A polymeric reagent for derivatization of weak nucleophiles in HPLC-UV

Microporous and macroporous polystyrene beads are modified to contain various activated centers to which are attached a detector-sensitive label useful for analytical-scale derivatization of nucleophilic species. The effect of surface area, porosity, and percent cross-linkage of the polymeric support containing an o-nitro activated ester is investigated. The polymers are characterized by a loading determination to calculate the amount of active acylating reagent incorporated per gram of dry polymer. The kinetics of reaction with substrates of varying steric hindrance vs. solvent strength are determined with the optimized polymeric support and a second polymeric reagent is synthesized based on that support. The second polymer contains a hydroxybenzotriazole functionality. This polymer has increased electrophilicity and is used to prepare a much stronger acylating reagent than the polymeric o-nitrobenzophenol when labeled with 3,5-dinitrobenzoyl chloride. The polymeric hydroxybenzotriazole (HoBTA-DNB) is able to derivatize much weaker nucleophiles such as alcohols, thiols, and phenols at room temperature in less than 30 seconds.