RU2359965C1 - Method for production of vinyl furfuryl ethers - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention is related to improved method for preparation of vinyl furfuryl and vinyl tetra hydrofurfuryl ethers by vinylation of appropriate alcohols by acetylene at atmospheric pressure of acetylene in medium of DMSO (dimethylsulfoxide) at the temperature of 70-100°C, for 3.5-6 hours, in presence of sodium hydroxide.

EFFECT: process simplification due to implementation of process at atmospheric pressure of acetylene and moderate temperature and increased yield of target product up to 90%.

Description

The invention relates to the field of organic chemistry, in particular to the improvement of a method for producing vinyl furfuryl and vinyl tetrahydrofurfuryl ethers based on the vinylation reaction of the corresponding alcohols with acetylene at atmospheric pressure.

Due to the depletion of oil reserves and environmental problems around the world, the role of obtaining chemical compounds from renewable raw materials capable of biodegradation is increasing. That is why, in recent decades, furfural derivatives have been widely used as versatile industrial solvents and precursors of chemical compounds.

Today, the largest volumes of furfural derivatives are in furfuryl and tetrahydrofurfuryl alcohols. The first is mainly used to obtain furan resins, adhesives, paints, the second is generally recognized as a "green" solvent for industrial use. Currently, these alcohols are widely used for the production of acrylates and epoxies, are included in the composition of environmentally friendly diesel and rocket fuels, and are used as components for creating effective special solvent mixtures.

Promising objects in terms of expanding the scope of application of these alcohols could be their vinyl esters, subject to the availability of the latter. Vinyl furfuryl ethers are highly reactive compounds, the basic building blocks (carriers of the furan core) to produce new derivatives of furan. On their basis, a variety of acetals, thioacetals, acylals (electrophilic addition of alcohols, diols, polyols, thiols, acids by vinyloxy group), heterocyclic compounds, polymers, etc. can be obtained.

A method for producing vinyl furfuryl and vinyl tetrahydrofurfuryl ethers of the general formula CH ₂ = CHOCH ₂ R, where

by vinylating the corresponding furfuryl alcohols with acetylene in the presence of a base, characterized in that the process is carried out at atmospheric pressure of acetylene in DMSO (dimethyl sulfoxide) at a temperature of 70-100 ° C, and sodium hydroxide is used as the base.

The advantage of this method is that it is implemented at atmospheric pressure of acetylene, moderate temperature (70-100 ° C), catalyzed by sodium hydroxide and allows to increase the yield of target vinyl esters (up to 91%) and, thus, reduce production costs.

A known method (Patent GB No. 580748) for the production of vinyl tetrahydrofurfuryl ether by the reaction of tetrahydrofurfuryl alcohol with acetylene, which is realized at atmospheric pressure in the environment of secondary or tertiary aromatic amines in the presence of potassium tetrahydrofurfurylate at a temperature of 170-190 ° C. The yield and purity of the target product, as well as its physicochemical characteristics, are not given in the patent. In addition, the disadvantages of this method include the harsh temperature conditions of vinyl, the need to use potassium metal and relatively expensive solvents (secondary or tertiary aromatic amines). It should also be noted that secondary amines can under these conditions react with acetylene, thereby reducing the selectivity of the process.

The known method (Rychkova A.G., Keller R.E. ZhOKH. 1961. T. 31. No. 6. S. 1849-1851; Uvarova N.I. Izv. SB AN SSSR, Ser. Chem. 1962. No. 1 P.78-82) obtaining vinyl furfuryl ether from furfuryl alcohol and acetylene under pressure (initial pressure at room temperature 16 atm) in water or dioxane at a temperature of 125-160 ° C in the presence of KOH. This method of synthesis of vinyl furfuryl ether is non-technological and ineffective. The reaction is accompanied by strong gumming, making it difficult to isolate and purify the target vinyl ester, the yield of which is 45-68%. At temperatures below 125 ° C, the vinylation reaction does not proceed.

The synthesis is described (Glukhovtsev V.G. et al. Izv. AN SSSR, Ser. Chem. 1968. No. 6. P.1382-1384; An V.V. et al. Chemistry of acetylene. Proceedings of the III All-Union Conference. M: Nauka, 1972. P.208-212) vinyltetrahydrofurfuryl ether in 73-81% yield. The reaction is carried out at elevated acetylene pressure and at a temperature of 160-180 ° C (i.e., in harsh non-technological conditions), using KOH as a catalyst.

A method is proposed for the synthesis of vinyl furfuryl ether with a yield of 80% reactions of furfuryl alcohol with acetylene in dimethyl sulfoxide (DMSO) in the presence of alkali metal glycoxides (MOH, where M = Na, K) (Oparina L.A. et al. ZhORKh. 2008. V. 44. Issue 1. S.122). The reaction is carried out at elevated acetylene pressure (autoclave, initial pressure at room temperature 10-12 atm) under relatively mild temperature conditions (75-85 ° C, 50 mol.% MOH, 1-2 hours).

Thus, the known methods for the synthesis of vinyl furfuryl ethers are not technologically advanced, primarily because the vinylation reactions of tetrahydrofurfuryl and furfuryl alcohols are realized under increased acetylene pressure, except for the method described in the British patent, but the latter is also not without drawbacks, as mentioned above.

We propose an improved method for producing vinyl esters of the furan series. The technical task of this invention is to simplify the technology for the production of vinyl esters by changing the process conditions, as well as increasing the yield and selectivity of the formation of the target products.

The problem is achieved in that acetylene is reacted with furfuryl alcohols at atmospheric pressure in a NaOH / DMSO superbasic catalytic medium at a temperature of 70-100 ° C, followed by isolation of the target product in a known manner: the resulting vinyl ether after dilution of the reaction mixture with water is extracted with diethyl ether and distilled .

The following examples illustrate the present invention.

Example 1. In a 250 ml reaction flask equipped with a reflux condenser, a thermometer, a magnetic stirrer and a bubbler for feeding acetylene, 100 ml of DMSO, 9.8 g (0.1 mol) of furfuryl alcohol, 2.0 g (0.05 mol) NaOH (50 mol%) were placed ), heated to 95 ° С and acetylene was passed at a rate of 2 l / h for 6 h. The progress of the reaction was monitored by ¹ N NMR spectroscopy. After the synthesis was completed, the reaction mass was diluted with water (100 ml), extraction was performed with diethyl ether (6 × 30 ml), the extract was washed with water (3 × 20 mL), dried Na ₂ CO _3, the solvent was removed by p Thorne evaporator. Distillation of the residue in vacuo gave 11.16 g (90%) of vinyl furfuryl ether, b.p. 39 ° C (8 mmHg),

n _D ²⁰ 1.4739. Found,%: C 67.70; H 6.57. C ₇ H ₈ O ₂ . Calculated,%: C 67.73; H, 6.50.

Example 2. In a 250-ml reaction flask equipped with a reflux condenser, a thermometer, a magnetic stirrer and a bubbler for feeding acetylene, 100 ml of DMSO, 10.21 g (0.1 mol) of tetrahydrofurfuryl alcohol, 4.0 g (0.1 mol) of NaOH (100 mol%) were placed ), heated to 90 ° С and acetylene was passed at a rate of 2 l / h for 3.5 h. After the synthesis was completed, the reaction mass was diluted with water (100 ml), extraction was performed with diethyl ether (6 × 30 ml), the extract was washed with water (3 × 20 ml), dried with Na ₂ CO ₃ , the solvent was removed on a rotary evaporator. Distillation of the residue in vacuo gave 11.76 g (91%) of 2-vinyl tetrahydrofurfuryl ether, b.p. 46 ° C (8 mmHg), n _D ²⁰ 1.4492. Found,%: C 65.44; H, 9.50. C ₇ H ₁₂ O ₂ . Calculated,%: C 65.60; H, 9.44.

Example 3. In a 250 ml reaction flask equipped with a reflux condenser, a thermometer, a magnetic stirrer and a bubbler for supplying acetylene, 100 ml of DMSO, 10.21 g (0.1 mol) of tetrahydrofurfuryl alcohol, 2.0 g (0.05 mol) NaOH (50 mol. %), heated to 85 ° C and acetylene was passed at a rate of 2 l / h for 5.5 h. After the synthesis was completed, the reaction mass was diluted with water (100 ml), extraction was performed with diethyl ether (6 × 30 ml), the extract was washed with water ( 3 × 20 ml), dried with Na ₂ CO ₃ , the solvent was removed on a rotary evaporator. Distillation of the residue in vacuo gave 9.74 g (76%) of 2-vinyl tetrahydrofurfuryl ether, b.p. 46 ° C (8 mmHg), n _D ²⁰ 1.4492. Found,%: C 65.58; H, 9.47. C ₇ H ₁₂ O ₂ . Calculated,%: C 65.60; H, 9.44.

Thus, it was shown that vinyl furfuryl ethers can be obtained in a much simpler way compared to previously known methods. Implementation of the proposed method on an industrial scale will allow, through the use of acetylene at atmospheric pressure, to fundamentally reduce the explosiveness of the technology, reduce the cost of the product by reducing the unit cost of raw materials (using cheaper sodium hydroxide compared to potassium hydroxide) and increase the yield of the target product almost to quantitative. The inventive process is highly selective, since in the process of its implementation no formation of by-products has been recorded.

Used Books

1. GB Patent No. 580748 (1946). Improvements in the manufacture of vinyl ethers. Jom M, Evans R. // C.A. 1947. Vol.41. P.2067g.

2. Rychkova A.G., Keller R.E. Synthesis of vinyl furfuryl ether, ethyl furfuryl and n-butyl furfuryl acetaldehyde acetals // Zhokh. 1961. Issue 31. S.1849-1851.

3. Uvarova N.I. Synthesis and some transformations of vinyl furfuryl ether // Izv. SB USSR Academy of Sciences, Ser. Chem. 1962. No. 1. S.78-82.

4. Glukhovtsev V.G., Nikishin G.I., Spector S.S., Zakharova S.V., Mamatov Yu.M., Popspirova N.M. Synthesis and properties of vinyl esters of the furan and tetrahydrofuran series // Izv. USSR Academy of Sciences, Ser. Chem. 1968. No. 6. S.1382-1384.

5. An V.V., Skvortsova G.G., An L.M., Mansurov Yu.A., Frolov Yu.L., Ratovsky G.V. Synthesis and spectral studies of simple and complex vinyl esters of the furan series // Chemistry of Acetylene. Proceedings of the III All-Union Conference. M .: Nauka, 1972.P.208-212.

6. Oparina L. A., Vysotskaya O. V., Stepanov A. V., Rodionova I. V., Myachina G. F., Gusarova N. K., Trofimov B. A. Nucleophilic addition to acetylenes in superbasic catalyst systems. XV *. Vinylation of 2-hydroxymethylfuran // Zhork. 2008.V. 44. Issue 1. S.122-125.

Claims (1)

A method of producing vinyl furfuryl and vinyl tetrahydrofurfuryl ethers by vinylating the corresponding alcohols with acetylene in the presence of a base, characterized in that the process is carried out at atmospheric pressure of acetylene in DMSO at a temperature of 70-100 ° C for 3.5-6 hours, and hydroxide is used as the base sodium.