Zhichkin Paul E, Peterson Lisa H, Beer Catherine M, Rennells W Martin
Medicinal Chemistry Department, AMRI, 26 Corporate Circle P.O. Box 15098, Albany, New York 12212, USA.
J Org Chem. 2008 Nov 21;73(22):8954-9. doi: 10.1021/jo8017186. Epub 2008 Oct 17.
N,N-Dimethylformamidine and novel N,N-diisopropylformamidine protecting groups were used to carry out a one-pot conversion of aminobenzoic acids into the corresponding amides. General conditions for an in situ transformation of aminobenzoic acids and their heterocyclic analogues into the corresponding formamidine-protected acid chlorides were developed. These chlorides were used in reactions with amines, including poorly reactive anilines. The protected amides were then smoothly deprotected by heating with ethylenediamine derivatives, resulting in a general procedure for the one-pot transformation of aminobenzoic acids into their amides. Our one-pot procedure was successfully applied to the preparation of several compounds of pharmaceutical interest.
