36443-68-2

6386-39-6

51590-67-1

856335-90-5

36443-68-2

(2) To a 1 L four-necked flask equipped with a stirrer, a condenser tube, a thermometer and a nitrogen introduction tube were added 327.9 g (1.31 mol) of methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 85.6 g (0.57 mol) of triethylene glycol and 0.9 g (0.00431 mol) of monobutyltin oxide. The mixture was reacted at 170 °C for 1 h while the resulting methanol was distilled. Subsequently, the reaction was continued for 8 h at a reduced pressure of 60-70 mmHg and nitrogen was continuously vented into the solution to ensure complete reaction. Upon completion of the reaction, 40.5 g of excess methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate was distilled by film distillation at 150-185 °C and 0.5-0.2 mmHg. This distillate can be used directly in the subsequent reaction. The reaction mixture was cooled to 115 °C and restored to atmospheric pressure by passing nitrogen, followed by addition of 260 g of toluene to dissolve the mixture homogeneously. The resulting solution was washed once with 200 g (0.11 mol) of 5% aqueous oxalic acid at 80 °C and twice with 200 g of water to separate the organic and aqueous layers. The organic layer was concentrated at 120 °C and 30 mmHg to give a pale yellow viscous substance. The mucilage was recrystallized with a mixed solvent of methanol-water to obtain 317.8 g of white crystalline triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]. The yield was 95% and the residual tin content was 2 ppm.