Photo fries rearrangement

Photo fries rearrangement

• 1.
  PHOTO-FRIES REARRANGEMENT PHOTO-FRIES REACTIONSOF ANILIDES Guided By Presented By Mr.Nasir Ahmed Sumeet Kumar Jha Dr.Ashish Asatkar M.Sc.(Chemistry) Mrs.Chitra Kiran Patel 3rd Semester GOVT.GUNDADHUR P.G.COLLEGE,KONDAGAON(C.G.)
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  CONTENTS FRIES REACTION  THEORY REACTION PHOTO-FRIES REARRAGEMENT  THEORY  REACTION  MECHANISM PHOTO-FRIES REACTION OF ANILIDES REFFERENCE
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  FRIES REACTION Conversion ofphenolic ester in to hydroxy aryl ketones in presence of catalyst called Fries Reaction.
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  PHOTO-FRIES REARRANGMENT Conversion ofphenolic ester in to hydroxy aryl ketones in presence of UV-light without catalyst called Photo-Fries Rearrangment. Photo-Fries rearrangment is an intramolecular rearrangment.  Where acyl and alkyl groups migrate to ortho and para position on irradiation.
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   In thisrearrangment the substrate dissociate into phenoxy and acyl radicals.  which combine with in the solvent cage to give intermediates on aromatisation of the product. MECHANISM:-
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  NOTE:- *Photo-Fries rearrangmentis carried out in gaseous phase only phenol is obtained.it confirms that the formation of solvent cage. *It has been seen that when the tempreture of the reaction will be high the ortho product formed and when the tempreture of the reaction is low the para product formed.
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  OTHER EXAMPLES:- The followingcompounds give similar type of reaction-mechanism:
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  PHOTO-FRIES REACTIONS OFANILIDES  Photo-Fries rearrangment of anilides obey the same mechanism as Photo-Fries rearrangment of phenyl esters.  The only difference is the replacement of bridging oxygen by nitrogen.
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  REFERENCE Textbook of ʺPhotochemistryʺby Alka L.Gupta