SU658118A1 - Method of cyclic dimerization of conjugate diens - Google Patents

Description

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This invention relates to petrochemical synthesis, in particular to the preparation of six-membered cyclic dimers of conjugated dienes.

Six-membered limers, such as zenylcyclohexene, 3-methyl-4-propenylcyclohexene, dipentene, are used in the petrochemical industry. They are used as starting compounds for the preparation of D1 epoxies, as solvents in the paint industry, as raw materials for the production of peroxide and hydroperoxide compounds, as starting compounds for the synthesis of organoaluminum compounds.

Known methods for dimerization of conjugated dienes using homogeneous catalysis, for example, synthesis of vinylcyclohexene using organoaluminum compounds (1 .. The disadvantages of this method include the high fire and explosion hazard of the catalytic systems used and strict requirements on the initial monomers. If the olefins contain the slightest amount of water then the catalyst is immediately completely destroyed and the process stops.

Also known is the method of terdary dimerization of conjugated dienes, which allows the isolation of a mixture of six-membered piperylene dimers. This method also has a number of significant drawbacks: stringent experimental conditions, high pressure and duration of the experiment. These factors are aimed at introducing the method into pro- duction. Isoprene, under the conditions of thermal dimerization, gives a large number of higher oligomeric products, and this reduces the yield of the target products 2.

The closest to the invention in its technical essence is the method of cyclic dimerization of butadiene using as a catalyst metals Zi, At, 5p, Co, Ni, Pd, or their mixture as a suspension in a solvent, such as aromatic or paraffinic carbon / hydrogen or liquid butadiene or by applying metals to activated coal, asbestos, or other carrier. Dimerization is carried out at 160-200C 3.

The disadvantage of this method is the high consumption of catalyst, the impossibility of regenerating the latter and the difficulties associated with loading the raw material and catalyst and isolating the desired product from the reaction mixture.

The purpose of the invention is to simplify the process technology.

This goal is achieved by the described. Method of cyclic dimerization of conjugated dienes, carried out in the presence of a metal alloy of nickel-titanium and aluminum as a catalyst with a weight ratio of 47-50 metals:; 1-10 42-50. The process is carried out at a temperature of 120-1 ° C. Dimerization can be carried out both in the gas phase and in the liquid phase, in the latter case using inert solvents. The catalyst was regenerated by washing with a 3% aqueous solution of alkali, alcohol, and cyclohexane. The catalyst is then calcined at 250 ° C for 20 hours and reused.

The technological design of the process of dimerization of olefins using a heterogeneous catalytic system is much easier than with thermal dimerization or using a homogeneous catalytic system. High pressure apparatus and high temperature are not required. The process is easier to automate, it is easier to control the conditions of the reaction.

The method is illustrated by the following examples.

Er and me p1. Cyclic dimerization of isoprene.

Through a flow reactor C 50, d 2 cm, filled with an Ab alloy in the ratio of 47: 3: 50 s. With a grain size of 1.0 mm, isoprene is passed at a rate of 1.60 hours. The temperature in pe iKTOpe is maintained at 130140 ° C. Reaction mass: after exit, cooled to, the condensed dimers are separated, and isoprene is allowed to be recycled. In one pass / up to 29.1% of isoprene, IB dimers are converted. According to GLC, the product is an individual compound — dipentene, b.p. 61-62 / 15; , 4760. IR spectrum, -Sm-; 890, 3060 (methylene group); 810.3020 (CH-SJ); HLR spectrum (tf, m, E.): 1.58 (3N); 1.65 (ZN); 4.63 (2H); 5.29 (H). The yield of dipentene to the reacted isoprene is 97.8%.

Example 2. Cyclic dimerization of a mixture of cis- and transpentadiene 1,4. Dimerization uses pentadiene containing, according to LC, 60% trans-Form and 40% cis-form.

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Isoamylene is used as a solvent.

Catalyst skeletal Rene nickel, promoted by titanium, obtained by leaching 25% of aluminum from an alloy of composition: 50.0 wt.%; Ni; 5 47.0 wt% Av; 3 weight% Ti.

The catalyst was tested in the dimerization of pentadiene-1,4 in the liquid phase at a temperature and pressure of 10 atm. A mixture of 64.3 wt.% 0 1,4-pentadiene and 35.7 wt.% Isoamy, flax is passed with a bulk velocity rfo to liquid pentadiene 1.0 h. A fraction of the following composition is obtained: i- + CjH 50.8 wt.%, Di5 pentadiene measures 48.35%, oligomers 0.81%. The conversion of pentadiene is 1.4 with 76.6%, and the yield of cyclodimeric for decomposed pentadiene is 98.2% for missed pentadiene Q -1.4 - 75.2%.

Catalyst productivity 512 g / l per hour.

The product is 3-methyl-4-propenyl-cyclohexene (80%), 3-methyl-5-propenyl-cyclohexene (10%),

3, 4-dimethyl-5-vinylcyclohexene (3%),

3,5-dimethyl-4-vinyl-cyclohexene (2%). In addition, the reaction mass contains up to 5% of a mixture of unidentified compounds. The identification of the products is carried out by comparison with known compounds by GLC.

Example 3. Cyclic dimerization of butadiene.

/ V -

The catalyst used

0 Ni-Ti -AE alloy in a ratio, wt.%: 47: 3: 50.

Pass through the flow reactor gaseous butadiene, get with 92% yield of individual

g vinylcyclohexene. Conversion diene per pass is 30%. Product Constants: T.kip. 127-128s; IR spectrum, t) cm; 710; 730; 910; 1000; 1640; 3020; PMR spectrum, ((f, M, d.).

Example 4. An industrial mileage cycledimerization of pentadiene-1,4 was carried out on an alloyed nickel-aluminum-titanium catalyst under industrial conditions.

5 The pentadien-containing fraction with a pentadiene concentration of 1.4 40.3 87, 1 wt.% After pre-rectification from the heavy is carried out in contact with the catalyst in a 180-liter flow-type reactor.

The data characterizing the effect of the main process parameters on the yield of cyclodimers pentadiene — 1.4, 65 are presented in the following table.

the yield of pentadiene-1,4 dimers is from 35.45 to 48.8 wt.%. The yield of cyclodimers on decomposed pentadiene-1,4 is 96-98%. The conversion of the monomer and the yield of the missing pentadiene-1,4 depend on the concentration of the latter in the initial mixture. For a mixture containing 87.1 wt.% Pentadiene-1.4, monomer conversion 57 wt.%, The yield of the missed monomer is 56.1%.

Catalyst productivity: 497 g / l.

For a mixture containing pentadiene-1, 4, 64.3% by weight of the conversion was 76.6% by weight, and the yield of the missed monomer was 75.2%.

Catalyst productivity 664 g / lh

Example 5. Cyclic dimerization of trans-piperylene

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Trans-piperylene is passed through a flow reactor filled with 40 ml of alloy catalyst Ni: Ti: A6 49: 1: 50 at a rate of 1.60 hours.

Conversion of the diene in one pass is 32%. The unreacted product represents an individual trans-piperylene, which again nycKcUOT in reaction.

According to GLC, cyclic dimers consist of two peaks. Bp mixtures 55-65 / 12 mm; n§f 1.4550. Methods preparative chromatography

740, 965, 1380, 1460, 3020; PMR spectrum, ((f, m, d.) 0.83 (3H,; ji7); 1.56 (3N, Jr7); 4.8-5.5 (4H); I1 / e: i36. Product for all the parameters coincide with 3-methyl-4-propenylcyclohexene.

The second pic T.kip. 180 (760 mm) P 1.4740, IR spectrum, O cm-710, 745, 970, 1380, 14GO, 1640, 3020; H-NMR (H, m, d): 0.82 {3H, 37) j 1.68); 5.50-6.00 (4th); “Yeah. 0.36.The product in its constants coincides with Z-methyl-5-propenyl-cyclohexene.

Example 6. Trans-piperylene is passed through the zone of a flow reactor filled with 40 ml of alloy catalyst N-i: Ti: AC "48:10: 42 at a speed of 1.60 hours.

Conversion of the diene in one pass is 32%. According to GLC, cyclic dimers consist of two peaks: 3-methyl-4propenyl-cyclohexene and 3-methyl-5-propenyl-cyclohexene.

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Claims (2)

1. A method of cyclic dimerization of conjugated dienes at elevated temperature in the presence of a catalyst, characterized in that, in order to simplify the process technology, a metal alloy of nickel-titanium-aluminum is used as a catalyst with a weight one. 7 ratio of metals equal to 47-b; ; 1-10: 42-50, 2. The method of Claim 1, of which is that the process is carried out at a temperature of 120-160s. Sources of information taken into account in the examination of f) S and 1 1 8 8 1. In eppeg jv. and flp.Svnihe e voncisГ15-C cEooclodierii .B undcis-t.z-HivirivC-Cvceo-butcin. App., 727.16 (, f969. 2. Nazarov, I.I., Kuznetsova, L.I., Ku: Netsov, N.V., Limonization, Isoprenl. - JOH, 25, 1955, p. 307. 5 3, Japan Patent No. 40-6455, class, 16 C 81, 1965.