Anionic Synthesis of Aromatic Carboxyl Functionalized Polymers. Chain-End Functionalization of Poly(styryl)lithium with 4,5-Dihydro-4,4-dimethyl-2- [4-(1-phenylethenyl)phenyl]oxazole

Abstract

The novel syntheses of 4-(4,5-dihydro-4,4-dimethyl-2- oxazolyl)benzophenone, 1-[4-(4,5-dihydro-4,4-dimethyl-2-oxazolyl)phenyl]-1-phenylethanol and 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole (1) are described. ω-Oxazolyl polystyrene (2) was synthesized in quantitative yields by the reaction of poly(styryl)lithium with stoichiometric amounts of 4,5-dihydro-4,4-dimethyl-2-[4-(1-phenylethenyl)phenyl]oxazole (1) in toluene/tetrahydrofuran (4 :1 v/v) at -78°C. Deblocking of the oxazoline protecting group by acid hydrolysis followed by saponification quantitatively provides the corresponding aromatic carboxyl chain-end functionalized polystyrene (3). The functionalization agent and functionalized polymers were characterized by HPLC, thin layer chromatography, size exclusion chromatography, vapor phase osmometry, spectroscopy ( 1 H NMR, 13 C NMR and FTIR), potentiometry and elemental analysis.