O-Xylene → 2(3H)-Benzofuranone
반응식
C([C:5]1[CH:6]=[C:7](C(C)(C)C)[C:8]2[O:12][C:11](=[O:13])[CH:10](O)[C:9]=2[CH:15]=1)(C)(C)C.CC1C=CC=CC=1C>O>[O:12]1[C:8]2[CH:7]=[CH:6][CH:5]=[CH:15][C:9]=2[CH2:10][C:11]1=[O:13]참가 물질
4
실험 절차
To a solution of 262.3 g (1.00 mol) of 5,7-di-tert-butyl-3-hydroxy-3H-benzofuran-2-one (compound (201), Table 2, Example la) in 500 ml (4.05 mol) of o-xylene are added 40 g of Fulcat 22B and the mixture is refluxed for 1.5 hours on a water separator. The Fulcat 22B catalyst is then removed by filtration and excess p-xylene is removed by distillation on a vacuum rotary evaporator. Crystallisation of the residue from 500 ml of methanol yields 244 g (69%) of 3-(3,4-dimethylphenyl)-5,7-di-tert-butyl)-3H-benzofuran-2-one, m.p. 130-132° C. (compound (103), Table 1), which additionally contains c. 1.3% of the structural isomer [3-(2,3-dimethylphenyl)-5,7-di-tert-butyl-3H-benzofuran-2-one, compound (103A)]. The mother liquor yields a further 42.4 g of product which, according to GC-MS analysis, consists of 12.3% of the compound (103) and 87.7% of the isomeric compound (103A).