N,N′-Carbonyldi[1,2-benzisoxazol-3(2H)-one]: New, Reactive Condensing Agent

A new condensing agent, N,N′-carbonyldi[1,2-benzisoxazol-3(2H)-one] (6), was readily prepared by the reaction of 1,2-benzisoxazol-3-ol and trichloromethyl chloroformate in toluene. The condensing agent 6 was shown to be very useful for the preparation of amides, esters, and dipeptides under mild conditions. A successful polyamide synthesis by one-pot polycondensation of isophthalic acid with diamines using 6 was also described.