Synthesis of N,N-Diethylbenzamides via a Non-Classical Mitsunobu Reaction.

The use of the Mitsunobu reaction for the synthesis of N,N-diethylbenzamides affords ortho-, meta-, and para-substituted benzamides, containing both electron-donating and electron-withdrawing groups. While the preparation of numerous functional groups has been efficiently demonstrated employing the Mitsunobu reaction, our methodology represents the first application of the Mitsunobu reaction for the construction of benzamides using benzoic acid and amine starting materials. Moreover, this synthetic transformation is believed to proceed via a non-classical mechanism involving the existence of an acyloxyphosphonium ion.