Sulfuric Acid → HCID 57475644, compound

Participants

Reaction Steps

A RBF equipped with a reflux condenser was charged with 4-bromophenol (15.5 g, 89.4 mmol), 2,5-diiodobenzoic acid (25.700 g, 68.7 mmol), EtOAc (0.337 ml, 3.44 mmol), and toluene (100 mL). Cs2CO3 (44.8 g, 137 mmol) was carefully added portion-wise. After stirring at RT for 1 min, the mixture was heated to 50° C. for 40 min and then heated to 100° C. for 20 hrs. The reaction mixture was allowed to cool to RT. The mixture was filtered through Celite and the solids were washed with EtOAc. The filtrate was diluted with water (200 mL), acidified with 2N HCl (300 mL), and extracted with EtOAc (4×500 mL). The organic extract was washed with brine and dried over sodium sulfate. The organic fraction was concentrated under reduced pressure to afford crude 2-(4-bromophenoxy)-5-iodobenzoic acid (31.1 g) as a tan oil that solidified upon standing. Step 2: H2SO4 (73.3 ml, 1375 mmol) was added to 2-(4-bromophenoxy)-5-iodobenzoic acid (28.800 g, 68.7 mmol) at rt. The resulting dark mixture was heated to 60° C. for 45 minutes. The brown solution was poured slowly onto ice-water (1 L) with stirring. The resulting tan precipitant was collected by filtration, washed with water a 1 N solution of NaOH, again with water, and dried under reduced pressure to afford 2-bromo-7-iodo-9H-xanthen-9-one (23.4 g) as a tan solid that was used without further purification.

Provenance & Evidence