反应详情

In a three-necked, round-bottomed flask fitted with a stirrer, thermometer, reflux condenser with a trap to collect distilled off methanol and later isooctanol and a vacuum connection are added 200 g (0.684 mole) of methyl 3,5-di-tert-butyl-4-hydroxyhydrocinnamate, 178 g (1.37 moles, 100% excess) of isooctanol (Exxal®-8, Exxon) and 0.05 g (0.0000826 mole; 50 ppm of tin in final product) of butyltin tris-(2-ethylhexanoate) (Fascat® 9102, Elf-Atochem). The reaction mixture is subjected to a reduced pressure of 400 mm Hg and the flask is heated to 140°-150° C. Methanol begins to be evolved and is collected in the trap receiver. When the reaction mixture reaches 160° C., reflux of isooctanol is observed and becomes vigorous at 170°-180° C. while the evolution of methanol subsides. At this point, the excess isooctanol is then stripped into the trap receiver and the pressure in the system is ultimately reduced to 5 mm Hg. When all the excess isooctanol is removed, the residue in the flask is cooled under nitrogen and is the desired title compound in essentially quantitative yield (over 99% by weight).

1. customIn a three-necked, round-bottomed flask fitted with a stirrer
2. temperaturethermometer, reflux condenser with a trap
3. customto collect
4. distillationdistilled off methanol and later isooctanol