Vol. 75 reflux six hours and decomposed with 10 cc. of 5% acetic acid, and the ether solution was washed with aqueous sodium bicarbonate, dried and evaporated in nitrogen. The dark residue was taken up in 5 cc. of boiling benzene, cooled and filtered to give 0.35 g. of crude 1,4,9-trihydroxy-9-phenyl-2,3-benzofluorene as a brown solid, m.p. 222-226°( dec.) (other specimens melted as low as 185°), soluble in alkali. The substance was converted to 4-hydroxy-9phenyl-2,3-benzo-l-isofluorenone in ten minutes by acetic acid at 100°. 9-Hydroxy-9-phenyl-2,3-benzofluorene-1,4-quinone, obtained by oxidation of the hydroquinone in ether with silver oxide, formed bright orange-yellow prisms from ether, m.p. 193-194°. The compound gave a pink solution in alcoholic alkali, a greenish-yellow vat and a dark olive solution in sulfuric acid. The ultraviolet and visible absorption maxima in ethanol solution lay at 258 µ (log t 4.34), 308 (3.86) and 417 (3.41).
The phenolic antioxidant 2,6-di-t-butyl-£-cresol is converted by reaction with f-butyl hydroperoxide to 1-methyl-1-ibutylperoxy-3,5-di-/-butylcyclohexadiene-2,5-dione-4. This peroxide reacts with bromine in acetic acid to give in high yield 3,5-di-/-butyl-4-hydroxybenzaIdehyde.The efficiency of monohydric phenols as antioxidants varies widely with the type and position of substituents.2-4 Thus phenol itself, which has es-
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