SU338087A1 - Method of preparing alkylidene substituted norbornenones - Google Patents

Abstract

1335138 Isomerizing alkenyl norbornenes VSESOJUZNY NAUCHNO - ISSLEDOVATELSKY INSTITUT SINTETICHESKOGO KAUCHUKA IMENI AKADEMIKA LEBEDEVA 7 July 1971 [28 July 1970] 31819/71 Heading C5E Alkylidene norbornenes are produced by isomerizing alkenyl norbornenes in the presence of a three-component catalyst comprising an alkali metal or ammonia complex thereof, a carrier and a compound of an alkali metal or alkaline earth metal. The carrier (e.g. Al 2 O 3 , silica gel, aluminium silicate or a zeolite) may be promoted with the compound of an alkali or alkaline earth metal (e.g. potash or NaOH) and may be mixed with molten alkali metal or impregnated with a solution of alkali metal in liquid ammonia. The isomerization may be carried out in hydrocarbon solution. Examples describe the isomerization of vinyl norbornene to ethylidene norbornene and of isopropenyl norbornene to isopropylidene norbornene.

Description

The invention relates to methods for producing alkyl-substituted norbornenes, for example 2-ethylidenebicyclo- (2,2,1) -heptene-2, which can be used as a third monomer in the production of rubber-like copolymers of ethylene and propylene, which can be vulcanized with sulfur.

A known method for producing alkylidene substituted norbornenes, e.g. ehilidenenorbornene, by isomerizing alkenyl norbornenes, e.g. vinyl norbornene, in the presence of alkali metals or their ammonium complexes on a carrier with a highly developed surface as a catalyst. However, this process is not effective enough. The prolonged contact time of the reactants, as well as the elevated temperature (about 80 ° C.) Lead to gum formation and catalyst deactivation.

The invention is aimed at increasing the efficiency of the process, as well as preventing gum formation.

To achieve this goal, a catalyst support pre-promoted with alkali or alkaline earth metal compounds is used.

in aliphatic, aromatic or cyclic hydrocarbons or mixtures thereof.

The alkali metal can be LITHIUM, potassium, or sodium, preferably sodium, which is the cheapest and is relatively safe to use.

The carrier can be any material with a highly developed surface. Most suitable for this is alumina, which is produced in large quantities by industry, is easily activated and regenerated,

As compounds of alkaline and alkaline-earth metals used to promote a carrier, oxides, hydroxides and SALT can be recommended. It is best to use potash, since it is cheap, commercially available in large quantities, highly soluble in water and stable at high temperatures (alumina activation temperature 400-500 ° C).

Isomerization of vinyl norbornene or its 10-50% solution is carried out with a minus of 20 - PLUS 80 ° C. And atmospheric pressure.,

Five such solvents, in the medium of which the process of obtaining copolymers is carried out, for example, bispium.

Example 1 (control). For the preparation of the catalyst, alumina of grade A-1 is used with a magnitude of fraction; eggs of 0.25-0.5 mm. To activate, aluminum oxide is flushed with argon for 4 hours at 400-500 ° C.

Under stirring with argon current, hot sodium oxide, which has been previously washed from oil, is fed into hot activated alumina from (calculated as 4.0 wt.%, Calculated as alumina. The resulting catalyst contains 4.0 wt.% Of metallic sodium.

To carry out the isomerization reaction, 22.5 g of vinyl norbornene is fed to a glass stirred reactor equipped with a thermometer and a tube for sampling during the reaction, then 0.5 g of sodium containing catalyst are then poured in with stirring. During the reaction, samples are taken, which are analyzed for the content of ethyldeinorbornene (EPB) in the reaction mixture by gas-liquid chromatography. The results are shown below.

The amount of sweat ua, counting on Al.jO ,, weight. %

5 15

N ip m. 3. Reaction — isomerization is carried out continuously. For isomerization, a solution of vinyl norbornene in gasoline is used, the volume ratio is 1: 3. The catalyst is prepared on alumina promoted with 15 wt. % potash, according to the method described in example 2.

For carrying out the isomerization reaction, a glass column with a Shott filter is used, in which the finished catalyst is loaded in the amount of 6.5 g. The content of sodium in it is 8.15 wt. % or 0.57 g

The volumetric feed rate of the solution of vinylorbornene 4.0 catalyst. The temperature at the inlet to the reactor support 20-25 ° C.

Under these conditions, the catalyst is operated for 7–0 hours with 100% conversion of vinyl norbornene to ethylidene norbornene. With further experimentation for another 10 hours, the conversion slowly decreases and reaches

Content of ENB

Reaction time

REALITIONAL Amesi, wt. % min

9.0

5 10 15 20 30 60

9.2

9.3

9.1 9.2 9.1

The temperature at the beginning of the reaction is 25 C. The maximum temperature increase during the reaction is 26, G C.

When using untreated alumina as a catalyst carrier, the degree of conversion of vinyl norbornene. (VNB) in ethylidenenorbornene is very small.

Example 2. Increasing the activity of the catalyst when used as a carrier of alumina promoted with different quantities of potash.

To prepare the catalyst, alumina (from Example 1) is pretreated with an aqueous solution of potash. It is further dried for 4 hours at 200 ° C in air, and then the catalyst is activated and prepared according to the procedure described in Example 1. The experimental procedure and the amount of reagents used for the experiments are similar to those indicated in Example 1. The results are shown in Table. one.

T and b and j and 1

80%. According to the results of this experiment, for 1 kg of vinyl orbornene, 0.6 to 0.7 g of sodium is required for its 100% conversion to ethylidene norbornene.

Example 4 (control). Alumina from Example 1 is used. For the preparation of the catalyst, alumina is activated at 400-500 ° C by evacuation (3-5 mmHg) for 4-5 hours.

A jacketed glass reactor with a stirrer is condensed with ammonia, which is pre-dried with caustic potash and sodium metal. At the same time, the temperature in the reactor is maintained by a thermostat from mipus 40 - minus 50 ° C.

Claims (2)

Then sodium metal is fed into the reactor and the contents are mixed at minus 40 - minus, 50 ° C for 10-15 minutes. In the resulting ammonia solution, the concentration of which is 40–45 g / l of sodium, the activated alumina is slowly poured and the contents are gently stirred for 30 minutes, the ammonia is evaporated from the reactor and the finished catalyst is rinsed with argon for 15 hours at 80 ° C. in examples 1-2. The amount of catalyst is 1.5 g, the content of sodium in it is 0.075 g. Below are the results. Contents of ENB Reaction time, in the reaction mixture, min. Reaction start temperature 25 ° C. The maximum temperature rise during the reaction was 28.5 ° C. Hp and m p 5. The catalyst is prepared according to the procedure described in Example 4, but alumina is pre-promoted 15 wt. % potash, as described in example 2. The experimental procedure is similar to that described in examples 1 and 2. For the test, the catalyst is fed in an amount of 1.5 g, the sodium content in it is 0.075 g. Below are the results. Containing ENB Reaction time, in a reagent mixture; min weight % reaction 25 ° C. Start temperature The maximum temperature increase during the reaction is 50 ° C. H r and me 6. The catalyst and experimental procedure are similar to those shown in Example 5. Vinylnorbornene is used for isomerization as a 25% solution in gasoline. In the reactor pomesh, ayut 50 ml of solution. The amount of catalyst fed is the same as in Example 5. The results are shown below. Conversion VNB Reaction time, in ENB, wt. % min. The temperature of the onset of the reaction is 25 ° C, the maximum temperature rise in the reaction hight is 30 ° C. Example 7. A 25% solution of vinyl norbornene in gasoline in a continuous reactor is isomerized. The procedure and experimental conditions are similar to those described in Example 3. The catalyst was prepared using the ammonia method according to the procedure described in Example 5. 3.3, g of catalyst with a sodium content of 0.28 g was used to carry out the reaction in a continuous manner. The scientific research institute for isomerization under these conditions lasts 60 hours at 100% conversion of vinyl norbornene to ethylidene norbornene. Here, 0.7 g of sodium is consumed per 1 kg of vinyl norbornene. Claim 1. Method for producing alkylidenden-substituted norbornenes by isomerization of alkenylnorbones in the presence of basic catalysts, for example, an alkali metal, its ammonia com plexes, on a carrier, characterized in that, in order to increase the efficiency of the process, a carrier is used that has been previously promoted by compounds of alkali or alkaline earth metals . 2. A method according to claim 1, characterized in that the isomerization is subjected to an aliphenyl norbornene solution in aliphatic, apo; matic or cyclic hydrocarbons or mixtures thereof.