• Established in 1995 by the EPA
• For innovations in cleaner, cheaper and smarter chemistry
www.epa.gov/greenchemistry/presgcc.html
http://pubs.acs.org/cen/coverstory/8026/8026greenchemistry.html
HN
N
O
H2N
N
N
OOH
HO
Cytovene®2000 Roche Corp.
Reduced liquid waste: 1120 metric tons / yearReduced solid waste: 25 metric tons / year
HN
Cl
Cl
HCl
Zoloft®
2002 Pfizer, Inc.
Reduced waste:
HCl (conc): 150 metric tons / year
TiO2: 440 metric tons / year
HN
HN N
O
N
O O
F
CF3
CF3
Emend®2005 Merck
Reduced waste:340,000 L / metric ton
55
Emend® - Aprepitant
• hNK1 receptor antagonist (IC50 = 0.09 nM)1
• Treatment of chemotherapy-induced emesis2
• FDA approval in 2003
• 2005 Presidential Green Chemistry Challenge Award3
• Entered preclinical trials in 19931
1 Hale, J. J. et al; J. Med. Chem. 1998, 41, 4607-4614. 2 Rupniak, N. M. et al; Eur. J. Pharmacol. 1997, 326, 201-209.3 http://www.epa.gov/greenchemistry/past.html
HN
NH
N
O
CF3
CF3
O
N
O
F
2
3
56
General Considerations for Process Chemistry
• Avoid column chromatography
• Seeding helps crystallization
• Avoid desiccants, use azeotrope
• Avoid solvents with flash point < 15 ºC
• Ether, hexanes, DCM
• Temperature range -40 to 120 ºC
• Avoid protecting groups
• Impurities of > 0.1% must be analyzed
57
Presidential Green Chemistry Challenge
Award – 2005:Emend synthesis
• Convergent synthesis
– Overall yield 55% (6 steps)
– Uses 20% of raw materials as
original synthesis
– Reduce waste by 85%
• 340,000L / metric ton aprepitant
http://www.epa.gov/greenchemistry/past.html
C&E News June 27, 2005 pg 40-43
N
O OH
O
Ph
CF3
CF3
OH
HN
NH
N
O
F
BrMg
CF3
CF3
O
N
O
F
HN
NH
N
O
Cl
Green Chemistry Example – Bristol-
Myers Squibb Taxol®
• Development of a green synthesis for Taxol®
manufacture via plant cell fermentation and
extraction
• Paclitaxel, the active ingredient in the anticancer
drug Taxol® originally isolated from yew tree
bark
2004 Presidential Green Chemistry Challenge
Alternative Synthetic Pathways Award
www.epa.gov/greenchemistry/aspa04.html
• Natural purification from yew tree bark
- 0.0004% paclitaxel
- Stripping bark and extraction process kills tree – not sustainable
- Yews take 200 yrs to mature – ecosystem impact
• Chemical synthesis of paclitaxel
- 40 steps, 2% yield
• Semisynthetic route from naturally occurring yew-based 10-deacetylbaccatin III
- 11 chemical transformations, 7 isolations
- 13 solvents
- 13 reagents, catalysts, etc
www.epa.gov/greenchemistry/aspa04.html
Pfizer’s results
Use of Solvent Replacement Guide resulted in:
• 50% reduction in chlorinated solvent use across the whole
of their research division (more than 1600 lab based
synthetic organic chemists, and four scale-up facilities)
during 2004-2006.
• Reduction in the use of an undesirable ether by 97% over
the same two year period
• Heptane used over hexane (more toxic) and pentane (much
more flammable)
“Green chemistry tools to influence a medicinal chemistry and research chemistry based organization”
Dunn and Perry, et. al., Green Chem., 2008, 10, 31-36
First preparative route to
sildenafil citrate.
Convergent commercial
preparation of sildenafil citrate
Redesign of the Sertraline Process
Sertraline: active ingredient in Zoloft
Combined process
Doubled yield
Ethanol replaced CH2Cl2, THF, toluene, and
hexane
Eliminated use of 140 metric tons/year TiCl4
Eliminated 150 metric tons/year 35% HCl
Pfizer
Early process synthesis of sertraline
Comparison of routes between the old and new commercial synthesis
of sertraline HCl.
Less Hazardous Chemical Synthesis
Classic batch approach
produces ca 3000 Kg of
waste each Kg of amino
ketone
R1
O
R2
NH2
Synthesis of amino ketones
Automate flow approach using safer
solvent produces only 2.3 Kg of waste
each Kg of amino ketone
> 99.9% reductionAdv. Synth. Catal. 2012, 354, 908–916
Research to Commercialization: Thomas Swan & Co Ltd
Multi-purpose plant using supercritical fluids
First full-scale facility for continuous, multi-purpose
synthesis, including
Hydrogenations
Friedel-Crafts reactions
Hydroformylations
Etherifications
Technology developed with the University of
Nottingham
Reactions in Supercritical Fluids
Formation of cyclic ethers
Hydrogenation
Poliakoff, University of Nottingham
HO OH
acid catalyst
O+ H2O
NO2 NH2Pd or Pt catalyst
propane, 80 bar
150-250 0C
Principle 1: Waste prevention
Cytovene
antiviral agent used in the treatment of cytomegalovirus
(CMV) retinitis infections
AIDS and solid-tissue transplant patients
Improved synthesis
reduced chemical processing steps from 6 to 2
reduced number of reagents and intermediates from 22
to 11
eliminated 1.12 million kg/year liquid waste
eliminated 25,300 kg/year solid waste
increased overall yield by 25%
Alternative Synthetic Pathways
Sodium iminodisuccinate
Biodegradable, environmentally friendly chelating agent
Synthesized in a waste-free process
Eliminates use of hydrogen cyanideBayer Corporation and Bayer AG
2001 Alternative Synthetic Pathways Award Winner
O
O
O
NaOH NH3 ONa
ONaNaO
NaON
H
O O
O O
Principle 4: Reduce Toxicity
Spinosad: a natural product for insect control
produced by Saccharopolyspora spinosa
isolated from Caribbean soil sample
demonstrates high selectivity, low toxicity
Dow AgroSciences
OO
H
O
HH
HH
OMe
OMe
OMe
O
O
OO
R
Me2N
Spinosyn A: R = HSpinosyn D: R = CH3
Small Business Award
PYROCOOL Technologies, Inc.
PYROCOOL F.E.F. (Fire Extinguishing Foam)
0.4% aqueous mixture of highly biodegradable
nonionic surfactants, anionic surfactants, and
amphoteric surfactants
replacement for halon gases and aqueous film
forming foams (AFFFs)
Principle 7: Renewable feedstocks
CO2 feedstock in polycarbonate synthesis
Improved Zn catalyst yields faster reaction, uses
milder reaction conditions
Coates et al., Cornell University
O
+ CO2
500 C, 100 psi CO2
catalyst
O*
O *
O
n
N NZn
OAc
iPr
iPr
Pri
Pri
catalyst =
Boric Acid-Mediated Amidation
Direct amidation of carboxylic acids with amines
Boric acid: nontoxic, safe, inexpensive
Eliminates use of SOCl2, PCl3, phosgene
Widely applicableEmisphere Technologies, Inc
R OH
O
H N
R'
R''R N
O
R'
R''
H2O+cat B(OH)3
toluene
reflux
+
Principle 12: Minimize hazard
Catalytically synthesize methylisocyanate to reduce risk of exposure
– eliminates use of phosgeneManzer, DuPont
Old Synthesis of Methylisocyanate
New Synthesis of Methylisocyanate
CH3NH2 + COCl2 CH3NCO + HCl
CH3NH2 + CO CH3NHCHOcatalyst
CH3NHCHO + O2
catalystCH3NCO
Reactions to be considered
• Green Mitsunobu Reactions
• Reduction of amides avoiding LAH and Diborane
• Bromination Reactions
• Sulfonation reactions
• Amide Formation avoiding poor atom economy reagents
• Nitration reactions
• F/C Reactions on unactivated substrates
• Demethylation Reactions
• Ester Hydrolysis
• OH activation for nucleophillic substitution
• Epoxidation
• Oxidation
• Wittig Chemistry without (Ph3PO)
• Radical Chemistry without Bu3SnH
• Solventless Reactor Cleaning
• Polar Aprotic replacements for NMP, DMSO, DMAc, DMF etc
• Asymmetric Hydrocyanation
• Aldehyde or Ketone + NH3 + “X” to give a chiral amine
• N-Centred chemistry avoiding azides hydrazines etc
• Asymmetric Hydrolysis of nitriles
• Asymmetric Hydrogenation of unfunctionalised olefins/enamines/imines
• Asymmetric Hydroformylation
• C-H activation of aromatics
• C-H activation of alkyl groups
• New Green Fluorination Methods
• Oxygen Nucleophiles with high reactivity
• Green sources of electrophilic Nitrogen
• Asymmetric Hydroamination of olefins
• Asymmetric Hydration of olefins
• Organocatalysis
• ROH + ArCl to give ROAr
Resources
• Green Chemistry in the
Pharmaceutical Industry,
Peter J.
Dunn (Editor), Andrew
Wells (Editor), Michael T.
Williams (Editor), ISBN:
978-3-527-32418-7, 388
pages,March 2010
Resources
• Green Chemistry Articles of Interest to the
Pharmaceutical Industry, Org. Process Res.
Dev., 2013, 17 (11), pp 1394–1405
Area of work
● Catalysis
● Ultrasound and microwave assisted organic reactions and
catalysis.
● Nanomaterials synthesis
● Ionic Liquids
● Catalysis and reactions in supercritical carbon dioxide.
● Carbon dioxide fixation into valuable chemicals
● Carbon monoxide fixation into valuable chemicals
● Enzymatic Catalysis
79
Formal Courses in Green Technology and
Sustainable Development
Degree Courses
Inclusion of Green Chemistry as a subject in all
U.G. courses of ICT – Chemical Engineering,
Chemical Technologies and Pharmaceutical
Sciences
a) M. Tech. Course ( 4 semesters) full time
b) M. Tech. Course (6 semesters ) part time
c) Ph. D. degree ( 3 years )
81
M.Tech. - Green Technology
In view of the global growing demand for specialised workforce in green
chemistry and technology Institute of Chemical Technology has started a
multidisciplinary postgraduate course i.e. Master of Green Technology.
The course is the first of its kind in the country and has been gaining
increasing response from the students and chemical industry.
The first batch of M. Tech. (Green Technology) in 2010 evidenced
enrolment of 14 students followed by enrolment of 27 students for the
second batch in 2011.
Most of these students are pursuing their interest in green chemistry and
technology by joining for Ph.D. course in green technology.
Fresh M. Tech. pass out students from the two batches have also found
good industrial placements with companies like E-value Serve, Loreal etc. to
name a few.
82
An efficient & heterogeneous
recyclable palladium catalyst for chemoselective
conjugate reduction of α,β-unsaturated
carbonyls in aqueous medium
D. B. Bagal, Z. S.
Qureshi K. P.
Dhake, S. R. Khan and
B. M. Bhanage
An highly efficient PS-Pd-NHC catalytic system has been
developed for chemoselective conjugate reduction of α,β-
unsaturated carbonyl compounds providing good to excellent
conversion with remarkable chemoselectivity (up to 100%). The
developed protocol is more advantageous due to use of
HCOONa as hydrogen source, environmentally
benign water assolvent and effective catalyst recyclability.
Green Chem., 2011, 13,
1490–1494
83
Pd/C-Catalyzed Synthesis of Oxamates by Oxidative Cross
Double Carbonylation of Amines and Alcohols under Co-
catalyst, Base, Dehydrating Agent, and Ligand-Free
Conditions
S.T. Gadge and B.M.
Bhanage
This work reports a mild, efficient, and ligand-free Pd/C-
catalyzed protocol for the oxidative cross double carbonylation
of amines and alcohols. Notably, the reaction does not requires
any base, co-catalyst, dehydrating agent, or ligand. Pd/C solves
the problem of catalyst recovery, and the catalyst was recycled
up to six times.
J. Org. Chem., 2013,
78 (13), 6793–6797
84
Shape selectivity using ionic liquids for the preparation of
silver
and silver sulphide nanomaterials
Amol B. Patil and
Bhalchandra.M.
Bhanage
Electrodeposition of silver and silver sulphide was carried out from
two protic ionic liquids. A change of the anion moiety of ionic liquid
was found to bring about significant changes in the morphology of the
nanocrystalline silver and silver sulphide deposits obtained. Effects of
various parameters like deposition overpotential, change of the
substrate, deposition time, etc. on the particle size and shape were
studied. It was found that a change of anions of the ionic liquid from
acetate to nitrate results in a wide difference in the morphology of the
deposits obtained. Acetate containing ionic liquids result in globular
nanocrystalline deposits whereas nitrate containing ionic liquids result
in flat plates or sheets of silver deposits. Similar results were obtained
for silver sulphide nanocrystals.
Phys. Chem. Chem. Phys.,
2014, 16, 3027--3035
85
Oxidative Aminocarbonylation of Terminal Alkynes for the
Synthesis of Alk-2-ynamides by Using Palladium-on-Carbon
as Efficient, Heterogeneous, Phosphine-Free, and Reusable
Catalyst
S.T. Gadge, M. V. Khedkar,
S. R. Lanke, B.M. Bhanage
Palladium-on-carbon (Pd/C)-catalyzed oxidative
aminocarbonylations of alk-1-ynes with secondary amines
provide the corresponding alk-2-ynamides in a good to excellent
yields. This new methodology is applicable for the synthesis of a
wide range of biologically active alk-2-ynamide derivatives. The
developed protocol avoids the use of phosphine ligands, with an
additional advantage of palladium catalyst recovery and reuse for
up to four consecutive cycles.
Advanced Synthesis &
Catalysis Volume
354, Issue 10, pages
2049–2056.
86
Palladium on Carbon: An Efficient, Heterogeneous and
Reusable Catalytic System for Carbonylative Synthesis of N-
Substituted Phthalimides
Mayur V. Khedkar, Shoeb R.
Khan, Dinesh N. Sawant,
Dattatraya B. Bagal,
Bhalchandra M. Bhanage
The application of palladium on carbon (Pd/C) as a heterogeneous
recyclable catalyst was investigated for the double carbonylation of o-
dihaloarenes with amines providing excellent yield of N-substituted
phthalimides in shorter reaction time as compared to earlier reported
homogeneous protocols. Furthermore, the scope of the developed
protocol was applied for the synthesis N-substituted phthalimides
fromo-halobenzoates and o-halobenzoic acid via a single step
carbonylative cyclization reaction. The developed methodology
describes an efficient one-step approach for the synthesis of an
important class of heterocycles and tolerates a wide variety of
functional groups. It circumvents the use of phosphine ligands with an
additional advantage of catalyst recyclability for up to eight
consecutive cycles.
Advanced Synthesis &
Catalysis Volume 353, Issue
18, 3415–3422,
87
Amine functionalized MCM-41: an efficient heterogeneous recyclable
catalyst for the synthesis of quinazoline-2,4(1H,3H)-diones from
carbon dioxide and 2-aminobenzonitriles in water
Deepak B. Nale
Surjyakanta Rana
Kulamani Parida,
Bhalchandra M. Bhanage
A simple covalently linked amine functionalized MCM-41 were
investigated as a highly efficient, heterogeneous and recyclable
mesoporous catalytic protocol for the synthesis of a wide variety of
quinazoline-2,4(1H,3H)-diones derivatives from 2-aminobenzonitriles and
carbon dioxide in aqueous reaction medium. This catalytic system
represents a heterogeneous and environmentally benign protocol. The
effect of various reaction parameters, such as influences of solvent,
temperature, CO2 pressure and time for the synthesis of quinazoline-
2,4(1H,3H)-diones were studied. The developed protocol can be applicable
for the synthesis of most important key intermediate 6,7-
dimethoxyquinazoline-2,4(1H,3H)-dione and several biologically active
derivatives such as Prazosin, Bunazosin and Doxazosin. Besides this, the
developed catalyst could be reused for five consecutive recycles without
any significant loss in its catalytic activity.
Catal. Sci. Technol., 2014,
DOI: 10.1039/C3CY00992K
88
Asymmetric Ring Opening of meso-Epoxides with Aromatic
Amines Using (R)-(+)-BINOL-Sc(OTf)3-NMM Complex as
an Efficient Catalyst
Ganesh V. More, Bhalchandra
M. Bhanage
European Journal of Organic
Chemistry 2013,30, pages
6900–6906
This work reports the asymmetric ring-opening reaction
of meso-epoxides with aromatic amines by using the highly
efficient in situ generated (R)-(+)-BINOL-Sc(OTf)3-N-
methylmorpholine complex. The asymmetric ring opening
of cis-stilbene oxide with various substituted aromatic amines
gave enantioenriched β-amino alcohols in good yields and with
excellent enantioselectivities when the reaction was conducted
at 0 °C for 12 h. The reaction proceeded under mild conditions
using simple and inexpensive starting materials such as (R)-(+)-
1,1′-bi-2-naphthol [(R)-(+)-BINOL], meso-stilbene oxide,
aniline derivatives, and 4 Å molecular sieves.
Ultrasound Assisted Regioselective Nitration
of Phenol using Dilute Nitric Acid in a
Biphasic Medium: Case study
A. Vogel, Fourth ed., Longman, London, 1978.
59% 41%
OH OH
NO2
HNO3
H2SO
4
OH
NO2
+
Prior Art
Acid Anhydrides
Metal Nitrates
N2O5
Solid Acid Catalysts (Cat Commun.2002, 3, 67.)
Surfactant (Tetrahedron 1988, 44, 4555.)
Ionic Liquids (J.O.C. 2001, 66, 35)
Microwave(Abstr.Papers.Am.Chem.Soc.1999,217,224-ENVR,Part I)
Ultrasound (Ulrason. Sonochem. 2007, 14, 41-45.)
Disadvantages
Lower Yield & Selectivity
Longer Reaction Time
Expensive Reagents
Sophisticated Techniques
Environmentally Hazardous
Ultrasound is widely used for improving the
traditional reactions that use expensive reagents,
strongly acidic conditions, long reaction times,
high temperatures, unsatisfactory yields and
incompatibility with other functional groups
Introduction
Nitration using PTC under sonication
OH
R
OH
NO2
R
OH
NO2
R
++ 6wt% HNO3
))), 25 oC
PTC
Ultrasound promoted regioselective nitration of phenols using dilute
nitric acid in the presence of phase transfer catalyst.
N.S.Nandurkar, M.J.Bhanushali, S.R.Jagtap and B.M.Bhanage
Ulrason. Sonochem. 2007, 14, 41-45.
Indian Patent No. IN 241202, (2010).
Regioselective nitration of phenol
R
OH
R
OH
R
OH
NO2
NO2
+)))))
9wt%HNO3
Improved Process for nitration of phenol using diluted nitric acid alone as the
nitrating agent under sonication.
N. S. Nandurkar, M. J. Bhanushali, A.G. Panda, B. M. Bhanage
Indian Patent No. IN 247957, (20011)
No Substrate Condition Time Conversion
(%)
Selectivity
p-nito o-nito
1 Phenol Silent 46 h 30 49 48
3 Phenol ((((( 2 h 94 70 27
3 o-cresol Silent 48 h 29 50 48
4 o-cresol ((((( 2 h 90 67 29
5 m-cresol Silent 48 h 25 50 47
6 m-cresol ((((( 2 h 85 63 34
7 p-cresol Silent 48 h 27 - 85
8 p-cresol ((((( 2 h 100 - 96
9 o-chlorophenol Silent 48 h 22 49 48
10 o-chlorophenol ((((( 2 h 83 60 36
11 p-chlorophenol Silent 48 h 20 - 87
12 p-chlorophenol ((((( 2 h 80 - 94
Table 7. Nitration of phenols and substituted phenols
using dilute nitric acid.
Substrate (5 mmol); nitric acid (70 wt%, 10 mmol) calculated amount of water to make 9 wt%
nitric acid (wt/wt); 1,2-dichloroethane (10 ml); agitation speed 200 rpm; temp 28-30 0C.
Our advantages over the conventional nitration
procedures
Higher yield and selectivity
Significant enhancement in reaction rate
Use of dilute Nitric acid (9 wt%)
No additives
Compatibility with various functional groups
No side reactions
9797
Sulfonation under sonication: No
need of oleum
H2SO4
SO3H
)))))
25-30oC
+
Conc.R R
Z. S. Qureshi, B. M. Bhanage, Ultrasonics Sonochemistry, 2009, 16, 308-311
Indian Patent IN 247765
Thank you……