反应详情

The reaction is performed in a 1 L 3-necked flask equipped with a mechanical stirrer, a Dean-Stark trap topped with a condenser and a nitrogen bubbler, and a stopper. The flask is flushed with nitrogen and charged firstly with potassium hydroxide (22.4 g, 0.4 mol), α,α,α-trifluoro-m-cresol (64.8 g, 0.4 mol), and toluene (500 mL). The mixture is stirred and heated at reflux for 2 h, during which water collected in the trap (ca. 6 mL). 1,4-Dibromobenzene (94.4 g, 0.42 mol) and cuprous chloride (39.6 g, 0.4 mol) are added, and heating a reflux is continued for another 18 h. The reaction mixture is analyzed by capillary GC which shows ca.45% of the title product along with ca.10% of the dialkylation product, with the rest being starting materials. The mixture is filtered with the aid of ether (200 mL), and washed successively with 2×100 mL portions of 5% HCl (to remove any residual copper impurities), water, and brine. It is then dried (MgSO4) and concentrated on the rotary evaporator to a red oily residue. TLC (silica gel) shows four components (Rf =0.00, 0.15, 0.35, 0.70, CH2Cl2). Fractional distillation afforded 42.9 g (34%) of the title compound, distilling at 112-116° C. @ 1 mm. Also obtained was 12.1 g (10.5%) of the dialkylation product, distilling at 160-165° C. @ 1 mm.

1. customThe reaction is performed in a 1 L 3-necked flask
2. customequipped with a mechanical stirrer
3. customa Dean-Stark trap topped with a condenser
4. customThe flask is flushed with nitrogen
5. temperatureheated
6. customcollected in the trap (ca. 6 mL)
7. temperatureheating a reflux