Abstract: A process is provided for the preparation of hydroquinone by oxidizing a phenol having in the paraposition a 1-cycloalkenyl or .alpha.-methylene-(alkyl or aralkyl) group. The oxidation is carried out using hydrogen peroxide or a hydrocarbyl peroxide in the presence of an inert solvent and a catalytic amount of a strong acid which is not oxidized by the peroxide. The other product of the reaction is the ketone derived by oxidation of the para-substituent in the starting phenol, e.g. p-isopropenylphenol gives hydroquinone and acetone. The reaction forms a particularly convenient route for conversion of phenol to hydroquinone in that phenol is condensed with acetone to bisphenol A, the latter is degraded by alkaline hydrolysis to a mixture of phenol and p-isopropenylphenol, which latter is subjected, without separation, to the above process to give a mixture of hydroquinone, phenol, and acetone.

Abstract: Benzene or alkylbenzene (e.g., toluene) is alkylated with propylene to produce diisopropylbenzenes or isopropylalkylbenzenes, which in turn are selectively cracked to remove the 1,4-isomer. The resultant product, containing a high level of the 1,3-isomer, is then oxidized to 1,3-dihydroxybenzene or 3-alkylphenol (e.g. 3-methylphenol) in significant yield.

Abstract: A four-step method for the selective production of the 1,3-isomer of methylphenol comprising the alkylation of toluene with propylene in the presence of a specified type of zeolite alkylation catalyst followed by the selective reaction, via a specified type of shape selective zeolite, of the 1,4-isomer of the alkylation product to leave the 1,3-isomer thereof in excess of equilibrium. Subsequent oxidation and acid catalyzed rearrangement results in desirably high yield of 3-methylphenol.

Abstract: Isopropylphenyl esters are converted to di- or trihydric phenols via a novel autoxidation of the esters at high conversion rates to the corresponding hydroperoxyisopropylphenyl esters in the presence of a catalyst combination comprising at least two members selected from the group consisting of (i) a metal phthalocyanine; (ii) a di-tertiary alkyl peroxide; and (iii) a tertiary alkyl hydroperoxide.Rearrangement of the hydroperoxyisopropylphenyl esters to the corresponding hydroxyphenyl esters and the hydrolysis of the latter compounds provides the phenols in overall yields (from the starting esters) heretofore not obtainable. Novel bis(hydroperoxyisopropylphenyl)carbonates are described which are attractive intermediates for the intermediate bisphenol carbonate or the final hydroquinone hydrolysis product.

Abstract: An organic hydroperoxide is hydrolyzed by acid-catalysis in a reaction medium comprising essentially a mixture of a polar solvent, e.g. a low boiling, low molecular weight alcohol and/or sulfolane and phenol. Specifically cyclohexanone and phenol are obtained from cyclohexylbenzene hydroperoxide.

Abstract: Hydroquinone having a purity greater than 99 percent is isolated through an aqueous recovery scheme compatible with the methyl isobutyl ketone based diisopropylbenzene dihydroperoxide isolation process. Hydroquinone, from the Hock-splitting reaction, is extracted into water while the impurities are concentrated in a distillation tower. Phase separation of the distillation tower bottoms affords an efficient separation of the hydroquinone from the organic impurities. Concentration, crystallization, and solid liquid separation (centrifugation) of the aqueous phase yields a wet hydroquinone cake which, upon recrystallization from acetone, yields high purity hydroquinone.

Abstract: Hydroquinone is obtained in greater than 95 percent yield through a nonaqueous recovery process compatible with the methyl isobutyl ketone (MIBK) based diisopropylbenzene dihydroperoxide isolation process. Hydroquinone, from the Hock-splitting reaction, is precipitated (after most of the reaction solvent is distilled off), separated, repulped in acetone, crystallized and separated again. The supernatant from the first separation step contains hydroquinone along with tars. This stream is subjected to a purification process comprising a series of distillation and extraction steps so that the hydroquinone in that stream can be recycled back into the process.

Abstract: A process whereby photograde quality hydroquinone can be separated from the reaction mixture produced by a rearrangement of p-diisopropylbenzene dihydroperoxide, which process comprises the steps of (1) subjecting the mixture to hydrogenation to remove color; (2) concentrating the colorless solution; (3) adding a solvent to the concentrated mixture which dissolves impurities but which causes the hydroquinone to precipitate; and (4) separating the hydroquinone from the supernatant liquid in step (3).