RU2807193C1 - Method for producing 5,6-dihydrodicyclopentadiene - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing dihydrodicyclopentadiene. The method involves the interaction of dicyclopentadiene with molecular hydrogen when heated in a flow-type reactor in the presence of a catalyst immobilized on aluminium oxide, characterized in that the process is carried out at a temperature of 150°C, nanostructured copper particles obtained by chemical reduction of copper complex compounds are used as a catalyst, its gamma modification is used as aluminium oxide, hydrogen is supplied to the catalyst with a flow rate of 550-1100 l/(l_cat⋅ h), and dicyclopentadiene with a weight rate of 1.73-3.46 h^-1.

EFFECT: increased selectivity of the process and increased yield of the reaction product.

1 cl, 4 ex

Description

The invention relates to a method for the reduction of dicyclopentadiene, namely to a new method of selective hydrogenation leading to the production of dihydrodicyclopentadiene, which can be used in the polymer and pharmaceutical industries.

There is a known method for the selective hydrogenation of dicyclopentadiene into 5,6-dihydrodicyclopentadiene using a solution of palladium nanoparticles in propylene carbonate as a catalyst [Behr A., Manz V., Lux A. Highly selective monohydration of dicyclopentadiene with Pd-nanoparticles// Catal. Lett. 2013. V. 143. P. 241-245]. The process is carried out in an autoclave, the target product is formed with a selectivity of up to 95%. The work determined the best reaction conditions: 50°C, 5 atm _H2 , 2 h, product yield 77% with dicyclopentadiene conversion 88%.

The disadvantage of this method is the use of a solvent, auxiliary substances, an expensive palladium-based catalyst, and periodic organization of the process using increased hydrogen pressure.

There is a known method for the selective hydrogenation of dicyclopentadiene in solution with hydrogen in the liquid phase using finely dispersed platinum group catalysts at atmospheric pressure and moderate temperature (30-80°C) and subsequent isolation of the target product. The method is characterized by the fact that hydrogenation is carried out in a toluene solution in the presence of additives - functionally substituted aromatic compounds capable of adsorbing on the surface of the catalyst, such as p-oxydiphenylamine, hydroquinone, β-naphthylamine, p-phenylenediamine, 2,6-di-tert-butyl -4-methylphenol, in an amount of 1-5 wt. % based on the catalyst taken, and the isolation of the target dihydrodicyclopentadiene is carried out by distilling off toluene under reduced or atmospheric pressure [patent No. RU 2459793, IPC C07C13/47, C07C13/54, C07C13/547, C07C5/03, C07C5/05, B01J23 /40, B81B1/00, 2012].

The disadvantage of this method is the use of a solvent, auxiliary substances, an expensive platinum group catalyst and a periodic organization of the process.

The closest is the method of selective catalytic hydrogenation of dicyclopentadiene into dihydrodicyclopentadiene, in a medium of at least one inert solvent selected from the group of linear and branched C₃-WITH₈-alkanes, benzene and toluene, using at least one hydrogenating agent and at least one catalyst (supported by alumina, silica, carbon and zeolite, or unsupported) selected from platinum, palladium and nickel at excess pressure up to 40 atm [patent no. US 7078577, IPC C07C5/02, C07C5/05, 2006].

The disadvantages of the invention are: the use of expensive catalysts, the need to dilute dicyclopentadiene with inert solvents, low catalyst productivity, and the use of high excess hydrogen pressure.

The objective of the present invention is to develop a technological method for the selective reduction of dicyclopentadiene.

The technical result is to increase the selectivity of the process and increase the yield of the reaction product.

The stated technical result is achieved in a method for producing dihydrodicyclopentadiene, which consists in the interaction of dicyclopentadiene with molecular hydrogen when heated in a flow-type reactor in the presence of a catalyst immobilized on aluminum oxide, and the process is carried out at a temperature of 150°C; nanostructured copper particles obtained as a catalyst are used chemical reduction of copper complex compounds, its gamma modification is used as aluminum oxide, hydrogen is supplied to the catalyst at a flow rate of 550-1100 l/(l _cat ⋅h), and dicyclopentadiene at a weight rate of 1.73-3.46 h ^-1 .

The essence of the method is the partial reduction of dicyclopentadiene with hydrogen at atmospheric pressure in the presence of nanostructured copper particles immobilized on γ-Al ₂ O ₃ , obtained by chemical reduction of copper complex compounds. The advantages of the method are the high selectivity of the process up to (100%), high yield of the target dihydrodicyclopentadiene (97%) with complete conversion of the original dicyclopentadiene using inexpensive, readily available catalysts.

The method is carried out as follows.

In a displacement reactor, a catalyst layer is placed between layers of inert filler (quartz packing). Dicyclopentadiene and hydrogen are dosed onto the catalyst at appropriate temperatures in two unidirectional flows from above (directly).

The most optimal hydrogen consumption is 550-1100 l/(l _cat ⋅h), since the use of less hydrogen leads to a decrease in the yield and conversion of the feedstock; a further increase in the excess of hydrogen is impractical, since it leads to a decrease in the contact time of the reaction mixture with the catalyst.

The most optimal weight feed rate of dicyclopentadiene is 1.73-3.46 h ^-1 . An increase in flow rate leads to a decrease in the conversion of starting materials, a decrease leads to a decrease in reactor productivity.

To obtain the catalyst, the γ-Al ₂ O ₃ carrier is impregnated with a 1 wt.% solution of complex copper compounds ([aqua-di-(furan-2-carboxylato-O)-di-(imidazole) copper(II) solvate with acetonitrile] or [ aqua-di-(furan-3-carboxylato-O)-di-(imidazole) copper(II)]) in distilled water or ethyl alcohol, filter the carrier and dry in air, followed by treatment with a 10 wt.% solution of sodium tetrahydroborate in distilled water at 60°C. The resulting catalyst is loaded into the reactor in wet form and dried from water in a stream of hydrogen immediately before the process.

The invention is illustrated by the following examples.

Example 1

[Aqua-di-(furan-3-carboxylato-O)-di-(imidazole) copper(II)] is used as a copper complex compound; ethanol is used as a solvent for impregnating the carrier. Molecular hydrogen is supplied to the catalyst at a flow rate of 1100 l/(l _cat ⋅h). Simultaneously with hydrogen, dicyclopentadiene is fed directly at a weight rate of 3.46 h ^-1 . Process temperature 150°C. Conversion of dicyclopentadiene 97%, selectivity for dihydrodicyclopentadiene 100%. The yield of dihydrodicyclopentadiene was 97%.

Example 2

Performed according to example 1 using copper (aqua-di-(furan-2-carboxylato-O)-di-(imidazole)copper(II) solvate with acetonitrile) as a complex compound], as a solvent for impregnating the carrier with distilled water, with hydrogen consumption is 550 l/(l _cat ⋅h) and the weight feed rate of dicyclopentadiene is 1.73 h ^-1 . Conversion of dicyclopentadiene 100%, selectivity for dihydrodicyclopentadiene 94%. The yield of dihydrodicyclopentadiene was 94%.

Example 3

Performed according to example 1 using copper complex compound [aqua-di-(furan-3-carboxylato-O)-di-(imidazole) copper(II)], as a solvent for impregnating the carrier with distilled water, with a hydrogen consumption of 550 l/(l _cat ⋅h) and the weight feed rate of dicyclopentadiene is 1.73 h ^-1 . Conversion of dicyclopentadiene is 100%, selectivity for dihydrodicyclopentadiene is 12%, selectivity for the product of complete hydrogenation - tetrahydrodicyclopentadiene is 88%. The yield of dihydrodicyclopentadiene was 12%.

Example 4

Performed according to example 1 using copper(II) aqua-di-(furan-2-carboxylato-O)-di-(imidazole)copper(II) solvate with acetonitrile as a complex compound], as a solvent for impregnation of the ethyl alcohol carrier, with hydrogen consumption is 550 l/(l _cat ⋅h) and the weight feed rate of dicyclopentadiene is 1.73 h ^-1 . Conversion of dicyclopentadiene 85%, selectivity for dihydrodicyclopentadiene 100%. The yield of dihydrodicyclopentadiene was 85%.

Thus, the method for producing dihydrodicyclopentadiene, which consists in the interaction of dicyclopentadiene with molecular hydrogen at a temperature of 150°C in a flow-type reactor in the presence of nanostructured copper particles immobilized on γ-Al ₂ O ₃ , obtained by chemical reduction of copper complex compounds, when hydrogen is supplied to the catalyst with flow rate of 550-1100 l/(l _cat ⋅h), and dicyclopentadiene - with a weight rate of 1.73-3.46 h ^-1 , provides increased selectivity of the process and increased yield of the reaction product.

Claims (1)

A method for producing dihydrodicyclopentadiene, which consists in the interaction of dicyclopentadiene with molecular hydrogen when heated in a flow-type reactor in the presence of a catalyst immobilized on aluminum oxide, characterized in that the process is carried out at a temperature of 150°C; nanostructured copper particles obtained by chemical reduction of complex copper compounds, its gamma modification is used as aluminum oxide, hydrogen is fed to the catalyst at a flow rate of 550-1100 l/(l _cat ⋅h), and dicyclopentadiene at a weight rate of 1.73-3.46 h ^-1 .