t-Butoxycarbonyl-PEG4-sulfonic acid contains a t-Butyl ester group and sulfonic acid group. The t-butyl ester group can be converted to free acid group under acidic conditions. The resulting acid readily reacts with amine and alcohol under coupling conditions. The sulfonic acid is know to undergo esterification, halogenation and replacement reactions. The PEG spacer increases the aqueous solubility of the resulting compound.
Axispharm offers 3000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.