Organic Chemistry & Unit Processes Vivek TomarPintu Nanera Batch 1D05

Alkylation & Acylation

Outline o Introduction  History  Synthesis  Effect factor o Improve the Friedel – Crafts Reaction  Change catalyst  Change Solvent o Applications Of Friedel – Crafts Reaction  Poly(ether ketone)  Dye o Conclusions

Charles Friedel James Mason Crafts (March 8, 1839 – June 20, 1917) (12 March 1832 – 20 April 1899) French chemist and mineralogist American chemist Charles Friedel And James Mason Crafts In 1877 To Attach Substituents To An Aromatic Ring HISTORY

The Acylation Reaction

The Alkylation Reaction

Effect Factor Catalyst Temperature Aromatic structureSolvent

o The aromatic ring with electron donating groups is facilitate the reaction. Aromatic Structure o Friedel - Crafts reaction temperature is generally less than 90 ~ 100 ℃. o Temperature control can effectively reduce the side reaction. o High activity catalyst reactants still require the high temperature. Temperature

Solvent Most common polar solvent PhNO 2 (acyl) CH 3 NO 2 (alkylation) CH 3 CH 2 NO 2 o CH 3 NO 2, PhNO 2,CS 2 are the best reaction solvent, but because the high toxicity should be avoided. o 1,2 - dichloroethane and methylene chloride is also a good solvent. Most common non-polar solvent CS 2 CCl 4

Lewis acid Catalyst The amount of catalyst: o Activity of the structure o Aromatics, Acylation Reagents o Reaction temperature Brønsted acids o Large amount of catalyst can not be recycled o Must be used under anhydrous conditions o Equipment corrosion o Environmental pollution

Friedel – Crafts Reaction Advantages Simple operation High efficiency and yield Disadvantages Large amount of catalyst can not be recycled Equipment corrosion Environmental pollution  To maintain selectivity, a long reaction time (hours) at a low temperature is necessary.  The use of traditional liquid acid or Lewis acid catalysts and organic solvents cause many problems in cost, apparatus and environment.  After the reaction, the catalyst and the solvent have to be separated from the reaction mixture and either purified for recycling or disposed of.

Improve The Friedel – Crafts Reaction

Change Catalyst

Change Solvent

Applications Of Friedel – Crafts Reaction

Poly(Ether Ketone)

Excellent wear resistance at high temperatures. Excellent hydrolysis resistance at high temperatures. High temperature performance for all mechanical properties. Excellent electrical performance at high temperatures. Excellent chemical resistance at high temperatures. Advantages

Poly(Phenylene Sulfide)

Excellent chemical resistance High temperature performance High modulus when reinforced Advantages

Dyes pH indicator

Biological dye

Food Coloring

Conclusion

o Simple operation o Used in many Organic Syntheses o High efficiency and yield Future work o Green chemistry  Catalyst  Solvent o Equipment corrosion o Environmental pollution Major Advantages

Bibliography A Textbook Of Organic Chemistry, Arun Bahl & B.S. Bahl Advanced Organic Chemistry, Jerry March Wikipedia