2,6-dibromobenzene-1,4-diol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Dissolve 2,6-dibromo-4-methoxyphenol (23.0 g, 80.6 mmol) in CH3CN (400 mL) and add trimethylsilyl iodide (TMSI) (53 mL, 371 mmol). Reflux the solution for 4 hours and add more TMSI (50 mL, 371 mmol). Heat the reaction at reflux overnight and cool to ambient temperature. Pour into ice-H2O (700 mL) and extract with EtOAc (2×300 mL). Wash the combined extracts with saturated sodium hydrosulfite (200 mL), H2O (200 mL) and brine (100 mL), dry over MgSO4, filter and concentrate. Crystallize the residue to provide the subtitled product (21.36 g, 98%) as a tan crystalline solid. Reflux the solution for 4 hours Heat the reaction at reflux overnight extract with EtOAc (2×300 mL) Wash the combined extracts with saturated sodium hydrosulfite (200 mL), H2O (200 mL) and brine (100 mL) dry over MgSO4 filter concentrate Crystallize the residue