Antioxidant 245 synthesis

Yield:36443-68-2 95%

Reaction Conditions:

with nitrogen in water;toluene;2,2'-[1,2-ethanediylbis(oxy)]bisethanol;

Steps:

2.2 EXAMPLE 2

(2) Into a 1-liter four-necked flask equipped with a stirrer, a condenser, a thermometer, and a nitrogen introducing tube were introduced 327.9 g (1.31 moles) of methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 85.6 g (0.57 mole) of triethylene glycol, and 0.9 g (0.00431 mole) of monobutyltin oxide. The mixture was allowed to react at 170° C. for 1 hour, and the resulting methanol was distilled off. The reaction was continued for further 8 hours under a reduced pressure of 60-70 mmHg while bubbling nitrogen gas into the solution and thus completed. Excess methyl 3-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate was distilled off in an amount of 40.5 g at 150°-185° C. under 0.5 -0.2 mmHg by thin film distillation. This distillate can be reused, as it is, for the next reaction. Then, the reaction mixture was cooled to 115° C. and returned to atmospheric pressure by the introduction of nitrogen gas, and dissolved homogeneously by adding 260 g of toluene. The solution was washed with 200 g (0.11 mole) of 5% oxalic acid water at 80° C. and then with 200 g of water twice for partitioning to two layers. The toluene layer was concentrated at 120° C. under 30 mmHg to give a pale yellow tacky substance. The pale yellow tacky substance so obtained was recrystallized from methanol-water to Yield 317.8 g of white crystals of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] as intended. Yield: 95%, residual tin content: 2 ppm.

References:

US5081280,1992,A