R-2,2'-Bis(broMoMethyl)-1,1'-binaphthalene

60536-98-3

54130-90-4

The general procedure for the synthesis of the compound (CAS: 54130-90-4) from 2,2'-dimethyl-1,1'-binaphthyl was as follows: Example 1: A 2-liter cylindrical glass reactor equipped with a stirrer, a glass cooling jacket and a bottom drain tap was used. The reactor was configured with a fill connector for the addition of N-bromosuccinimide, thermocouples (connected to a digital display with a sensitivity of 0.1°C and a temperature recorder). The cooling jacket is connected to a thermostat and temperature control is achieved by circulating water with an accuracy of ±0.1°C. The temperature of the reactor is controlled by a thermostat. The exterior of the reactor was radiated by a fluorescent lamp ("VITALUX", 300 Watt) located 60 mm from the glass jacket. To the reactor, 212 g (0.75 mol) of 2,2'-dimethyl-1,1'-binaphthyl, 900 ml of chlorobenzene, 450 ml of water, 68 g (0.38 mol) of N-bromosuccinimide, and 0.52 g (0.005 mol) of sodium bisulfite were added sequentially. The temperature of the mixture was adjusted to 19-20°C under vigorous stirring (the temperature of the cooling brine was kept constant at 18.0°C throughout the experiment). Nitrogen was introduced to remove air from the reactor and light exposure was initiated under nitrogen protection. After about 5 to 10 minutes, the reaction was started and the temperature increased by about 5℃. After the temperature returned, the remaining N-bromosuccinimide was added in batches: 68g, 67g, 34g, 30g and 8g, with the last portion added about 1 hour after the start of the light exposure, for a total of 275g (1.55mol) of N-bromosuccinimide. Light exposure was stopped after 2 hours. The reaction mixture was heated to 40°C and the two phases were separated. The chlorobenzene phase was washed once with 450 ml of water and evaporated under reduced pressure. The distillation residue (brown solid) was stirred with 800 ml of hot methanol and pumped, the filter cake was washed with 200 ml of methanol and dried to give 290 g (88% yield) of 2,2'-bis-(bromomethyl)-1,1'-binaphthyl. HPLC analytical conditions: chromatographic column Hypersil; mobile phase n-hexane/ dichloromethane (96:4); flow rate not specified.