ES2939559B2 - Synthesis of trans 2,4,7,9-tetramethyldecen-4,7-diol by catalytic semi-hydrogenation with molecular hydrogen - Google Patents

Description

DESCRIPTION

Synthesis of trans 2.4.7.9-tetramethyldecen-4.7-diol by catalytic semi-hydrogenation with molecular hydrogen

field of invention

The present invention describes a highly selective procedure for the synthesis of trans 2.4.7.9-tetramethyldecen-4,7-diol through the hydrogenation of its acetylenic precursor, 2.4.7.9-tetramethyldecin-4,7-diol (known as TMDD for its acronym in English) with hydrogen gas and a solid catalyst, for the formulation and use as a lubricant, surfactant, antifoaming agent and wetting agent for applications of industrial interest such as, and not limited to, the manufacture of polymers, coatings, inks, lubricants and food processing.

BACKGROUND OF THE INVENTION

Surfactants and antifoam agents are a key element in the management of multiphase mixtures. These compounds concentrate at the interface of multiphase systems and perform various functions, such as increasing the solubility and dispersion of the compounds in the mixture, in addition to controlling other properties of the system.

During the 1950s and 1960s, alkylbenzenesulfanates (ABS) were the monomeric synthetic surfactants that dominated the market, before being displaced in the 1970s and 1980s by linear alkylbenzenesulfanates (LABS). ), which alleviated the degradation problems in water treatment suffered by their predecessors. Since then, advances in different industrial sectors, changes in the market and the implementation of new regulations have driven the emergence of new surfactants. Among them, “Gemini” surfactants constitute a promising new class due to their versatility and effectiveness. These dimeric surfactants are inherently more efficient than their monomeric predecessors, generally possessing twice as many hydrophobic and hydrophilic groups per molecule. Commonly, the hydrophilic groups are located at the ends of the spacer group, which forms the central axis of the molecule, and from which the hydrophobic tails of the surfactant emerge. Due to this specific structure, their intermolecular forces are well compensated, giving them good antifoaming properties. (Galgoci, EC, Chan, SY and Yacoub, K. (2006) 'Innovative, Gemini-Type Molecular Defoamer Technology for Improved Coating Aesthetics', JCT Research, 3(1), pp. 77-85.)

Despite being compounds already known in the 70s, it has been three decades later that research into the role of their structure in their function as surfactants has been encouraged, more specifically, in expanding the structural diversity of “Gemini” surfactants. (Menger, FM, Keiper, JS and Azov, V. (2000) 'Gemini surfactants with acetylenic spacers', Langmuir, 16(5), pp. 2062-2067. doi: 10.1021/la9910576). Specifically, the acetylenic compound “gemini” 2,4,7,9-tetramethyldecin-4,7-diol is known for its antifoaming activity, among others, and in recent years the activity of its alkene and alkane derivatives has been studied. (EP0940169A1), observing a better solubility in water and, therefore, a greater potential of applicability for its semi-hydrogenated derivative the trans alkene 2,4,7,9-tetramethyldecen-4.7- diol with respect to the corresponding cis 2,4, 7,9-tetramethyldecen-4,7-diol. Unlike acetylene, an ethylene spacer provides greater flexibility to the compound, which provides different possible conformations at the interface. This new chemical structure provides new Theological properties and its liquid state at room temperature, which together with its relative high solubility in water, gives trans 2,4,7,9-tetramethyldecen-4,7-diol a vehicle advantage compared to to its acetylenic and cis alkene equivalent, which together make this compound an attractive alternative to TMDD.

However, the synthesis of the aforementioned trans compound from 2,4,7,9-tetramethyldecyn-4,7-diol is severely impeded under typical reaction conditions and the yields are always less than 10% (Amador et al., Heterocycles 67 (2), 705-720, 2006; document US2011004028A1), even with hydrides not from molecular hydrogen such as copper hydrides (N. Cox et al., Tetrahedron 70(27-28) 4219-4231, 2014) or derivatives of hydrazine (document CN105439817A). In fact, to date, there are only specific synthesis procedures for the aforementioned cis alkene and not for the trans one, and these methods use as reducing agents a combination of polysiloxanes and potassium tert-butoxide in stoichiometric quantities (Aaron M Whittaker, Gojko Lalic , Org. Lett., 15(5), 1112-1115, 2013; NickCox, Hester Dang, Aaron M. Whittaker, Gojko Lalic. Tetrahedron, 70(27-28), 4219 4231; 2014), with expensive and unrecoverable homogeneous catalysts.

The present invention provides the selective preparation of trans 2,4,7,9-tetramethyldecen-4,7-diol by selective semihydrogenation of 2,4,7,9-tetramethyldecin-4,7-diol with palladium catalysts and molecular hydrogen . The system of the present patent represents the first efficient synthesis described for the aforementioned trans isomer, where hydrogen is used as a 100% efficient reducing agent and a recoverable solid catalyst, without residues. Furthermore, the process can be implemented continuously.

DESCRIPTION OF THE INVENTION

The present invention describes a procedure for the highly selective synthesis of trans 2,4,7,9-tetramethyldecen-4,7-diol through the partial hydrogenation of its acetylenic precursor, 2,4,7,9-tetramethyldecin-4, 7-diol (known as TMDD) with hydrogen gas and a solid catalyst, for the formulation and use as a lubricant, surfactant, antifoaming agent and wetting agent for applications of industrial interest such as, but not limited to, manufacturing of polymers, coatings and linings, inks, lubricants and food processing-

This procedure includes the following stages:

a) contacting the acetylenic diol 2,4,7,9-tetramethyldecin-4,7-diol (TMDD) (1) with a palladium-containing catalyst,

b) add hydrogen (H ² ) to the mixture obtained in step a) until obtaining at least 3 bars of pressure,

c) heat the mixture obtained in step b) to a temperature between 50 °C and 1200C.

The process preferably includes an additional step d) of recovering the reaction product from the catalyst.

The reaction procedure gives rise to a mixture of the isomer trans-2,4,7,9-tetramethyldecen-4,7-diol (3) and the alkene cis-2,4,7,9-tetramethyldecen-4,7 -diol (2), always obtaining the trans isomer in a majority.

According to a particular embodiment of the present invention, the amount of acetylenic diol (1) that the initial mixture can contain in step a) is in amounts between 10%-99% by weight, preferably between 20%-99%.

Step a) can be carried out in the presence or absence of solvent. If a solvent is used, it is preferably selected from the list that includes: ethanol, heptane, isopropanol, toluene, water and combinations thereof.

If a solvent is used, the amount of this with respect to the acetylenic diol (1) is preferably between 1 and 10 times by weight.

According to another particular embodiment, the molar ratio of acetylenic diol (1) to catalyst is between 10,000 and 10, preferably between 1,000 and 100.

In a preferred embodiment, the Pd contained in the catalyst is in the form of nanoparticles, preferably between 1 and 50 nanometers. Furthermore, the palladium can be supported or intimately mixed with compatible solids, a compatible solid being defined as one that supports and/or activates the palladium for the reaction, among which we can mention, by way of example, inorganic oxides, carbonates, activated carbon, zeolites, MOFs and polymers as a support, or lead as an additive. In a more preferred embodiment, the catalysts selected from the list comprising: Pd on CaCC> ³ , “Lindlar” catalyst, Pd/TiS colloidal catalyst

The Lindlar catalyst, as is well known to those skilled in the art, is a heterogeneous catalyst formed by palladium precipitated in calcium carbonate and treated with lead (II) acetate or quinoline, a procedure also known as poisoning of the catalyst whose objective is deactivate some active PD positions.

The amount of palladium supported on the catalyst can preferably range from 0.01% to 10% by weight.

According to a particular embodiment of the present invention, the amount of hydrogen that can be used is from 3 to 150 equivalents (moles), more preferably between 3 and 100 equivalents and, even more preferably, between 10 and 100 equivalents with respect to the acetylenic diol (1).

According to a particular embodiment of the present invention, the H ² added in step b) is at pressures between 3 and 20 bars, preferably 5 to 15 bars,).

According to a particular embodiment of the present invention, the heating of step c) is carried out at a temperature between 60 and 800C.

The heating time of step c) can vary between 5 min and 48 h, preferably between 1 and 10 hours.

According to another particular embodiment of the present invention, reaction steps a)-c) can be carried out in a batch reactor, or in a flow reactor.

In a preferred embodiment, step d) is carried out by separation of the solid catalyst by filtration or centrifugation, and the separation of (2) and (3) by selective extraction in organic solvent (for example: ethyl acetate, dichloromethane hexane )/water or column chromatographic separation.

The present invention also refers to the mixture or composition obtained according to the procedure described above.

Then, the present invention relates in a second aspect to a composition comprising a mixture of trans-2,4,7,9-tetramethyldecen-4,7-diol (3) and cis-2,4,7,9- tetramethyldecen-4,7-diol (2), in molar ratios (2):(3) less than 1, preferably, the ratios are between (2):(3) are between 1:1.1 and 1:3; more preferably between 1:1.3 and 1:2.5.

In a preferred embodiment, the purity of the mixture of compound (2) and (3) is between 25% and 100% (by weight).

Furthermore, the present invention also refers to the use of the product obtained according to the process of the present invention that comprises a mixture of compounds (2) and (3), with (3) being the majority. Preferably, a last aspect of the invention refers to the use of the composition obtained according to the procedure described in the first aspect of the invention or the composition described in the second aspect of the invention as a lubricant, surfactant, antifoam and/or or humectant and, more particularly, for the formulation and manufacturing of polymers, coatings and linings, inks, lubricants and food processing. Compound (3) is more soluble in water, so it can be better formulated and applied in most water-based industrial applications, much cheaper and environmentally friendly. Therefore, the mixture obtained directly by the process of the invention, with a majority in the compound (3), is advantageous with respect to the mixtures obtained in the procedures of the state of the art that lead mainly to the cis isomer (2). These state-of-the-art mixtures require the separation of both compounds for the subsequent use of the minor compound (3).

Throughout the description and claims the word "comprises" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will emerge partly from the description and partly from the practice of the invention.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1: Scheme of the catalytic pathway for the semi-hydrogenation of 2,4,7,9-tetramethyldecen-4,7-diol (1) to trans-2,4,7,9-tetramethyldecen-4,7-diol (3) and cis-2,4,7,9-tetramethyldecen-4,7-diol (2). The product 2,4,7,9-tetramethyldecane-4,7-diol (4) is obtained in very low quantities or not at all.

EXAMPLES

Non-limiting examples of the present invention are detailed below:

Example 1: Reaction procedure in a batch reactor without solvent and Lindlar catalyst (5% by weight Pd).

A batch reactor was charged with 7 g of pure 2,4,7,9-tetramethyldecyn-4,7-diol (1) containing 1% by weight of Pd (0.5 mol%) with respect to the diol in a catalyst. from Lindlar. Subsequently, the reactor was pressurized to 10 bars with 20 equivalents of hydrogen and the temperature was raised to 65 0C. The reaction was stopped after 12 h and the product was recovered.

The reaction was monitored with a GC equipment with FID detector. The conversion of (1) obtained was 99.5% and the selectivity to ethyl diol was 99.9%, with a molar ratio of 1:1.3 between (2) and (3). The physical properties of the reaction mixture obtained and filtered are detailed in Table 1.

Table 1: Physical properties of the reaction product mixture.

Example 2: Reaction procedure in a batch reactor in ethanol with different palladium catalysts.

Three batch reactors were charged with 0.1 g of pure 2,4,7,9-tetramethyldecin-4,7-diol (1) containing 0.001%, 0.04% and 0.01% by weight of Pd with respect to diol on a palladium catalyst supported on CaCÜ ³ (0.1% Pd by weight), a “Lindlar” catalyst (5% Pd by weight), and a colloidal Pd catalyst on titanium silicate (0. 5% Pd by weight), respectively (the Lindlar catalyst was purchased commercially from Aldrich, the colloidal Pd/TiS catalyst was purchased commercially from BASF and the Pd catalyst on CaCÜ ³ was prepared by the procedure indicated below). 0.2 mL of ethanol was added. Subsequently, the reactors were pressurized to 3 bars with 3 equivalents of hydrogen and the temperature was raised to 600C. The reaction was stopped after 48 h and the product was recovered.

The reaction was monitored with a GC device with FID detector, and a GC-MS device with FID detector and quadrupole ion trap. The conversions and selectivities are shown in Table 2.

Table 2: Conversions and selectivities of the reactions. The ratio of (3) to (2) is >1 in all cases. The material balance is completed by considering the hydrogenolysis byproducts of one or both alcoholic groups.

As can be seen in Table 2, the Pd catalyst on CaCÜ ³ in solution and the Pd/TiS colloidal catalyst are superior to the classic Lindlar catalyst, obtaining in all cases good selectivity towards the desired compound (3).

The Pd catalyst on CaCÜ ³ was prepared from an ethanol solution saturated with Pd2(dba) ₃ and C 02, also containing triethylamine and calcium chloride. Carbon dioxide, together with the calcium salt, form calcium carbonate in situ, the precipitation of which is prevented by the base, which stops the nucleation and in turn destabilizes the palladium precursor, thus generating subnanometer palladium aggregations, contained in the calcium carbonate matrix in suspension.

Example 3: Reaction procedure in a batch reactor with different solvents.

Six batch reactors were loaded into the same autoclave with 1 g of pure 2,4,7,9-tetramethyldecin-4,7-diol (1) containing 1% by weight of Pd with respect to the diol in a catalyst of “ Lindlar” (5% Pd by weight). Next, 4 ml of ethanol, heptane, isopropanol, toluene and water were added to each reactor, leaving the first one without solvent. Subsequently, the autoclave was pressurized to 10 bars with 20 equivalents of hydrogen and the temperature was raised to 65 0C. The reaction was stopped after 24 h and the product was recovered. The reaction was monitored with a GC equipment with FID detector.

Table 3: Conversions and selectivities of the reactions.

Claims (15)

1. Procedure for obtaining trans 2,4,7,9-tetramethyldecen-4,7-diol characterized in that it comprises the following steps: a) contacting the acetylenic diol 2,4,7,9-tetramethyldecin-4,7-diol (1) with a catalyst containing palladium, b) add hydrogen to the mixture obtained in step a) until obtaining at least 3 bars of pressure, and c) heat the mixture obtained in step b) to a temperature between 50 °C and 120 °C. 2. Procedure according to claim 1, where the amount of acetylenic diol (1) contained in the initial mixture in step a) is between 10%-99% by weight. 3. Procedure, according to any of the preceding claims, where step a) is carried out in the presence or absence of solvent. 4. Procedure, according to claim 3, wherein step a) is carried out in the presence of a solvent selected from the list that includes: ethanol, heptane, isopropanol, toluene, water and combinations thereof. 5. Procedure, according to any of the preceding claims, wherein the amount of hydrogen used is from 3 to 150 equivalents with respect to the acetylenic diol (1). 6. Procedure, according to any of the preceding claims, wherein the molar ratio of acetylenic diol (1) to catalyst is between 10,000 and 10. 7. Procedure according to any of the preceding claims, wherein the palladium contained in the catalyst is nanoparticulate, with a particle size between 1 and 50 nanometers. 8. Procedure according to any of the preceding claims, wherein the palladium catalyst used is selected from the list that includes: Pd on CaCO ³ , “Lindlar” catalyst or Pd/TiS colloidal catalyst. 9. Procedure, according to any of the previous claims, where the amount of palladium in the catalyst is between 0.01% and 10% by weight. 10. Procedure, according to any of the previous claims, where the H ² added in step b) is at pressures between 3 and 20 bars. 11. Procedure according to any of the preceding claims, wherein the reaction temperature of step (c) is between 60 and 80 °C. 12. Procedure, according to any of the previous claims, where the heating time of step c) is between 5 min and 48 h. 13. Procedure, according to any of the preceding claims, comprising an additional stage d) of separating the catalyst. 14. Procedure, according to any of the previous claims, characterized in that steps a)-c) are carried out in a batch reactor. 15. Method according to any of claims 1 to 13, characterized in that steps a)-c) are carried out in a flow reactor.