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.