1,4-Dioxane → 4,5-Dichloro-2-formylbenzoic acid

Participants

Reaction Steps

A suspension of 3-bromo-5,6-dichloro-3H-isobenzofuran-1-one (2.0 g) in 5% aqueous HCl (10 mL) and 80% aqueous dioxane (25 mL) was heated to reflux for 2 hours. The solvent was removed and the resulting residue re-dissolved in ethyl acetate, dried (magnesium sulfate) and concentrated. The resultant yellow solid was recrystallized from DCM/hexane to give the sub-title compound as a white solid (1.13 g, 73%). 1H NMR (400 MHz, CDCl3) δ 6.66 (0.84H, s), 7.95 (0.16H, s), 8.05 (0.84H), 8.12 (0.16H, s), 8.14 (0.84H, s), 8.41 (0.84H,), 10.41 (0.16H, s), 11.07 (0.16H, brd s) ppm.

Provenance & Evidence