A convenient one-pot synthesis of N-substituted amidoximes and their application toward 1,2,4-oxadiazol-5-ones.

The first direct one-pot approach for the synthesis of N-substituted amidoximes from secondary amides or the intermediate amides has been developed. Through the Ph(3)P-I(2)-mediated dehydrative condensation, a variety of N-aryl and N-alkyl amidoximes (R(1)(C[double bond, length as m-dash]NOH)NHR(2), where R(1) or R(2) = aryl, alkyl, or benzyl) were readily afforded under mild conditions and short reaction times. The synthetic application of the obtained amidoximes has also been demonstrated through the formation of 1,2,4-oxadiazolones via base-mediated carbonylative cyclization with 1,1'-carbonyldiimidazole.