Application of the Photo‐Fries Reaction as a Key Step in the Preparation of Valuable Aryloxyethyl Selenocyanates

Abstract

AbstractA multistep sequence leads to the preparation of a series of aryl selenocyanate WC‐9 homologues, which are interesting compounds with potential biological activity against Trypanosoma cruzi, the etiological agent of Chagas disease. The synthetic sequence involves the application of the photo‐Fries rearrangement reaction as a key step for the preparation of a series of 2‐hydroxyphenones bearing alkyl chains of different length and a phenyl group. These intermediates are obtained upon direct irradiation (254 nm) of 4‐phenoxyphenyl esters in different solvents at room temperature. Then, reaction of the 2‐hydroxyphenones with 2‐(2‐bromoethoxy)tetrahydro‐2H‐pyran followed by acid deprotection, tosylation (or mesylation) reaction and, finally, nucleophilic attack with potassium selenocyanate provides the target aryloxyethyl selenocyanate homologues in good yields.