Dicyclohexylcarbodiimide → Benzophenone

Participants

Reaction Conditions

Reaction Steps

8 g of a hyperbranched polyglycidol with an average molecular weight 2000, prepared according to W02000/37532 (Bayer A.-G.) and Sunder A. et al, Macromolecules, 32, 4240-4246 (1999), was dissolved in 200 mL dimethyl acetamide at 40° C. 12.9 g (62 mmol) DCC was added and the mixture was stirred for 30 minutes. 13.3 g (52 mmol) 2-(4-benzoylphenoxy)-acetic acid was added and the reaction was allowed to continue for 16 hours at 60° C. The precipitated DCU was removed by filtration and the solvent was evaporated under reduced pressure. The residue was treated with 150 mL dichloromethane and the mixture was cooled to 0° C. After one hour, precipitated DCU was removed by filtration and the solvent was evaporated under reduced pressure. The benzophenone substituted hyperbranched polyglycidol was purified by preparative size exclusion chromatography on a 60×2.5 cm column, PL-gel 10 micron, pore size=500 A, Mw range: 500-30000, supplied by Polymer Laboratories, using tetrahydrofurane, 5% acetic acid as eluent at a flow rate of 10 mL/min and a product load of 200 mg per run. The pooled fractions were evaporated under reduced pressure. The residue was redissolved in 1000mL methylene chloride, extracted with 500 mL brine, dried over MgSO4 and the solvent was removed under reduced pressure. 6.5 g of the benzophenone substituted polyglycidol was isolated. 1H-NMR-analysis showed that the isolated polymer was substituted with 7 benzophenone moieties on average.

Provenance & Evidence