Phthalic Acid → Phthalic Anhydride

Participants

Reaction Steps

Phthalic acid (2.5 mmol), 2,6-bis(diisopropylaminomethyl)phenylboronic acid (hereinafter, referred to as “boronic acid compound A”, 0.25 mol) as an arylboronic acid catalyst, and heptane (10 mL) as a solvent were added in a flask having a volume of 20 mL, and a column (small Soxhlet extractor) filled with dried molecular sieves 3A (approximately 3 g) was fitted to the flask. The mixture was heated for 12 hours under azeotropic reflux conditions with the removal of water. After the reaction mixture was cooled to room temperature, heptane was evaporated under reduced pressure. The crude product of phthalic anhydride thus obtained was analyzed by 1H NMR (CDCl3), and the yield thereof was calculated. When the same procedure was repeatedly performed a plurality of times, the yield was 72% to 81%.

Provenance & Evidence