Probing solid-phase reactions by monitoring the IR bands of compounds on a single ''flattened'' resin bead

The resolution of the IR spectra recorded on a single resin bead is greatly improved by flattening the bead. This technique allows the differentiation of carbonyl groups of resin-bound compounds with minor structural differences. Three solid-phase reactions on Rink AM, Rink Amide and Wang resins were directly monitored by observing the disappearance and the appearance of the resolved carbonyl bands. It was possible to quantify the yields of two of the solid phase reactions directly on bead.