General procedure for the synthesis of 2-bromo-5-iodobenzyl alcohol from 2-bromo-5-iodobenzoic acid: Tetrahydrofuran (99.7 g) and sodium borohydride (15.2 g, 0.4 mol) were added to a reaction flask, followed by a solution of tetrahydrofuran (151 g) of 2-bromo-5-iodobenzoic acid (109.4 g, 0.34 mol, prepared according to Example 2), and the temperature was controlled to be in the range of 10-25°C. A solution of tetrahydrofuran (25 g) of sulfuric acid (16.4 g) was added slowly and dropwise to the reaction vessel at 10-30°C. -25°C. A tetrahydrofuran (25 g) solution of sulfuric acid (16.4 g) was slowly added dropwise at 10-30°C to the reaction vessel. After the dropwise addition was completed, the reaction was carried out at room temperature for 2 hours. Subsequently, the reaction mixture was heated to 66°C and refluxed for 2 hours and then cooled to room temperature. 5% hydrochloric acid (235 g) was slowly added dropwise, followed by distillation under reduced pressure (~0.01 MPa) to remove the tetrahydrofuran. Methyl tert-butyl ether (326.7 g) and water (222.7 g) were added to dissolve the solids and after cooling to 15-25°C, the organic layer was separated and evaporated under reduced pressure (-0.095 MPa). Toluene (108.8 g) and water (108.8 g) were added and the mixture was heated to 60°C and kept for 1 hr, then cooled to 18-22°C. It was filtered and dried to give 89.1 g of an off-white solid product, which was assayed to contain >99%, giving a yield of 85.1%.
