Solid-phase synthesis of n,n-disubstituted s,n'-diarylisothioureas: facile exchange reactions of isocyanates.

Reactions of resin-bound 1,1-disubstituted-2-arylisothioureas 4aa',ab'-ec' with aryl isocyanates, diversely substituted at the para and/or meta positions, and with o-fluoro- and 2,4-difluorophenyl isocyanate followed by appropriate cleavage led to the formation of N,N-disubstituted S,N'-diarylisothioureas 9[1-70] in good yields and high purities.