Phloroglucinol → 5-Chloro-1,3-dihydroxyacridone

Participants

Reaction Conditions

Reaction Steps

A 250-mL sealed reactor was charged with 2-amino-3-chlorobenzoic acid (8.58 g, 50 mmol, and 1,3,5-trihydroxybenzene (110 mg, 1.0 mmol). The mixture was then heated to 230° C. for 40 min. The solids melted after ˜10 minutes and stayed as liquid for ˜1 minute before solidifying again. The mixture was cooled to room temperature and acetone (600 mL) was used to break the solids and transferred to a 1-L Erlenmeyer flask. The slurry was stirred for 30 minutes with periodic breaking of the solid with a spatula2. The solid was filtered and washed with acetone (200 mL), affording a dark yellow to brown powder. The powder was then triturated in hot methanol (1.5 L) at 60° C. for 30 minutes and filtered after the slurry cooled to ˜30° C. and washed with methanol (200 mL) to afford the product 3 (4.87 g, 37%) as yellow solid. 1H NMR (DMSO-d6): 6.06 (1H, d, J=2.3), 6.81 (1H, d, J=2.0), 7.23 (1H, t, J=8.1), 7.87 (1H, d, J=7.3), 8.11 (1H, d, J=7.3), 10.64 (1H, s), 10.97 (1H, s): LC-MS: m/z+1=262.1.

Provenance & Evidence