Methanol → Glutaric Acid

Participants

Reaction Conditions

Reaction Steps

Glutaric acid-terminated PEG (P8G) was synthesized by dissolving 8-arm PEG-OH (20 g, 7.97 mmol OH or 1 equivalent OH) and glutaric anhydride (4.54 g, 39.84 mmol, or 5 equivalents) in chloroform (2.5 mL chloroform per 1 mmol OH). Pyridine (5 eq) was added dropwise, and the reaction mixture was refluxed at 80° C. for 24 hours under inert air. The product was diluted with MeOH (240 mL or 12 mL MeOH per gram of PEG), precipitated at −20° C. for 1 hour, and centrifuged at −5° C. The supernatant was discarded, and the MeOH wash procedure was repeated twice more. Following diethyl ether precipitations (180 mL or 9 mL ether per gram of PEG), the product was dried under high vacuum overnight to afford a white powder (97.6% yield, 100% conversion). See FIG. 21.

Provenance & Evidence