19752-57-9

10527-69-2

19752-57-9

The general procedure for the synthesis of 1,3-dibromo-5-iodobenzene from 2,6-dibromo-4-iodoaniline is as follows: 1. Preparation of 3,5-dibromoiodobenzene: 188.4 g of 2,6-dibromo-4-iodoaniline and 600 g of hypophosphorous acid were added to the reaction vessel at room temperature and stirred well. Subsequently, a solution formed by dissolving 34.5 g of sodium nitrite in 60 ml of water was added dropwise. The reaction is violently exothermic and the reaction temperature needs to be controlled at 20-25°C by means of a water bath. After the dropwise addition was completed, the reaction was continued for about 3 hours until a large white solid precipitate was observed. The reaction was continued at this temperature for 1 hour. The progress of the reaction was monitored by HPLC and stopped when the raw material 2,6-dibromo-4-iodoaniline completely disappeared. The crude product was collected by filtration. 2. Purification of the crude product: the crude product was dispersed in three 1000 ml flasks, 700 ml of anhydrous ethanol was added to each flask, and the product was heated to reflux (ca. 80 °C) to completely dissolve the product. Subsequently, it was cooled to 20-25 °C, the crystals were collected by filtration and dried under reduced pressure at 60 °C to obtain white needle-like crystals of 136 g. The purity of the product, 3,5-dibromo-2-iodobenzene, was 99.72% by HPLC analysis and the reaction yield was 75.2%.