RU2086528C1 - METHOD FOR PRODUCTION OF β-PHENYL ETHYL ETHER - Google Patents

Abstract

FIELD: organic synthesis, perfumery. SUBSTANCE: liquid phase hydrogenation of styrene is carried out at elevated temperature and at increased pressure in the presence of alkaline agent with the help of catalyst. Supported nickel catalyst being modified by palladium and comprising ferrum is used as mentioned above catalyst. Content of nickel in said catalyst is 0.08-0.5 mass %, ratio of Ni and Pd in it being 1:(1.5-0.2) and content of ferrum is not more 0.3 mass %. It is preferably to carry out said process in the presence of water, ratio styrene oxide and water is 85:15 respectively. Selectivity of conversion styrene oxide in b-phenyl ethyl ether is up to 98 %. EFFECT: improved efficiency. 4 cl

Description

 The invention relates to an improved method for producing β-phenylethyl alcohol, which can be used as a component of perfume compositions and fragrances.

 Among the many known methods for producing b-phenylethyl alcohol b-FES), the most effective is the liquid phase hydrogenation of styrene oxide (OS) on a suspended hydrogenation catalyst in the presence of an alkaline substance (such as sodium hydroxide, potassium, calcium, barium, sodium carbonate, potassium, calcium oxide , barium, etc.).

 A known method of producing b-FES by hydrogenation of the OS in an alcohol medium in the presence of a palladium catalyst.

 The main disadvantage of this method is the formation of a significant amount of by-products, in particular ethylbenzene (> 10 wt.), Which has an unpleasant odor and reduces the solubility of b-FES in water to such an extent that the latter does not pass the standard test for compliance with the "perfume" degree of purity.

 There is also a method for producing b-FES by hydrogenation of the OS, in which, in order to increase the yield and improve the quality of the b-FES, the process is conducted in water at a high OS: water ratio of 20-100: 100, using Raney Ni (Co) as a catalyst .

 It is desirable to add small amounts of alkaline substances to the reaction mixture (sodium or potassium hydroxide, sodium or potassium carbonate, calcium oxide or hydroxide, barium oxide or hydroxide) to a pH of preferably 7-8. This method claims the possibility of obtaining an "almost quantitative yield" of b-FES, however, many researchers who tried to reproduce this method showed that in reality the yield does not exceed 85%, a lot of ethylbenzene is formed.

To achieve high selectivity for b-FES during hydrogenation of the OS in water in the presence of Raney Ni, it was proposed to carry out the hydrogenation process at low temperatures (<10 ^° C) and in a concentrated emulsion (1-30 parts by weight of water per 100 parts by weight). OS).

 With all the advantages of this method (the yield of b-FES is up to 95% relatively few impurities) it is difficult to put into practice because of the need to maintain a low temperature for a sufficiently long reaction time (up to 12 hours).

 In the known methods used individual catalysts, mainly Ni (Co) Raney or catalysts based on platinum group metals. Each of them individually does not allow one to achieve high selectivity in the process of hydrogenation of the OS to b-FES and to avoid undesirable impurities (to varying degrees characteristic of different catalysts), such as, for example, ethylbenzene. phenylacetaldehyde and others

 These problems can be solved by using a mixture of two supported palladium catalysts and Raney Ni (or Co). In the closest to the proposed known method, hydrogenation of the OS is carried out in water (5-20% of the OS) in the presence of a mixture of a palladium (1-5% Pd / C) catalyst and Raney Ni in a wide range of ratios: 1-10 wt.h. Nickel per 100 parts by weight OS and 0.001-0.1 parts by weight palladium (metal) per 100 parts by weight OS

 In this case, as in the above methods, small amounts of alkaline substances can be used in the process to suppress the isomerization of OS into phenylacetaldehyde.

To obtain successful results, the process of hydrogenation of the OS is carried out in two stages: at the first stage, relatively low temperature and pressure of hydrogen (10-60 ^o C and 3.5 at) are used, then, when the absorption of hydrogen stops under the conditions of the first stage, the temperature and pressure are raised (90-140 ^o C and approximately 15 at). The output of perfumery pure b-FES ≅96.7%
The disadvantages of this method are:
the need to use a mechanical mixture of two different catalysts: palladium supported (preferably carbon) and pyrophoric Ni Raney, which complicates the technology, makes it difficult to reuse the catalyst (they behave differently in the second cycle), and the subsequent disposal of precious metal (palladium when mixing the catalysts it is diluted with nickel, the amount of which is 10-10 ⁵ times the amount of palladium);
the need for a two-stage hydrogenation process.

 It should be noted that, despite the declared wide limits of the mass ratios of palladium: OC and nickel: OC, in reality only the average ratios are confirmed, the minimum of which are: Pd: OC ≃ 0.004: 100, Ni: OC; 4: 100, which is four times higher than the minimum stated in this method.

.The activity of the catalysts in the known method, calculated according to the examples, is

.

 The purpose of the invention is the simplification and increase the efficiency of the process of obtaining β-FES.

 This goal is achieved by the fact that when liquid-phase hydrogenation of the OS in the presence of an alkaline substance at elevated temperature and pressure, a supported nickel catalyst modified with palladium and containing iron is used. The nickel content in the catalyst is 0.08-0.5 wt. with a ratio of nickel: palladium equal to 1: (1.5-0.2), and the iron content is not more than 0.3 wt. It is preferable to carry out the process in the presence of water at a volume ratio of OS: water equal to 85:15.

Hydrogenation is carried out under fairly mild conditions (≅80 ^o C and ≅15 ati), small additives of hydroxides and carbonates of potassium, sodium, ammonium are used as alkaline substances, and known carriers with a developed common surface (S _beats ) of at least 250 are used as a carrier m ² / g.

) в широком интервале концентраций ОС как в воде, так и в низших алифатических спиртах и в водно-спиртовых смесях и обеспечивает высокую (до 98%) селективность превращения ОС в β-ФЭС, что позволяет получить целевой продукт парфюмерного качества при соотношениях (в мас.ч.) как никеля, так и палладия к ОС, равных 0,001-0,002:100.The proposed catalyst is highly active (

) in a wide range of OS concentrations both in water and in lower aliphatic alcohols and in water-alcohol mixtures and provides a high (up to 98%) selectivity for the conversion of OS into β-FES, which allows one to obtain the target perfume-quality product at ratios (in wt. .h.) of both nickel and palladium to OS equal to 0.001-0.002: 100.

 The high activity of the proposed catalyst is due not only to its composition, but also to the fact that palladium is deposited on carriers from solutions of its chlorohydroxocomplexes (CGC Pd) obtained by alkaline hydrolysis of palladium chloride with a mass ratio of alkali metal hydroxide and palladium equal to 0.25-0.65 :1.

 The invention is illustrated by the following examples.

 A. Preparation of the catalyst.

Example 1a The catalyst is prepared in a laboratory setup, which is a three-necked round-bottom flask with a capacity of 0.5 dm ³ , equipped with a stirrer, thermometer, dropping funnel and a refrigerator, heated with a mantle heater, as well as a Bunsen flask with a funnel for filtering under vacuum.

In a three-necked flask, 100 cm ^{3 of} distilled water and 10 g (calculated on dry weight) of coal OUB (S _beats = 700 m ² / g) are loaded with stirring. The suspension is heated to 60-70 ^o C and dosed to it with stirring, first 1 N sodium hydroxide solution to establish a pH of 10.0, and then a solution of nickel sulfate (0.047 g NiSO ₄ • 7H ₂ O in 1.6 cm ^{3 of} distilled water) . The suspension is maintained at 60-70 ^o C and stirring for 30 minutes, cooled to approximately 50 ^o C, after which a solution of HCA Pd is dosed.

A solution of HCA Pd is prepared by dissolving 0.021 g of palladium chloride (59.5% palladium) in an acidified aqueous solution of sodium chloride (0.01 g of NaCl, 0.65 cm ^{3 of} distilled water and approximately 0.001 cm ^{3 of} hydrochloric acid) when heated to 60- 70 ^o C and stirring, after which the solution is cooled to 30-40 ^o C and add a 0.5 N solution of potassium hydroxide to a mass ratio of KOH: Pd = 0.5: 1.

After dosing the HCA Pd solution, the suspension is kept for 15 minutes, then a solution of ferrous sulfate (0.025 g of FeSO ₄ • 7H ₂ O in 6.5 cm ^{3 of} distilled water) is metered into it, the pH is adjusted to 8.0 with 1% sodium carbonate and maintain the suspension for 30 minutes, then filter under vacuum on a Buchner funnel and wash the precipitate with distilled water until there are no chlorine ions in the wash water. According to the analysis by atomic absorption method, the catalyst contains (based on the weight of the dry product), wt. 0.08 nickel, 0.12 palladium and 0.11 iron.

Example 2a The catalyst is prepared in an installation consisting of an enameled synthesis reactor with a capacity of 160 dm ³ , equipped with a heating jacket, stirrer and refrigerator) with a suction filter, and a glass dispenser tank.

With stirring, 80-90 dm ^{3 of} distilled water and 10 kg (in terms of dry weight) of active cellulignin ACB-O, (S _beats -630 m ² / g), are loaded. A solution of iron chloride obtained by dissolving 145.0 g of FeCl • 6H ₂ O 1.5 dm ^{3 of} distilled water is dosed to the suspension over approximately 20 minutes, then the pH is adjusted to 8.0 with a 1 N sodium hydroxide solution, and after heating (up to 60 - 70 ^o ) to a pH of 10.0. A solution of nickel (247.5 g of Ni (NO ₃ ) ₂ · 6H ₂ O in 2 dm ^{3 of} distilled water) is dosed to the suspension for approximately 10 minutes, followed by a 30-minute exposure, after which the contents are cooled to 50 ^° C and slowly dispense a solution of CHC Pd.

A solution of CHC Pd is prepared in a flask with a stirrer with a capacity of 1.0 dm ³ , dissolving at 60-70 ^o C 21.25 g of palladium chloride in 625 cm ^{3 of} distilled water in the presence of 14 g of sodium chloride and 15 cm ^{3 of} hydrochloric acid. The resulting solution was cooled to 30-40 ^o C and hydrolyzed with 1 N sodium hydroxide solution to a mass ratio of NaOH: Pd0,25.

After dosing the HCA Pd solution, the suspension was incubated for 1 h at 50 ^° C, then the catalyst paste was filtered and washed to the absence of Cl ^- ions in the wash water. The finished catalyst is a paste with a moisture content of 40-50% containing (based on the weight of the dry product), wt. 0.5 nickel, 0.1 palladium, 0.3 iron.

Example 3a The catalyst is prepared in a pilot plant consisting of a catalyst synthesis reactor with a capacity of 6.3 m ³ , a reactor for preparing a CHC Pd solution with a capacity of 0.63 m ³ , reactors for preparing an alkali solution with a capacity of 0.4 m ³ and a nickel salt solution with a capacity of 0.1 m ³ , and for filtering and washing the catalyst filter press type FPAKM.

Desalted water in an amount of 3.5-4.0 m ^{3 is} terminated in a catalyst synthesis reactor from a mernik and approximately 1000 kg of OUB coal (S _beats = 700 m ² / g) with a moisture content of approximately 50% and an iron content of 0.26 wt are loaded with stirring . The coal suspension is heated to 60-70 ^o C, then a 1 N aqueous solution of Na hydroxide (180-200 dm ³ ) is dosed to establish a pH≥10, after which a solution of nickel chloride (4 kg NiCl ₂ • 6H ₂ O 60-80 dm ³ demineralized water) and hold for 40 minutes at 60-70 ^o C. Then the contents of the reactor are cooled to 30-40 ^o C and meter the solution of CGC Pd for 1 hour

A solution of CHC Pd is prepared by loading 100-120 dm ³ desalted water, 130-140 cm ³ hydrochloric acid, 1.7 kg of palladium chloride and 0.6 kg of sodium chloride into the reactor with stirring. The mixture is heated to 60-70 ^o and maintained at this temperature and stirring until the palladium salt is completely dissolved. The solution is cooled to 30-40 ^o C, after which a 1 N sodium hydroxide solution is slowly dosed to a mass ratio of NaOH: Pd = 0.5: 1.

 After a dosage of HCA Pd, the suspension is kept in the synthesis reactor for about 1 hour, then filtered by PFACM and the precipitate is washed with ten times the amount of water.

 The finished catalyst is a paste with a moisture content of 40-50% containing (according to analysis), wt. 0.22 nickel, 0.18 palladium and 0.25 iron based on the weight of the dry product.

 Catalysts of a different composition (with active component ratios meeting the proposed limits) are prepared according to the methods of Examples 1a-3a with the charges necessary to obtain the desired catalyst composition.

 B. Obtaining b-FES.

 In the examples of synthesis of b-FES below by hydrogenation of the OS, two types of plants are used.

 Type I-laboratory kinetic hydrogenation unit at constant temperature and pressure of hydrogen.

The reactor is a glass ampoule with a volume of 45-55 cm ³ , sealed in a steel thermostatic casing of the shaking device, connected through a valve system with hydrogen and nitrogen cylinders, a buffer tank and a measuring system. The system is heated using a thermostat. Coolants glycerin or water, the temperature is regulated by a contact thermometer. The presence of a buffer tank in the system ensures that the process is conducted at almost constant pressure.

 After the end of the process, hydrogen is replaced in the system with nitrogen, the catalyst is separated from the reaction mass by "hot" filtration. The reaction mass is analyzed by gas liquid chromatography (GLC).

Type II bench installation of periodic action, including an autoclave with a capacity of 1 dm ³ with a jacket for supplying coolant, a filter for separating the catalyst, a settling tank for the separation of water emulsions of b-FES.

 The autoclave is connected via a valve system to hydrogen and nitrogen cylinders, a buffer tank and an automatic measuring system.

 Hydrogenation catalysts, which are, after separation of the catalyst, solutions or emulsions of b-FES, are directed to rectification to separate the solvent (diluent) and the isolation of the pure target product of b-FES.

 Example 1b Hydrogenation is carried out in a type I installation.

,
селективность конверсии ОС в β-ФЭС (по данным ГЖХ) 96,9%
Пример 2б. Гидрирование проводят на установке типа I.A solution of 0.01 g Na ₂ CO ³ in 7 cm ^{3 of} ethyl alcohol, 7.5 cm ^{3 of} pure styrene oxide and 0.025 g of catalyst (in terms of dry) prepared according to Example 1a and containing, by weight, is loaded into the ampoule. 0.08 nickel, 0.12 palladium and 0.11 iron. Hydrogenation in isothermal mode (70 ^o C) and at a constant hydrogen pressure of 15 atm is completed in 1 h 40 min quantitative (from theory) absorption of hydrogen. The activity of the catalyst was

,
the selectivity of the conversion of OS in β-FES (according to GLC) 96.9%
Example 2b Hydrogenation is carried out in a type I installation.

,
селективность конверсии ОС в β-ФЭС (по данным ГЖХ) 96,7%
Пример 3б. Гидрирование проводят на установке типа II.Download: 0.01 g of NaHCO ₃ , 5 cm ^{3 of an} aqueous solution of isopropanol (50:50), 10 cm ^{3 of} pure styrene oxide and 0.03 g of catalyst (in terms of dry), prepared according to example 2a and containing, by weight. 0.5 nickel, 0.1 palladium and 0.3 iron. Hydrogenation in isothermal mode (65 ^o C) and a constant hydrogen pressure of 5 atm is completed in 1 h 25 min quantitative (from theory) absorption of hydrogen. The activity of the catalyst was

,
the selectivity of the conversion of OS in β-FES (according to GLC) 96.7%
Example 3b Hydrogenation is carried out on a type II plant.

), затем после получасовой выдержки при постоянном перемешивании, водород из автоклава вытесняют азотом и давлением азота (1,5-2 ат) передавливают катализат через фильтр в приемник, затем в отстойник. После расслоения эмульсии нижний водный слой, содержащий до 2% β-ФЭС, отделяется он может быть повторно использован (вместо воды) в следующих операциях гидрирования ОС. Верхний слой, содержащий до 7% воды, направляют на ректификацию. Селективность конверсии ОС в b-ФЭС составляет 98% После ректификации показатель преломления целевого продукта n $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ = 1,532 d²⁰ 1,024, массовая доля β-ФЭС=99,6% органолептическая оценка в баллах 4,9.0.85 g of NaOH is dissolved in 90 cm ³ H ₂ O, 2.5 g of the catalyst obtained in example 3a and containing, by weight, are suspended in the resulting solution. 0.22 nickel, 0.18 palladium and 0.25 iron. The resulting suspension of the catalyst is loaded into the autoclave, 510 g of styrene oxide, the air is displaced with nitrogen, then (after purging with hydrogen) the autoclave is filled with hydrogen at a pressure of 10 atm, and, by increasing the temperature by supplying the coolant to the jacket to 45 ^° C, the mixer is switched on. Due to the heat of the reaction, the temperature in the autoclave rises by the end of the process to 80 ^o C. The absorption of hydrogen is completed after 1.5 hours (the activity of the catalyst was

), then after a half-hour exposure with constant stirring, the hydrogen is displaced from the autoclave with nitrogen and the pressure of nitrogen (1.5-2 at) is transferred through the filter to the receiver, then to the sump. After separation of the emulsion, the lower aqueous layer containing up to 2% β-FES is separated, it can be reused (instead of water) in the following OS hydrogenation operations. The top layer containing up to 7% water is sent for rectification. The selectivity of the conversion of OS in b-FES is 98%. After rectification, the refractive index of the target product n $\genfrac{}{}{0ex}{}{\text{twenty}}{\text{D}}$ = 1.532 d ²⁰ 1.024, mass fraction of β-FES = 99.6% organoleptic score in points of 4.9.

 Example 4b. Hydrogenation is carried out on a type II plant.

Loading: 0.068 g of KOH, 90 cm ³ H ₂ O, 10 cm ³ ethanol, 520 g styrene oxide, 3.0 g catalyst, composition, wt. 0.16 nickel, 0.1 palladium and 0.16 iron, prepared according to the method of example 1a, but using calculated amounts of iron chlorides (2 ⁺ ) and nickel (at the stage of adsorption of salts of the precursors of these active components), a mixture of sodium carbonate and bicarbonate (at the stage of hydrolysis of the iron salt) and with the ratio of KOH: Pd = 0.45 (at the stage of synthesis of CGC Pd).

). Селективность конверсии ОС в β-ФЭС составила 97,1%
После ректификации показатель преломления целевого продукта 1,531,d²⁰ 1,023, массовая доля b-ФЭС99,5% органолептическая оценка в баллах 4,7.The initial temperature in the autoclave is 40 ^o C, the final is 75 ^o C, the pressure of hydrogen is 15 atm, the time for completion of hydrogen absorption is 65 min (catalyst activity

) The selectivity of the conversion of OS in β-FES was 97.1%
After rectification, the refractive index of the target product is 1.531, d ²⁰ 1.023, the mass fraction of b-FES is 99.5%, an organoleptic score of 4.7.

The proposed method for producing b-phenylethyl alcohol has the following advantages compared to the prototype:
the process is carried out in one stage with high (up to 98%) selectivity for the conversion of styrene oxide to b-FES;
to obtain the target product of perfumery quality, a ratio of nickel (and palladium) to styrene oxide equal to 0.001-0.002: 100;
the use (in prototype) of a mixture of catalysts (Raney Ni and Pd on a carrier) complicates the reuse and disposal of such a catalyst, while the proposed method uses a single catalyst containing both active metals (Ni and Pd) necessary to achieve the goal ;
the catalyst according to the proposed method does not have the disadvantages inherent in Raney Ni) such as, for example, pyrophoricity and the need for special processing;
according to the proposed method, it is possible to reuse both the catalyst and the water mother liquor after separation of the organic layer.

Claims (3)

 1. The method of producing β-phenylethyl alcohol by liquid-phase hydrogenation of styrene oxide in the presence of a catalytic system containing nickel and palladium, and an alkaline additive at elevated temperature and pressure, characterized in that a supported nickel catalyst modified with palladium and containing iron is used as a catalytic system .  2. The method according to claim 1, characterized in that the nickel content in the catalyst is 0.08 to 0.5 wt. when the ratio of Nickel: palladium 1 1.5 0.2, and the iron content in the catalyst is not more than 0.3 wt.  3. The method according to claim 1, characterized in that the hydrogenation is carried out in the presence of water at a ratio of styrene oxide: water 85 to 15.