Photo fries rearrangement

Photo-Fries Rearrangment And Photo-Fries Reaction Of Anillides

1. PHOTO-FRIES REARRANGEMENT PHOTO-FRIES REACTIONS OF ANILIDES Guided By Presented By Mr.Nasir Ahmed Sumeet Kumar Jha Dr.Ashish Asatkar M.Sc.(Chemistry) Mrs.Chitra Kiran Patel 3 rd Semester GOVT.GUNDADHUR P.G.COLLEGE,KONDAGAON(C.G.)

2. CONTENTS FRIES REACTION THEORY REACTION PHOTO-FRIES REARRAGEMENT THEORY REACTION MECHANISM PHOTO-FRIES REACTION OF ANILIDES REFFERENCE

3. FRIES REACTION Conversion of phenolic ester in to hydroxy aryl ketones in presence of catalyst called Fries Reaction .

4. PHOTO-FRIES REARRANGMENT Conversion of phenolic 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 .

5. In this rearrangment the substrate dissociate into phenoxy and acyl radicals . which combine with in the solvent cage to give intermediates on aromatisation of the product. MECHANISM:-

6. NOTE:- * Photo-Fries rearrangment is 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.

7. OTHER EXAMPLES:- The following compounds give similar type of reaction-mechanism:

8. PHOTO-FRIES REACTIONS OF ANILIDES 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 .

9. REFERENCE Textbook of ʺPhotochemistryʺ by Alka L.Gupta