Polyolefin fibers with chemically fixed active ester for the solid phase synthesis of an amide derivative

Reactive fibers having chemically fixed active ester were derived from chloromethylstyrene grafted polyethylene-coated polypropylene staple fiber and non-woven cloth. First, chlorine atoms in each fiber were substituted by mercapto groups, and the resulting fibers were reacted with N-hydroxymaleimide to obtain fibers containing chemically fixed N-hydroxysuccinimide moieties. These fibers were converted into reactive fibers having chemically fixed active ester by reaction with a model carboxylic acid (3-(2-bromophenyl)propionic acid) in the presence of a condensing reagent (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) in excess. Performances of both reactive fibers in the model amide synthesis were compared by their reaction with 2-phenylethylamine. Although the reactive non-woven cloth gave an amide contaminated with unknown organic impurities, the reactive staple fiber yielded highly pure product. Possible causes of this difference are discussed on the basis of SEM observation of both fibers.