Poly(p-acetoxystyrene) resin: a prospective new support for combinatorial synthesis

Abstract

A range of spherical particulate resins have been prepared in high yield by suspension polymerisation of mixtures of p-acetoxystyrene (AS), styrene (S) and divinylbenzene. The particle size is typically 100–400 µm. The functional group content has been varied from ca. 15–60% and the degree of cross-linking from ca. 2–20%. Macroporous and gel-type species have been identified. Hydrazinolysis offers a facile and high conversion hydrolysis route to the free phenolic function independently of overall functional group loading, with the phenol content of resins being quantified by two independent methods. Further chemical modification of the phenol functions has been examined. Reaction with bromine is essentially quantitative, and attachment of dichlorotriazine residues occurs specifically by a single linkage even for heavily loaded resins. Subsequent displacement of chloride from the triazine residues by 2-aminomethylpyridine is again essentially quantitative.

These transformations suggest that p-acetoxystyrene-based resins offer an attractive complementary support to chloromethylated resins for exploitation in, e.g., the combinatorial synthesis of libraries of organic compounds.