反应详情

A mixture of 309 g (1.50 mol) of 2,4-di-tert-butyl-phenol and 192 g (1.00 mol) of 4-allyloxymandelic acid (prepared in accordance with EP-B-182 507, Example 1, page 4) is stirred under nitrogen for 2 hours at 140°-150° C. Then the mixture is stirred under low vacuum (50 mbar) for 1.5 hours; at 150° C. Excess 2,4-di-tert-butylphenol is distilled off under a high vacuum. Crystallisation of the residue from xylene and ethanol gives 230.1 g (61% ) of 3-(4-allyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one of m.p. 112°-114° C.

1. stirringThen the mixture is stirred under low vacuum (50 mbar) for 1.5 hours
2. customat 150° C
3. distillationExcess 2,4-di-tert-butylphenol is distilled off under a high vacuum
4. customCrystallisation of the residue from xylene and ethanol