SU607831A1 - Method of preparing 1,6-heptadiene - Google Patents

Description

(54) METHOD FOR OBTAINING 1,6-HEPTADIENE

i.

The invention relates to oi, 60 -diene and other non-conjugated diene hydrocarbon production agents by catalytic ring opening in a cycloolefin with acyclic olefins.

C, W -diene hydrocarbons are important petrochemical products. They can be used for the production of various bi- and polyfunctional derivatives: halides, oxides, polyglycols, aldehydes, etc.

It is known to obtain 0.60 - diene hydrocarbons by the pyrolysis of diesters lj.

However, the process is carried out under stringent reaction conditions and the selectivity is not high enough, and the starting materials used are not readily available.

A known method for producing 1,6heptadiene and other ciC / W diene hydrocarbons by reacting cyclic olefins-ethylene on a Mo (CO) / Af, 05 catalyst at 69 atm and 125s 2. When the reaction is carried out, cyclopentene and ethylene react in an autoclave for 2, 5 hour exit

The 1,6-heptadiene is I7.9f, while the Cyclopentene is in the liquid phase.

There is also known a method for producing 1, b-heptadiene and other non-conjugated diene hydrocarbons from cyclopentene and ethylene on an alumino-cobalt-molybdenum catalyst in a flow system 3}. At 130 s and ethylene pressure of 42 at, the degree of conversion of cyclopentene is 26.7%, and the selectivity for 1,6-heptadiene is 43%. In addition to 1,6-heptadiene, 1,6,11-dodecatriene and other non-conjugated polyene hydrocarbons are formed in significant quantities, with the cyclopentene being in the reaction in the liquid phase. This method is closest to the proposed one. However, this method is characterized by low selectivity for the target product — 1,6-heptadiene — and carrying out the process under stringent conditions.

The aim of the invention is to increase the selectivity and simplify the process.

The proposed method for the preparation of 1.6heptadiene is that cycropentene is reacted with ethylene in the presence of an aluminum catalyst promoted with a tin compound of the general formula </ BR> where 1 is lower alkyl, in the vapor phase at room temperature. The difference is in the process of carrying out the process in the vapor phase at room temperature in the presence of an aluminum catalyst promoted with a tin compound of the general formula where T is lower alkyl. During the process of interaction of cyclopentene with ethylene in the vapor phase at, atmospheric or elevated pressure in the presence of an aluminum catalyst, promoted by SnR, the selectivity reaches 95-98%. When converting cyclo pentene 13.5 - 22%, the method used in the catalyst is prepared by impregnation with a solution ammonium perrhenate. The promoting additive is applied in a solvent in amounts of 1-10% by weight of the catalyst, then the solvent is removed by a stream of inert gas. The precursors are fed by sparging ethylene through cycl pentene. In the practical implementation of the process ethylene recycling is necessary after condensation of the reaction products. The proposed method allows to obtain 1,6-heptadiene with high speed and selectivity from available raw materials. Example. The interaction of cyclopentene and ethylene is carried out in a flow type reactor on an aluminum catalyst, not promoted with experiment (1) and treated with 6k) (experiment 2). A catcher is prepared by impregnating an industrial Jf-AEJO with aqueous solution of ammonium perrhenate from a PC1 calculation of the preparation of a catalyst containing alumina and calcined beforehand. After impregnation and drying, the catalyst is treated with air for 1 hour, then with nitrogen at the same temperature for 1 hour and loaded into the p-actor in a stream of nitrogen. The catalyst thus obtained is promoted by impregnating it with a solution of (CdH) in pentane. The amount of &amp; m () is 5% by weight of the catalyst. Pentane is then removed in a stream of nitrogen. Cyclopentenes are supplied to the reactor by bubbling ethylene through cyclopenten, while the temperature of the bubbling is kept no higher than the temperature of the reactor. Due to this, the cyclopentenes in the reaction zone are in the vapor phase. The reaction products analyzed by gas chromatography. The products were identified by IR spectroscopy, NMR spectroscopy and mass spectrometry. The results of the interaction of cyclopenten and ethylene at the flue gas, the catalyst are given in table 1. From Table 1 it can be seen that during the process in the vapor phase, the selectivity of converting cyclopentene to 1,6-heptadiene is very high (not less than 98%). The formation of a small amount of 1,5-heptadiene is observed. No further conversion products 1, ygeptadiene (dodecatriene, etc.) are detected. However, the degree of conversion of cyclopentene is low (4.5%). The use of a modified catalyst makes it possible to significantly increase the degree of conversion of cyclopentene (up to 13.5%) while maintaining high selectivity. Example 2. To test the influence of the phase state of cyclopentene on the selectivity of the process, parallel experiments were carried out on an aluminum catalyst treated with 5N (CjjHj )) at a temperature of 20s and a pressure of 8.5 atm. In run i, cyclopentene is fed to the reactor from a high pressure dropper and it is in the reaction zone in the liquid phase. In Test 2, the cyclopentene is evaporated with ethylene from a bubbler and fed to the reactor in the vapor phase. Table 2 shows the effect of the phase state of cyclopentene on the selectivity of its interaction with ethylene on the catalyst (h From the table it can be seen that the phase state of cyclopentene has a decisive influence on the selectivity of the reaction. During the process in the liquid phase, the degree of cyclopentene is higher however, the selectivity for 1,6-heptadiene is significantly lower. In the case of cyclopentene in the vapor phase, the selectivity is 95%, despite the fact that the weight rate of cycloolefin was lower. 3. To test the effect of the structure of the alkyl radical in an organotin compound on the modification of the alumina catalyst, it is treated with 6M (The catalyst is prepared and activated according to the procedure described in Example 1. The amount of &amp; G1 () is 5% by weight Catalyst. It can be seen from the above data that the replacement of the hydrated rschelle in an organotin compound does not alter the modifying action of the catalyst.

Pokeatel

(()

Pressure of ethylene, ata temperature, С

Cyclopentene weight, h

Cyclopentene pressure, ata

The degree of conversion of cyclopentene,%

Selectivity for 1.6heptadiene,%

Indicators

Ethylene pressure, ata Temperature, s

Cyclopentene weight rate,

The degree of conversion of cyclopentene,%

The composition of the products, wt.%

cyclopenten

1,6-heptadiene 1,6, Ll-dodecatriene

higher polyenes

Selectivity for 1.6 - Hepdien,% Fraction C contains 95% 1,6-g. Indicators of the interaction of cyclopentene and ethylene on the catalyst K.O./A.O., “+ &amp; n (C, Hb, lc PS Ethylene pressure, ala0.95 Temperature, C20 Cyclopentene pressure, ata0.05 Weight rate by cyclopentene, hour Cyclopenene conversion rate,% 12.2 Selectivity for 1.6 heptadiene,% 98.0

Table

Experience

(.0- {6i () 1

0.95 20

1.0 0.05 13.5 98.0

6lit2

2 (vapor phase)

1 {liquid phase)

8.5

20

0.3 21.5

72.0 28.0

Claims (3)

-95.0 ptadiene and 5% 1,5-heptadiene. Claim 5: a method for producing 1,6-heptatidea puV .ilUwvJv - that interaction of cyclopentene and these topics of interaction of cyclopentene lene in the presence of a catalyst, of t - ",. Catalyst, of tl and h In order to simplify and increase the selectivity 60 of the process, an aluminum catalyst is used as a catalyst, promoted with a tin compound of the general formula 65 where R is lower alkyl, and the process is carried out in the vapor phase at room temperature. Sources of information taken into consideration during the examination: 1. USSR Copyright Certificate 258300, cl. From 07 To 11/12, 1970. 2. Belgium patent No. 694420, cl. From 07 V, 1970. 3. US patent No. 3527828, cl. 260677, 1973.