DE1059903B - Process for the production of phenylcyclohexyl hydroperoxide - Google Patents

Description

GERMAN

M34184IVb / 12o

REGISTRATION DATE: MAY 15, 1957

NOTICE THE REGISTRATION AND ISSUE OF THE EDITORIAL:

June 25, 1959

In the patent application M 32055 IVb / 12o the basic conditions for the oxidation of phenylcyclohexane to phenylcyclohexyl hydroperoxide are described, with concentrations and yields of hydroperoxide that have not yet been achieved. It is already known that the rate of oxidation of phenylcyclohexane to the corresponding hydroperoxide can be increased at the start of the reaction by adding various substances.

For this purpose, formaldehyde, optionally in Presence of cumene hydroperoxide and NaOH added.

It has also been found that other products, for example nickel oxide or other nickel compounds, strongly accelerate the beginning of the oxidation of phenylcyclohexane to hydroperoxide. However, in both cases, when using formaldehyde as well as nickel compounds, a large number of by-products, probably from the decomposition of the hydroperoxide; large losses eventually occur of phenylcyclohexane, which can no longer be converted into hydroperoxide.

This can be seen very clearly from Example 7 of the aforementioned patent, which is found can that the very high rate of hydroperoxide formation in the course of the first hour very quickly decreases as soon as a concentration of 16% hydroperoxide is reached.

If the oxidation were to be continued after this time had elapsed, the phenylcyclohexane would disappear completely without an increase in the hydroperoxide concentration being ascertained at the same time. Once a concentration of 18 to _20/0 is reached hydroperoxide °, the phenylcyclohexane disappears completely though, but there is a decrease in the content of hydroperoxide as a result of the formation of undesirable byproducts. This has been confirmed by experiments.

It has been found that can then be obtained under the conditions indicated 32055 IVb / 12o good in patent application M yields increase Oxydationsverlaufs with simultaneous reduction of the losses by side reactions up to 70 ° / _0, based on virtually quantitative Oxydationsausbeuten, at the same concentrations if the oxidation is carried out in the presence of 4 to 5% cumene hydroperoxide with the highest possible hydroperoxide content, which is added at the start of the reaction. To carry out the improved process according to the invention, phenylcyclohexane, to which cumene hydroperoxide has been added in as pure a form as possible, is heated to 100 to 115.degree. The cumene hydroperoxide must be very pure, no more than 10% other manufacturing processes
of phenylcyclohexylhydroperoxYd

Addition to patent application M 32055 IVb / 12 ο
(Interpretation document 1 033 658)

Applicant:

Montecatini, Societä Generale

per rindustria Mineraria e Chimica,

Milan (Italy)

Representative:

Dipl.-Ing. Dipl.-Chem. Dr. phil. Dr. techn. J. Reitstötter, Patent attorney, Munich 15, Haydnstr. 5

Claimed priority:
Italy 23 May 1956

Paolo Giarratana, Cesare Ferri, Angelo Passini

and Bruno Ponzini, Milan (Italy),

have been named as inventors

Contain substances. The oxidation is preferably carried out by blowing in air.

In order to determine the course of the oxidation, the oxidation product and the unreacted phenylcyclohexane are dissolved out of part of the reaction mixture recovered quantitatively.

The product obtained is dissolved in H ₂ SO ₄ and acetone and the unreacted phenylcyclohexane is recovered by fractional distillation.

Under the aforementioned conditions, the oxidation of phenylcyclohexane is practically quantitative Exploit.

The advantageous results obtainable by the procedure according to the invention are shown below Comparative tests compiled.

The apparatus used consists of a 500 ccm flask with a central and three lateral attachment tubes and is equipped with a screw stirrer, thermometer, oxygen inlet tube (the one with a fine opening under the Liquid level ends) and equip the gas outlet pipe with a still.

The flask is immersed in a bath of polyglycol and is turned on by an automatic thermostat Maintained 105 to 106 ° C. The still ends in a collecting vessel cooled with dry ice.

909 558/459

In the case of the apparatus, parts made of metal or rubber as well as sulfur-containing products were used avoided.

The oxygen supply was carefully controlled.

There were introduced 300 g of sulfur-free phenylcyclohexane (mp. 60 to 60.5 ⁰ C) to the flask.

The technical oxygen obtained from a steel cylinder fitted with a reducing valve was in proportion introduced from 6 to 7 1 per hour.

At the end of the operation, approximately 1 to 3 ecm of liquid was found in the collecting vessel.

The hydroperoid formed was determined by the standard iodometric method, which is also used for the determination of cumene hydroperoxide was applied.

The results of the experiments are shown below Table compiled and indicated in the graphic representation.

I. Phenylcyclohexane oxidation with oxygen at 105 ^° C

Operating hours 0 I 9 j. 16 I 22.50 I 29.50 | 36 | 42.50 | 49 | 56.30 | 60 | 63

66 I 6S

A 'volume percent hydroperoxide

0.25

0.31

6.95

13.15

20.6 29.8

33.6

36.3

37.9

Containing II. Phenylcyclohexane oxidation with l ° / ₀ powdered Na ₂ CO ₃ oxygen at 105 ⁰ C

Operating hours 7.5 j 14 I 20.5 | 27 | 33.5 | 44 | 50.5

56

62.5 I 66

Volume percent hydroperoxide

0.16

1.34

6.26 I 9.86

6.8

21.3

24.2

26.4

25.8

III. Phenylcyclohexane oxidation 0 with 0.1% of 50% NaOH solution containing 5 11 operation
18th hours
24.5 35 Oxygen at 105 ^° C 48.5 52.5 0 2.5 0.21 1.26 4.3 8.85 18.7 42 27.3 25.8 Percentage by volume of hydroperoxide 0.08 25.1

IV. Phenylcyclohexane oxidation containing 0.5% of 38% NaOH solution oxygen at 105 ⁰ C

5 j 11.5 I 18.5 operating hours
25 I 32 I 38.5 I 45.5 I 48.5

52

Volume percent hydroperoxide

0.14

0.8

5.33

10.9

16.3

22.6

24.55

24.8

There is no need to explain the obvious negative influence of the addition of alkali.

The invention is to be better illustrated by the following example.

example

854 g of melting point phenylcyclohexane 6 ° C and 44.2 g of 91.5% sodium Cuniolhydroperoxyd are supplied to a glass tube having a diameter of 4.5 cm and 80 cm length, set in a by a thermostat at 107-108 ⁰ C. Heating bath is located and with a washing vessel that contains a glass step and is provided with an outlet pipe to which a cooler is connected for condensation of the liquid entrained with the exhaust gases. The initial concentration of total hydroperoxide, calculated as phenylcyclohexyl hydroperoxide, is 5.3%.

20 liters of air are passed through the washing vessel per hour. After 6 hours the concentration is on Total hydroperoxide (calculated as phenylcyclohexyl hydroperoxide) 13.2%; after 15 hours it is 24.88 percent by volume, this corresponds to 25.64 percent by weight of phenylcyclohexyl hydroperoxide, corresponding to an hourly rate 1.35% increase.

The same procedure was repeated four times under the same conditions, being in the same Response time achieved the same results.

In the subsequent treatment of the reaction product with sulfuric acid and acetone and subsequent fractionation of the dissolved portion, 679.9 g of phenylcyclohexane with a melting point of 6 ^° C. were recovered.
The total consumption of phenylcyclohexane was 174.1 g, of which 167.2 g had been converted into phenylcyclohexyl hydroperoxide, which corresponded to a yield of 96.05%.

Even with repeated recovery of phenylcyclohexane from the oxidation mixture, one always obtained the same results.

If the oxidation is carried out under the same conditions as above, but without the addition of cumene hydroperoxide by, a 20% hydroperoxide concentration is reached after 37 hours, which is a corresponds to an average hourly increase of 0.54%.

If the reaction product is treated in the manner described above by dissolving and distillation, 652.6 g of phenylcyclohexane are thus obtained back.

The total consumption of phenylcyclohexane is then 201.4 g, of which 167.2 g are converted into hydroperoxide resulting in an oxidation yield of 83% and a loss of phenylcyclohexane Side reactions corresponds to which is about four times as great as the loss in the previous example.

If the oxidation is carried out under the aforementioned conditions, but with the initial addition of cumene hydroperoxide repeated in amounts of 1 to 5%, the losses of phenylcyclohexane (due to side reactions) inversely proportional to the amounts of cumene hydroperoxide used.

Claims (2)

Patent claims: 1. Process for the production of phenylcyclohexyl hydroperoxide by oxidation of phenyl ίο cyclohexane with oxygen or oxygen-containing gases at elevated temperature, such as 100 to 115 ⁰ C, and optionally increased pressure according to patent application M 32055 IVb / 12 ο (German Auslegeschrift 1033 658), at which one works in the absence of reactive metals or their salts, as well as sulfur and reducing substances, the volatile substances that occur as by-products are continuously removed the reaction mixture removed, condensed, for the purpose of removing the acidic constituents with water and alkaline solutions and the unreacted phenylcyclohexane into the oxidation vessel recirculates, characterized in that in a known manner in the presence of cumene hydroperoxide, but works without the addition of other reactive substances. 2. The method according to claim 1, characterized in that one uses as an additive a cumene hydroperoxide which does not contain more than 10 ° / ₀ of other substances. Considered publications:
French Patent No. 1053,743;
Italian Patent No. 503 109;
Swiss Patent No. 213 248;
British Patent No. 712,264;
U.S. Patent No. 2,680,139. © 909 558/459 6.