Derivatization with phenylisocyanate for HPLC monitoring of chemical reactions

A method of monitoring the progress of a chem. reaction carried out on a solid support comprises (a) derivatizing a sample of a bound compd. with phenylisocyanate (PIC) as a labeling moiety, (b) cleaving the derivatized compd. from the solid support, and (c) detg. the amt. of derivatized compd. by HPLC with UV detection. The reaction of several arom. aldehydes with resin-​bound β-​alanine to produce a series of imines was monitored by HPLC using the PIC derivatization method to det. the amt. of unreacted β-​alanine present. The superior and consistent results from the PIC method were obtained over a mass spectrometric method.