Reaction Rates for the Production of Selected Hormones by Solid-Phase Synthesis

Reaction rates have been measured for the production of selected bradykinins, angiotensins, and endorphins by solid‐phase synthesis. Reactor liquid concentrations are monitored by using a UV detector and flow cell. Experimentation has been limited to low excesses of the t‐Boc amino symmetrical anhydride. More than 500 attachments have been monitored. Most data obtained from resins with 1% cross‐linking show second‐order behavior with reaction rate constants between 0.5 and 8L/(mol‐s). The reaction rate is affected by chemical structures of both the attached amino symmetrical anhydride and the anchored amino terminus on the peptide fragment. Increasing reaction temperature and initial solution concentrations promotes reaction rate. The structure of the polymer support affects not only the reaction rate but also the observed reaction kinetics.