Acetic Anhydride → 5-Methoxy-1,3-dihydro-2-benzofuran-1,3-dione

Participants

Reaction Steps

Acetic anhydride (40 ml) was added to a mixture of 4-methoxyphthalic acid (30.8 g, 0.16 mol) in anhydrous tetrahydrofuran (150 ml) and the mixture was strirred and held at reflux for 4 hours. Upon cooling to room temperature the solvent was removed in vacuo to afford 4-methoxyphthalic anhydride (27.8 g, 99%) as an off white solid. 1H NMR (DMSO-d6) 8.02 (1H, d), 7.59 (1H, d), 7.49 (1H, dd), 3.97 (3H, s). MS: [M+H]+ 179.

Provenance & Evidence