Rink Amide resins
Rink amide resins are the standard supports for the production of primary carboxamides and sulfonamides by solid phase synthesis. Following removal of the Fmoc group (if present), the resin-bound amino group can be acylated using standard methods of amide bond formation. The resulting amide group is stable to a wide range of reaction conditions but is easily cleaved from the resin by treatment with 95% TFA.
Two types of Rink amide resin are available: in the first the benzhydrylamine handle is linked directly to the polystyrene base matrix via an ether bond (Rink amide resin); in the second the Rink amide linker is attached to an appropriate amino-functionalized resin via an amide bond (Rink AM resin, Rink MBHA resin, and NovaSyn® TGR). The latter resins are generally regarded as the more robust, particularly under acidic conditions, as they do not contain a potentially acid sensitive benzylic ether linkage.