DE2035504C3 - Process for the production of cumene hydroperoxide - Google Patents

Description

is implemented. 65 employed. Trials A, B, C, D, and E were

According to the method of the invention can be comparative tests with or without known Ra accordingly Cumene in cumene hydroperoxide around the wall dispenser and with or without potassium fluoride, where the rate of formation of the hydro were guided, while experiment F after the

Method of the invention was carried out. The results obtained are shown in the following table:

attempt Free radical donors Theatrical Version Thiosulfr.t No. (0.01 g) Cg) (ml) A. 0 0 2.2 B. 0 5 0.48 C. Dibenzoyl peroxide 0 6.2 D. Dibenzoyl peroxide .5 7.6 E. Azobisisobutyronitrile 0 16.3 F. Azobisisobutyronitrile 5 36.1

As the comparison of experiment A and B shows, potassium fluoride, when it is alone present, sets the speed the formation of cumene hydroperoxide in the first phase of the reaction. The experiments C and D show that dibenzoyl peroxide in combination with potassium fluoride leads to the formation of cumene hydroperoxide only slightly increased compared to dibenzoyl peroxide alone. From the comparison of experiments E and F, however, the synergistic ίο effect of the combination of potassium fluoride and azobisisobutyronitrile clearly results on the formation of cumene hydroperoxide.

Claims (1)

ι ² peroxide from this catalyst combination via patent claim surprisingly increased synergists and thus the "The reaction process necessary for the production of cumene hydroper- time for a given yield is considerably reduced. oxide by oxidation of cumene with oxygen 5 The implementation of the process of the invention or an oxygen-containing gas in the presence is carried out be. a reaction temperature of from SO to azobisisobutyronitrile, dadurchgeke η n- 15O ⁰ C, e.nem pressure yon about 0 5 at 25 and a bs characterized in that cumene with an oxygen Müiverhaltn.s preferred; of oxygen to carbon-containing gas in a molar ratio of O ₂ to hydrogen of about 1: 5 to 2: 1, with preferably cumene of at least about 1:10 in the presence of "1 to 5 percent by weight Kal.umfluond and 0.01 to from about 0.009 to 5 percent by weight azobisiso- 2 percent by weight «,« -azobisisobutyronitrile anutyronitrile and about 0.1 to 10 percent by weight can be used. Kaliumfiuorid, each based on the weight Since the Kal.umfluond during the reaction in of the cumene, is present at a temperature of 80 to solid form, it should preferably be finely divided 150 ⁰ C and an oxygen pressure of 0.5 to 15, ie have a grain size of less than about 0.5 mm, 25 at is converted. ^{in order to present a large} specific surface area. The cumene hydroperoxide obtained can be fractionated by the usual measures such as filtration Distillation, selective extraction and their combinations can be obtained from the reaction mixture. The invention relates to the production of the process according to the invention appears to be directed towards this Cumene hydroperoxides are based on oxidation of cumene that alkali metal halides cause the decomposition of with oxygen or an oxygen-containing gas. Hydrocarbon hydroperoxides in free radicals Processes of this type are known. It is also delaying. However, free radicals are likely to be the formation leannt to catalytically stimulate the oxidation of cumene in the presence of another cumene hydroperoxide, free radical forming compound, e.g. B. one The alkali halide thus allows a higher Hydroperoxide or peroxide to make or a final concentration of the hydroperoxide, however, continues tuleiten to shorten the induction period. by lowering the concentration of the stimulating It has also already been suggested that the rate of formation be free radicals at the beginning turned down alkali halides, such as potassium fluoride, to the 30th of cumene hydroperoxide. At the beginning of the reac hydrocarbon before the hydroperoxidation, the azobisisobutyronitrile evidently provides the Rusetzen because these alkali halides remove the hydroper- necessary proportion of free radicals in a synergioxid yield increase. static interaction with the potassium nitride, This advantage of the alkali halides is, however, the disadvantage without the higher final concentration of cumene hydroper opposed to the fact that they prevent the formation of hydroperoxide, which is stabilized by potassium nitride the first stages of hydroperoxidation. delay reaction. As an oxidizing agent for the invention From DT-AS 19 00 145 it is known that cumene-based processes are pure oxygen, air or hydroperoxide in the presence of alkali fluoride and mixing oxygen with inert gases such as nitrogen, if necessary use a small amount of Cumene Hydroper-40. to produce oxide as an initiator. In this interpretation, the cumene hydroperoxide obtained is a valuable one However, writing is stated and in the examples intermediate compound in the production of acetone proves that the addition of cumene hydroperoxide in the and phenol. Reaction mixture before the oxidation reaction. The following example is intended to illustrate the method of is started, do not explain any further significant improvement in the connection
driving brings. . . . It has now been found that a from Azobisiso- e 1 s ρ 1 e butyronitrile and potassium nuoride existing catalyst In a 300 ml stainless steel autoclave 43 g latorkombinalion surprisingly capable of cumene, 5 g of potassium nitride and 0.01 g of r \, a'-azobisisoist, the conversion of cumene into its hydroperbutyronitrile or, as a comparison substance, dibenzoyl oxide given peroxide especially in the first phases of the reaction. The autoclave was 35 minutes to accelerate considerably. heated to 93.3 ° C for a long time and pure oxygen with The invention relates to a method for pressing 21.1 at. The reaction content was with Production of cumene hydroperoxide by oxidation with a magnetic stirrer and stirred for 1 hour at 93.3 ° C held by cumene with oxygen or an oxygen 55. Then the reaction mixture was 1 hour hooked gas in the presence of azobisisobutyronitrile, cooled for a long time and taken 5 ml samples in which which is characterized in that cumene with one of the content of cumene hydroperoxide according to the iodine / Oxygen-containing gas in a molar ratio thiosulfate standard method by Wagner, Smith from oxygen to cumene of at least about 1:10 and Peters, Anal. Chem. 19: 979 (1947) in the presence of about 0.009 to 5 percent by weight 60 was. In the iodine / thiosulfate method, the be-azobisisobutyronitrile and about 0.1 to 10 ml of the thiosulfate standard required by weight to the one obtained percent potassium fluoride, in each case directly proportional to the amount of cumene hydroperoxide. The normal weight of the cumene, at a temperature of 80 to tat of the thiosulfate was 0.1. 150 ^° C. and an oxygen pressure of 0.5 to 25 atm. 6 experiments were carried out with the above method