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Unformatted text preview: Solvent-Free Synthesis of Solvent Free Chalcones Chalcones
Aldol Condensation Reaction
O O + R1 H O R2 substituted acetophenone NaOH R1 R2 substituted benzaldehyde 3-phenyl-1-phenyl-2-propen-1-one CHALCONE General reaction General Solvent-free “GREEN CHEMISTRY” Solvent Recrystallize product Recrystallize NMR confirmation of trans double bond and product NMR (E)-3-(4-chlorophenyl-1-(4-methoxyphenyl)-2-propen-1-one
O Cl H + O O OCH3 NaOH Cl Chalcone (1) OCH3 Our Synthesis Our Grind all three solids in CLEAN mortar and pestle Grind Heat of reaction liquid product solid Heat liquid product Wash with DI water WELL Wash Filter (Crude: TLC and 1H NMR) Filter (Crude: Recrystallize from ethanol Recrystallize Filter (Pure: TLC and 1H NMR) Filter (Pure: What is Green Chemistry? What
When the EPA began its research grant When program in 1991, it defined green chemistry as.. “Innovative Chemical Technologies that Innovative reduce or eliminate the use or generation of hazardous substances in the design, manufacture and use chemical products” chemical What is Green Chemistry? What
Use chemistry to PREVENT pollution Use Design processes that lower or eliminate Design the use of hazardous chemicals Meet current needs for chemical products Meet without jeopardizing future needs Focus on renewable resources (raw Focus materials from plants, other sources besides petroleum) 12 Principles of Green Chemistry 12
2. 3. 4. 5. 6. 7. 8. 8. 9. 10. 11. 12. Prevention waste (rather than treat) Prevention Atom Economy (max atoms used for product) Less Hazardous Chemical Syntheses Designing Safer Chemicals Safer Solvents and Auxiliaries (separations) Design for Energy Efficiency (rt and atm pressure) and atm Use of Renewable raw materierals and feedstocks Use materierals and feedstocks Reduce Derivatives (protecting groups) Reduce Use Catalytic reagents when possible Design for Degradation in the environment Real-time Analysis for Pollution Prevention Inherently Safer Chemistry for Accident Prevention http://www.epa.gov/greenchemistry/past.html http:// 2006 Award Recipients Greener Synthetic Pathways Award Greener Merck & Co., Inc. Novel Green Synthesis for β-Amino Acids Novel Amino Produces the Active Ingredient in Januvia™ (summary) Januvia Drug for type 2 diabetes Drug Greener Reaction Conditions Award Greener Codexis, Inc Directed Evolution of Three Biocatalysts to Directed Produce the Key Chiral Building Block for Chiral Building Atorvastatin, the Active Ingredient in Atorvastatin the Lipitor® (summary) Lipitor Designing Greener Chemicals Award Designing S.C. Johnson & Son, Inc. Greenlist™ Process to Reformulate Process Consumer Products (summary) Consumer Small Business Award Small Arkon Consultants NuPro Technologies, Inc. Technologies, Environmentally Safe Solvents and Reclamation in the Flexographic Printing Flexographic Printing Industry (summary) Industry Academic Award Academic Professor Galen J. Suppes Professor Suppes University of Missouri-Columbia Biobased Propylene Glycol and Monomers Propylene from Natural Glycerin (summary) from Atom Economy Atom
The atom economy for a reaction can be The calculated using the following equation:
Percent atom economy = Molecular weight of desired product Molecular weights of all reactants x 100% Do for our reaction to go to chalcone Do (only). Include NaOH Mechanism of reaction Mechanism Aldol Reaction to Chalcone Aldol Intermediate Ketol Intermediate Formation of Michael Product Formation 1H NMR Crude
Ha O Cl Chalcone (1) OCH3 Cl Hb OH O O Cl Ketol OCH3 H3CO Hc Hc Hc Hc Michael OCH3 O USEFUL DATA FOR CHALCONE NMR INTERPRETATIONS
Table of Key Chemical Shifts for Chalcone 1, Ketol, and Michael Products
Cl Ha O Hb Hc OH He He O Hd O Hd OCH3 H3CO Hf Hf Hf Hf Michael OCH3 O Cl Hb Chalcone 1 OCH3 Cl Ketol Products of Chalcone Synthesis Chalcone Hx Ha Hb Chemical Shift 7.75 ppm 8.03 ppm 5.30 ppm 7.93 ppm 3.3 ppm 3.3 ppm Splitting Pattern doublet doublet Broad singlet doublet multiplet doublet of doublets #H’s 1 2 1 2 2 4 Ketol Hc Hd He Michael Product Hf 1H NMR Pure – Expanded in Manual NMR 6 sets of “doublets” – 12 peaks in aromatic but sets see 11 due to overlap of one set Trans double bond – Large J value Trans double Para – substituted J value Para Chemical shifts Chemical
O Cl Chalcone (1) OCH3 Expanded Aromatic Region Expanded Starting Materials Starting
O H H3C O Cl OCH3 TLC Analysis TLC p-methoxyacetophenone recrystallized p-chlorobenzaldehyde crude ...
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