RU2559319C1 - Method of obtaining 1,3-bis-o-(polyfluoralkyl)glycerol - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of obtaining 1,3-bis-O-(polyfluoralkyl)glycerol of the general formula:

, where at X=H n=2,4,6; at X=F n=1-8, which is applied as surface-active substances and semi-products for organic synthesis. The method consists in the interaction of fluorinated alcohol of the general formula X(CF₂)_nCH₂OH at X=H n=2,4,6; at X=F n=1-8 with epichlorohydrin in an alkaline medium with heating. The process is carried out with the molar ratio of fluorinated alcohol:epichlorhydrin:alkali equal 3:1:2, at a temperature of 70-75°C, with the separation of the target product being realised by precipitation with a mineral acid, separation of the organic layer and its distillation in vacuum.

EFFECT: method makes it possible to obtain target products with high output with the application of a simple technology.

2 dwg, 6 ex

Description

The invention relates to the chemistry of organofluorine compounds, and in particular to a method for producing fluorine-containing secondary alcohols - glycerol derivatives, which are used as surfactants and intermediates for organic synthesis.

Surfactants based on polyfluorinated alcohols are characterized by high performance characteristics: their addition to aqueous and organic solutions leads to a decrease in surface tension, they are characterized by a low coefficient of friction, thermal and fire resistance, oxidation and corrosion resistance, anti-wear and extreme pressure properties [Walker, T., J. Colloid and Interface Sci., 1973. V. 45, No. 3. P. 372-379]. Fluorinated surfactants are more effective than their hydrocarbon counterparts, they have lower surface tension and critical micelle concentrations, so obtaining such compounds is still an urgent task [Isikawa N. Fluorine compounds. M .: World. 1990, p. 166]. Polyfluorinated alcohols are also valuable intermediates for the production of thermostable lubricants, polymers and oil-repellents [US 3492374, Int. C1. C07f 9/08. Polyfluoropolyoxa-alkyl phospates / R.E. Le Bleu, J.N. Fassnacht. - Publ. 01/27/1970].

This invention relates to the production of 1,3-bis-O- (polyfluoroalkyl) glycerol, which, depending on the length of the fluoroalkyl substituent, can be a promising building block for the production of fluorine-containing surfactants, as well as an intermediate for the production of new surface modifiers and lubricant additives materials.

A known method for producing 1,3-bis-O- (2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl) glycerol ( 4a) [Huang W., Jin C., Derzon DK, Huber TA, Last JA, Provencio PP, et al. J. Colloid and Interface Sci., 2004. V. 272, No. 2, P. 45 7-464], which are synthesized in two stages (Fig. 1).

The first stage is the interaction of epichlorohydrin (2) with polyfluorine-containing alcohol (1a) according to the Williamson type of reaction in a two-phase system using interfacial catalysis at a temperature of 70-75 ° C for 3.5 hours. The separation of the intermediate product of oxirane (3a) is carried out by separation organic layer from water. Then the aqueous layer was extracted with ethyl acetate, the organic fractions were combined, washed with water and dried with magnesium sulfate. Then, ethyl acetate was distilled off, and the intermediate product (3a) was purified by flash chromatography.

In the second stage, the epoxy fragment of fluorinated oxirane (3a) is opened in excess of 1H, 1H-perfluorononol-1 (1a) in the presence of catalytic amounts of potassium methoxide at a temperature of 100 ° C in an inert atmosphere for 18 h. Isolation of the target product (4a) carried out by distillation, followed by purification using flash chromatography. The total number of moles spent on obtaining 1 mole of the final product (4a): polyfluorinated alcohol (1a) - 3 mol, epichlorohydrin (2) - 6 mol, alkali - 6 mol. The main disadvantage of this method is the large number of reagents spent on obtaining the product (3a), with a moderate yield, which according to the results of two stages is 63%. In addition, the reaction is carried out in a complex two-phase system.

Closest to the proposed is a method for producing 1,3-bis-O- (2,2,3,3-tetrafluoropropyl) glycerol (4b), described in [Bazhin D.N., Gorbunova T.I., Zapevalov A. Ya., Kirichenko V.E., Saloutin V.I. Journal of Organic Chemistry. 2007.V. 43. Issue. 5. S. 661-664] - prototype. Obtaining 1,3-bis-O- (2,2,3,3-tetrafluoropropyl) glycerol (4b) is also carried out in two stages (Fig. 1). The first stage is the preparation of 2,2,3,3-tetrafluoropropyloxymethyloxirane (3b) by the interaction of polyfluorinated alcohol (1b) with epichlorohydrin (2) in a two-phase H ₂ O-CH ₂ Cl _{2 system} using interphase catalysis in an alkaline medium. The process temperature is 40 ° C.

The second stage is the opening of the epoxy cycle of 2,2,3,3-tetrafluoropropyloxymethyloxiran (3b) in excess of 1H, 1H, 3H-perfluoropropanol-1 (1b) in an alkaline medium at 40 ° C. The reaction time is 4 hours. The product is isolated by separating the organic layer from the aqueous layer, extracting the aqueous layer of CH ₂ Cl ₂ , combining the organic fractions and drying them with magnesium sulfate. Then the solvent is distilled off, and the target product (4b) is subjected to distillation. The total number of moles spent on obtaining 1 mole of the final product: polyfluorinated alcohol (1b) - 36 mol, epichlorohydrin (2) - 1.6 mol, alkali - 96 mol. The disadvantage of this method is the low yield of the target product, which in the sum of the two stages is 23%. In addition, for the synthesis of the target product (4b), a two-phase system is used.

The task of the invention is to increase the yield of the target product and simplify the process.

The problem is solved in that in the method for producing 1,3-bis-O- (polyfluoroalkyl) glycerol of the general formula:

where at X = H n = 2,4,6; at X = F n = 1-8

the interaction of a fluorinated alcohol of the general formula X (CF ₂ ) _n CH ₂ OH at X = H n = 2,4,6; at X = F n = 1-8 with epichlorohydrin in an alkaline medium during heating, the process is carried out at a molar ratio of fluorinated alcohol: epichlorohydrin: alkali equal to 3: 1: 2 at a temperature of 70-75 ° C, and the target product is isolated by precipitation with mineral acid, separation of the organic layer and distillation in vacuum.

The proposed method for producing 1,3-bis-O- (polyfluoroalkyl) glycerol is characterized by the following advantages:

1) this invention involves a one-step method for producing 1,3-bis-O- (polyfluoroalkyl) glycerol (4) (Fig. 2).

Subject to the ratio of alcohol: epichlorohydrin: alkali equal to 3: 1: 2, the final reaction product is the target alcohol (4a-e). An increase in the proportion of epichlorohydrin (2), as was shown in the above studies, will lead to a different course of the process: oxirane (3) will be necessarily present in the final reaction products (see Scheme 1). The found ratio of reagents is optimal and allows you to synthesize the target products (4) in one stage, in contrast to the prototype;

2) the inventive method for producing compounds (4) does not require the use of a solvent. Excess polyfluorinated alcohol (1) with respect to alkali and epichlorohydrin (2) performs this function;

3) the formation of compounds (4) takes place within 1 h, this time is sufficient for the complete conversion of compound (2);

4) the reaction temperature is 70-75 ° C. This interval is justified by the state of aggregation of the starting reagents (1). For example, compound (1a) is a solid amorphous product that melts at a temperature of 65-67 ° C, so the process temperature cannot be lower than this level for the effective implementation of the reaction in the liquid phase. For the initial reagents, which are liquids at room temperature (1b-e), lowering the reaction temperature is also not desirable, since this leads to an increase in the reaction time and to incomplete conversion of the reagent (2). In this regard, the temperature range of 70-75 ° C is selected experimentally and is optimal for this process;

5) the isolation of 1,3-bis-O- (polyfluoroalkyl) glycerol (4) is carried out by precipitation with an aqueous solution of a mineral acid. After the organic layer is precipitated and separated from the aqueous layer and dried with magnesium sulfate (for products 4b-e), the reaction mass is a mixture of polyfluorinated alcohol (1) and the target product (4), which are separated by vacuum distillation of the oil pump;

6) the claimed changes lead to an increase in the yield of the target product (4) to 69-75%.

The invention is illustrated by the following examples:

Example 1. Obtaining 1,3-bis-O- (2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl) glycerol (4a).

4.50 g (0.01 mol) of 1H, 1H-perfluorononanol-1, 0.28 g (3.00 mmol) of epichlorohydrin, 0.24 g (6.00 mmol) of NaOH are charged into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 75 ° C. Then add an aqueous solution of H ₂ SO ₄ to pH = 7, stirred for 15 minutes, the solid precipitate is filtered off. The solid product is dispersed in a vacuum of an oil pump, separating the excess of 1H, 1H-perfluorononanol-1, a white amorphous solid product is obtained.

Yield 69% (1.98 g), mp. 44-46 ° C, bp 214-216 ° C (12 mmHg) IR spectrum, ν, cm ^-1 : 2934 (CH), 1197, 1143 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 3.71 m (4H, OCH ₂ CH), 4.00 m (5H, CF ₂ C ₂ H, CHOH). NMR spectrum ¹⁹ F (CDCl ₃ , δ, ppm, J / Hz): 35.54 m (2F, η-CF ₂ ), 38.33 m (2F, β-CF ₂ ), 38.93 m (2F, ζ-CF ₂ ), 39.69 m (6F, δ, ε, γ-CF ₂ ), 42.08 m (2F, α-CF ₂ ), 89.4 t (3F, CF ₃ , ³ J _{F, F} = 9.9). Found,%: C 26.15; H 1.21. C ₂₁ H ₁₀ F ₃₄ O ₃ . Calculated,%: C 26.38; H 1.05.

Example 2. Obtaining 1,3-bis-O- (2,2,3,3-tetrafluoropropyl) glycerol (4b).

1.32 g (0.01 mol) of 1H, 1H, 3H-perfluoropropanol-1, 0.28 g (3.00 mmol) of epichlorohydrin, 0.24 g (6.00 mmol) of NaOH are charged into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 70 ° C. Then add an aqueous solution of HCl to pH = 7, mix for 15 min, separate the organic layer, dry it with MgSO ₄ . The excess alcohol is distilled off, the product is distilled in a vacuum of an oil pump, and a colorless oil is obtained.

Yield 74% (0.71 g), bp 164-166 ° C (12 mmHg). IR spectrum, ν, cm ^-1 : 3429 (OH), 2934 (CH), 1093 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 2.44 s (1H, OH), 3.65 m (4H, OCH ₂ CH), 3.90 t (4H, CF ₂ CH ₂ , ² J _{H, F} 12.7), 3.97 m (1H, CHOH), 5.9 t (2H, HCF ₂ , ² J _{H, F} 53.2, ³ J _{H, F} 4.6). NMR spectrum ¹⁹ F (CDCl ₃ , δ, ppm, J / Hz): 22.82 dm (2F, HCF ₂ , ² J _{H, F} 52.0), 37.17 m (2F, CF ₂ CH ₂ ). Found,%: C 33.65; H 3.89. C ₉ H ₁₂ F ₈ O ₃ . Calculated,%: C 33.76, H 3.78.

Example 3. Obtaining 1,3-bis-O- (2,2,3,3,4,4,5,5-octafluoropentyl) glycerol (4B).

2.32 g (0.01 mol) of 1H, 1H, 5H-perfluoropentanol-1, 0.28 g (3.00 mmol) of epichlorohydrin, 0.24 g (6.00 mmol) of NaOH are charged into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 70 ° C. Then add an aqueous solution of H ₂ SO ₄ to pH = 7, mix for 15 min, separate the organic layer, dry it with MgSO ₄ . The excess alcohol is distilled off, the product is distilled in a vacuum of an oil pump, and a colorless oil is obtained.

Yield 72% (1.12 g), bp 175-178 ° C (12 mmHg). IR spectrum, ν, cm ^-1 : 3426 (OH), 2887 (CH), 1163, 1119 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 2.45 s (1H, OH), 3.69 m (4H, OCH ₂ CH), 4.00 m (5H, CF ₂ CH ₂ , CHOH) 6.05 tt (2H, HCF ₂ , ² J _{H, F} 52.0, ³ J _{H, F} 5.4). NMR spectrum ¹⁹ F (CDCl ₃ , δ, ppm, J / Hz): 24.50 dm (2F, HCF ₂ , ² J _{H, F} 52.0), 31.56 m (2F, γ-CF ₂ ), 36.27 m (2F, β-CF ₂ ), 41.91 m (2F, α-CF ₂ ). Found,%: C 30.97; H 2.21. C ₁₃ H ₁₂ F ₁₆ O ₃ . Calculated,%: C 30.02: H 2.33.

Example 4. Obtaining 1,3-bis-O- (2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl) glycerol (4g).

3.32 g (0.01 mol) of 1H, 1H, 7H-perfluoroheptanol-1, 0.28 g (3.00 mmol) of epichlorohydrin, 0.24 g (6.00 mmol) of NaOH are loaded into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 70 ° C. Then add an aqueous solution of H ₂ SO ₄ to pH = 7, mix for 15 min, separate the organic layer, dry it with MgSO ₄ . The excess alcohol is distilled off, the product is distilled in a vacuum of an oil pump, and a colorless oil is obtained.

Yield 68% (1.47 g), mp 203–205 ° C (12 mmHg). IR spectrum, ν, cm ^-1 : 3433 (OH), 2943 (CH), 1196, 1140 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 2.40 s (1H, OH), 3.72 m (4H, OCH ₂ CH), 4.01 m (5H, CF ₂ CH ₂ , CHOH) 6.06 tt (2H, HCF ₂ , ² J _{H, F} 52.0, ³ J _{H, F} 5.1). NMR spectrum ¹⁹ F (CDCl ₃ , δ, ppm, J / Hz): 24.74 dm (2F, HCF ₂ , ² J _{H, F} 52.0), 32.30 m (2F, ε-CF ₂ ), 38.35 m (4F, γ, δ-CF ₂ ), 39.60 m (2F, β-CF ₂ ), 42.14 m (2F, α-CF ₂ ). Found,%: C 28.50; H 1.93. C ₁₇ H ₁₂ F ₃₄ O ₃ . Calculated,%: C 28.35; H 1.68.

Example 5. Obtaining 1,3-bis-O- (2,2,2-trifluoroethyl) glycerol (4e).

10.0 g (0.10 mol) of trifluoroethanol, 2.8 g (0.03 mol) of epichlorohydrin, 2.4 g (0.06 mol) of NaOH are charged into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 70 ° C. Then add an aqueous solution of HCl to pH = 7, mix for 15 min, separate the organic layer, dry it with MgSO ₄ . The excess alcohol is distilled off, the product is distilled, and a colorless oil is obtained.

Yield 75% (5.76 g), bp 198-200 ° C. IR spectrum, ν, cm ^-1 : 3416 (OH), 2940 (CH), 1274, 1134 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 2.41 s (1H, OH), 3.70 m (4H, OCH ₂ CH), 3.89 m (4H, CF ₂ CH ₂ ), 3.99 m (1H, CHOH). ¹⁹ F NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 87.53 t (3F, CF ₃ , ³ J _{H, F} = 8.6). Found,%: C 32.36; H 3.97. C ₇ H ₁₀ F ₆ O ₃ . Calculated,%: C 32.82; H 3.93.

Example 6: preparation of 1,3-bis-O- (2,2,3,3,4,4,5,5,5-nonafluoropentyl) glycerol (4e).

2.50 g (0.01 mol) of 1H, 1H-perfluoropentanol-1, 0.28 g (3.00 mmol) of epichlorohydrin, 0.24 g (6.00 mmol) of NaOH are charged into a round bottom flask with a magnetic stirrer and reflux condenser. The molar ratio of fluorinated alcohol: epichlorohydrin: alkali is 3: 1: 2. With vigorous stirring, the reaction mixture was incubated for 1 h at a temperature of 70 ° C. Then add an aqueous solution of H ₂ SO ₄ to pH = 7, mix for 15 minutes, the organic layer is separated, dried with MgSO ₄ . The excess alcohol is distilled off, the product is distilled in a vacuum of an oil pump, and a colorless oil is obtained.

Yield 72% (1.20 g), bp 162-165 ° C (12 mmHg). IR spectrum, ν, cm ^-1 : 3424 (OH), 2936 (CH), 1222, 1203, 1129 (CO, CF). ¹ H NMR spectrum (CDCl ₃ , δ, ppm, J / Hz): 2.29 s (1H, OH), 3.70 m (4H, OCH ₂ CH), 4.01 m (4H, CF ₂ CH ₂ ). NMR spectrum ¹⁹ F (CDCl ₃ , δ, ppm, J / Hz): 35.42 m (2F, γ-CF ₂ ), 37.44 m (2F, β-CF ₂ ), 41.88 m (2F, α-CF ₂ ), 80.81 tons (3F, ³ J _{F, F} = 9.8, ⁴ J _{F, F} = 2.8 CF ₃ ). Found,%: C 27.91; H 1.89. C ₁₃ H ₁₀ F ₁₈ O ₃ . Calculated,%: C 28.07, H 1.81.

Thus, the proposed method allows you to:

- get the target product in one stage;

- carry out the process without solvent;

- reduce the reaction time to 1 h;

- increase the yield of the target product to 69-75%.

Claims (1)

The method of obtaining 1,3-bis-O- (polyfluoroalkyl) glycerol of the General formula:

where at X = H n = 2,4,6; at X = F n = 1-8
the interaction of a fluorinated alcohol of the general formula X (CF ₂ ) _n CH ₂ OH at X = H n = 2,4,6; at X = F n = 1-8 with epichlorohydrin in an alkaline medium when heated, characterized in that the process is carried out at a molar ratio of fluorinated alcohol: epichlorohydrin: alkali equal to 3: 1: 2, at a temperature of 70-75 ° C, and the allocation the target product is carried out by precipitation with mineral acid, separation of the organic layer and distillation in vacuum.

Images