DE1493030C3 - Process for the preparation of 1 - (5'-indanyl) -3-phenylpropane - Google Patents

Description

IO

as-hydrindacene

It is known that Friedel-Crafts catalysts such as aluminum chloride and boron trifluoride are capable are, various rearrangements and isomerizations of paraffinic and hydroaromatic Catalyze hydrocarbons.

In the publication in "Reports of the German Chemical Society", Vol. 57 (1924), S. 1990 to 2003, the use of aluminum chloride for various rearrangement and cleavage reactions described, for example for rearrangement from tetrahydronaphthalene to octahydroanthracene or phenanthrene and benzene.

From Topciev, Zavgorodnij and Pa u sk i η "Boron trifluoride and its compounds as catalysts in organic chemistry" (Berlin 1962), S. 220 and 221, it is known that various isomerizations, especially of paraffins, with the help of Boron trifluoride can be made.

The isomerization of octalines with the aid of HBF ₄ is described in Proceedings of the Chemical Society, Volume 1960, p.412, and from DT-PS 3 33 158 it is known that treatment of tetrahydronaphthalene with aluminum chloride at elevated temperature results in hydroaromatic Hydrocarbons, especially octahydroanthracene and octahydrophenanthrene in addition to benzene, can be obtained.

It has now been found that a very selective reaction for the production of l- (5'-indanyl) -3-phenylpropane can be carried out when indane is under specific reaction conditions treated with liquid hydrogen fluoride and boron trifluoride.

Accordingly, the invention is a process for the preparation of l- (5'-indanyl) -3-phenyl-propane, which is characterized in that one indan at 10 to 45 ° C, preferably liquid at about 30 ⁰ C, with at least 1 mole Treated hydrogen fluoride and at least 0.5 moles of boron trifluoride for no more than about 3 hours.

It has been shown that in the presence of HF - BF ₃ indane is converted in high yield and that this reaction leads very selectively either to as-hydrindacene or to 1 - (5'-indanyl) -3-phenylpropane, hereinafter also referred to as IPP referred to, the product obtained in each case mainly depends on the reaction temperature. It has also been shown that in the presence of HF - BF _3, the IPP obtained can also be converted into as-hydrindacene.

The conversion of indane in the presence of hydrogen fluoride and boron trifluoride can in principle

Indan

IPP

The method according to the invention is carried out in detail as follows:

HF should be used in the liquid phase. Although the reaction above the boiling point of HF (19.4 ^'0 C) can be carried out and this measure is preferred, the pressure in the reaction vessel should be sufficient to maintain HF in the liquid phase. All boiling points given here relate to a pressure of 760 mm Hg abs., Unless otherwise stated. Normally the pressure of the BF ₃ (boiling point = - 101``C) in the reaction vessel is sufficient to keep the HF in the liquid phase, unless other convenient measures are taken to ensure the use of liquid HF, such as creating a pressure in the reaction vessel with nitrogen, etc. The amount of HF used must be at least 1 mole per mole of indane, but is preferably at least 4 moles, in particular at least 8 moles per mole of indane. Preferably the HF: indane molar ratio does not exceed about 50: 1, but ratios up to 200: 1 or higher can optionally be used.

The amount of BF ₃ must be at least 0.5 mole per mole of indane and is preferably at least 0.7 mole per mole of indane. Although some reaction product is obtained with BF ₃ : indane-MoIV ratios between 0.1: 1 and 0.5: 1, there is a very rapid and drastic increase in the yield when the ratio exceeds 0.5: 1. _{The BF 3} : indane ratio is particularly preferably at least 1: 1. The yield of the reaction product is usually maximized at a BF ₃ : indane ratio between 0.5: 1 and 2.0: 1. As a result, the amount of BF ₃ normally used will not exceed 2 moles per mole of indane, but amounts of up to 10 moles per mole of indane or even larger amounts can optionally be used. The examples clearly show the effect of the BF ₃ indane ratio on the yield of the reaction product.

From the above it can be seen that the molar ratio of HF to indane is at least 1: 1, preferably at least 4: 1 and in particular

should be at least 8: 1. The hydrogen fluoride should be used in the liquid phase. The MoI ratio of BF ₃ to indane should be at least 0.5: 1. preferably at least 0.7: 1.

The reaction temperature used in each case determines the end product. At relatively low levels Temperatures are high yields of IPP with virtually complete exclusion of as-hydrindacene achieved. As the temperature rises, the yield of IPP falls and so does the yield of as-hydrindacene, until finally high yields of as-hydrindacene at relatively high temperatures can be obtained with the substantial exclusion of IPP.

Accordingly, in the preparation of 1- (5'-indanyl) -3-phenylpropane according to the invention, the reaction temperature is 10 to 45 ° C. Since the yield of IP P tends to reach a maximum at about 30 ° C., the particularly preferred reaction temperature I is about 30 'C. The influence of the reaction temperature: the reaction product and its yield is' ■ apparent from the examples below.

The reaction time, ie the time in which the HF-BF ₃ comes into contact with the indane, does not exceed 3 hours for the production of IPP. The minimum response time will normally be 10 minutes, more often 30 minutes.
j The reaction can take place in any of the usual ways; Can be carried out using a conventional device. For example, the starting material is; added to a closed reaction vessel equipped with means for heating and stirring. Since the reaction temperature is lower than the melting point of the indane, it is dissolved in an inert solvent such as hexane or heptane. The required amount of HF is then added, whereupon the HF-indane mixture is heated to the desired reaction temperature. The mixture is then added the desired amount of ₃ ^j BF, followed by: the vessel is preferably shaken or the contents are stirred for ¹ in some other way to provide an effective contact of the i HF-BF ₃ catalyst to ensure the indane. After the BF _{3 has been added} to the reaction mass, it is then kept at the reaction temperature for the desired time. The BF ₃ is added after the reaction temperature has been reached because no reaction takes place as long as the BF _{3 is} not added. Since the products obtained are dependent on the reaction temperature, it is generally desirable that no reaction proceed until the desired temperature is reached.
■ After the response time has been completed, that alone is sufficient; Opening the vessel to remove most of the BF ₃ (Kp: = -101 ⁰ C) and most of the HF, when the reaction above its boiling point (19.4 ° C) is performed. Any remaining HF and any BF ₃ that is dissolved therein can be distilled off from the vessel.

It is also desirable to use the HF as a liquid

and not to be removed from the reaction vessel as a gas if it is below the limit after the reaction time has elapsed : half a temperature of 19.4 ° C, assuming

': that the reaction is above the boiling point of HF

■■ is carried out. The vessel is then opened, with most of the BF _{3 being} removed, and the remaining reaction mass is removed with ice water; frightens. Two layers of liquid arise, one

I aqueous acid layer and an organic layer.

If desired, the acid in this two-phase system can be neutralized _{by mixing the system with Na 2} CO _3. The organic layer is then decanted and preferably washed several times with water to remove any trace of acid or any trace of Na ₂ CO _3.

The organic layer then becomes 1- (5'-indanyl) -3-phenylpropane by chromatographic route

ίο or separated by vacuum distillation. IPP is distilled from the organic layer at about 150 to 155 ° C / 0.7 mm Hg, or about 195-200 ^ü C / 13 mm Hg.

The following example illustrates the production of IPP from indan. The one for comparison approaches carried out in which the conditions according to the invention were not met, clearly show that outside the conditions according to the invention, significantly smaller amounts of IPP, however, when the temperature range which is favorable according to the invention for IPP is exceeded, to a higher one At higher temperatures, larger amounts of as-hydrindacene are formed.

example

This example includes three approaches which are run at a constant HF: indane molar ratio of 10: 1 during a reaction time of 90 minutes were carried out. The remaining reaction conditions are shown in the table below, in which the yield of as-hydrindacene and in each batch IPP is specified.

A 75 ml shake bomb was used as the reaction vessel, which is equipped with facilities for Heating and cooling was equipped. The bomb was purged with nitrogen and then evacuated.

Then Indan and then HF were poured into the bomb. Indane was added in an amount of 0.1 mol; the same amount was used in all batches. The bomb was shaken, heated to the desired reaction temperature and then BF _{3 was} added. In all approaches, the BF ₃ pressure was sufficient to keep essentially all of the HF in the liquid phase. The bomb was then kept at the desired reaction temperature for the required reaction time, the reaction time being measured _{from the addition of BF 3.} Shaking of the bomb was continued throughout the reaction period. When the reaction time had elapsed, the bomb was cooled to 20 ° C., opened and its contents quenched in ice. Two liquid phases formed, an aqueous acid layer and an organic layer. The two-phase system was _{neutralized with Na 2} CO ₃ , after which the organic layer was drawn off and washed several times with twice its volume in water.

After the completion of the reaction, the reaction product was passed out from the organic layer Chromatography and elution separated and isolated. The chromatography column contained a kieselguhr adsorbent from Johns Manville Corp., based on 15% silicone rubber (SE-54, Analytical Engineering Laboratories, Inc. Conn.). The products were eluted from the column with helium.

Time - 90 minutes
HF: indane ratio = 10: 1

Approach .. MoIBF ₃ / Reac indane yield

No. MoI ... Conversion-as-Hy-

Indan ment drindacen IPP

: o, 64
': o, 6i;

0.61

so

12.6

94.8

0 8.0

.2.1. .80.1

34.5 ', 45.5-

The values in the table clearly show how crucial the reaction temperature is in order to form the desired reaction product. As mentioned above, the optimum temperature for the formation of as-Hydrindacen is about 70 ⁰ C and about 3O ⁰ C for the production of IPP. The data also show that high yields of reaction product are obtained. For example, if one divides the stated yield of IPP at 30 ° C. by the proportion of indane that has been converted, one can determine that about 90% of indane which took part in the reaction formed IPP. .:

Claims (1)

Claim: Process for the preparation of 1- (5'-indanyl) -3-phenylpropane, characterized in that indane is mixed at 10 to 45 ¹ C, preferably at about 30 "C, with at least 1 mol of liquid hydrogen fluoride and at least 0.5 mol of boron trifluoride not treated for longer than about 3 hours. run with the formation of as-hydrindacene or IPP, the temperature used in each case is crucial. what product will be obtained. The theoretical reactions involved in this conversion expire are as follows: