N-Cyclohexylcarbodiimide,N′-methyl polystyrene

N-Cyclohexylcarbodiimide, N-methyl polystyrene ^[1] is an ideal tool for mediating solution phase coupling reactions. Typically, the amine and carboxylic acid are treated with a 2-3 fold excess of resin in DCM or DMF ^[2,3]; a slight excess of carboxyl component over amine component is often used to help drive the reaction to completion. As excess acid and urea by-products remain attached to the resin at the end of the reaction, the product can normally be isolated pure by filtration and evaporation of the reaction mixture. Reactions can be accelerated by the addition of auxiliary nucleophiles such as HOBt; these can be removed using polyamine- or TBD-polystyrene. This resin has also been used in conjunction with DMAP to mediate ester formation ^[4].

Associated Protocols and Technical Articles
Protocols for Loading of Peptide Synthesis Resins

Literature references

^[1] G.M Weinshenker, et al. (1988) Org. Synth., Coll. Vol. VI, 951.
^[2] Y. Guan, et al. (2000) J. Comb. Chem., 2, 297.
^[3] K. Senton, et al. (2003) J. Comb. Chem., 5, 336.
^[4] M. Cano, et al. (2002) J. Org. Chem., 67, 129.

Color (visual): slightly beige to brown
Appearance of substance (visual): beads
Loading (determined by HPLC after reaction of Z-Phe-OH with cyclohexylamine): ≥ 1.3 mmol/g
Swelling Volume (in CH₂Cl₂): lot specific result
The polymer matrix is copoly (styrene-2 % DVB), 200 - 400 mesh.

Replaces: 01-64-0211

Novabiochem is a registered trademark of Merck KGaA, Darmstadt, Germany