RU2605604C1 - Method of producing 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry, specifically to a method of producing 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate, which can be used as a solvent for carrying out reactions as a component of chemical compositions, including for formation of electrolytes of chemical current sources, as well as an alkylating agent. In method of producing 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate 2,2,2,3,3,4,4,5,5-octafluoropentanol is first treated with diethylcarbonate in molar ratio 1:(0.5-1.5) in presence of sodium metal, then produced mixture is fractionated at atmospheric pressure. Advantage of method is simplicity and effectiveness of process with fewer steps and higher output in contrast to known methods. Disclosed method enables to obtain 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate in any industrial reactor equipment without additional improvements.

EFFECT: additional advantage of present method is possibility of regeneration of unreacted 2,2,3,3,4,4,5,5-octafluoropentanol and diethylcarbonate which can be reused for synthesis of 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate and thereby considerably increasing output.

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Description

The invention relates to the field of organic chemistry, and in particular to a method for producing 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate, which can be used as a solvent for carrying out reactions as a component of chemical compositions, including for forming electrolytes of chemical current sources, and also as an alkylating reagent.

A known method for producing 2,2,3,3,4,4,5,5-octafluoropentylethylcarbonate by radical decomposition of 2- (2,2,3,3,4,4,5,5-octafluoropentyloxy) -1,3-dioxolane (Journal of General Chemistry (1992), 62 (6), 1253-6.). As the starting compound, a pre-synthesized orthoester is used, which is heated in the presence of tert-butyl peroxide. The conversion and yield of 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate are not indicated. The disadvantages of the method include the need to synthesize the starting compound by reacting chloroform and 2,2,3,3,4,4,5,5-octafluoropentanol-1, the indiscriminate decomposition reaction, which provides a low conversion value, the absence of a method for isolating the product from the reaction and small output.

A known method for producing 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate by radical decomposition of diethyl- (2,2,3,3,4,4,5,5-octafluoropentyloxy) methane (Journal of General Chemistry ( 1990), 60 (11), 2565-8.) - prototype. A pre-synthesized orthoester is used as the starting compound, which is heated in the presence of tert-butyl peroxide. The conversion was 2%. A significant disadvantage of this method is the need to synthesize a commercially unavailable starting compound, which is obtained by the interaction of chloroform and 2,2,3,3,4,4,5,5-octafluoropentanol-1. In addition, the decomposition reaction proceeds with the formation of several by-products, which entails a small conversion and low yield of the target product. There is no method of isolating the product from the reaction mass.

The objective of the invention is the production of 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate in a simple and effective way using minimal amounts of commercially available reagents.

The problem is solved in that in the method for producing 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate 2,2,3,3,4,4,5,5-octafluoropentanol is first treated with diethyl carbonate in a molar ratio of 1 : (0.5-1.5) in the presence of sodium metal, and then the resulting mixture is fractionated at atmospheric pressure. The reaction is carried out in a standard way in a device for distillation with a direct refrigerator at atmospheric pressure. Fractionation of the mixture is carried out using a standard distillation apparatus with a direct refrigerator at atmospheric pressure, equipped with a reflux condenser. Recommended conditions for the production of 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate have been established experimentally, and are also determined by the ideas about the process described below. Commercially available 2,2,3,3,4,4,5,5-octafluoropentanol and diethyl carbonate are used to produce 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate. The use of a molar ratio of 2,2,3,3,4,4,5,5-octafluoropentanol: diethyl carbonate above 1: 1.5 leads to an excessive and inefficient reagent consumption. The use of a molar ratio of 2,2,3,3,4,4,5,5-octafluoropentanol: diethyl carbonate below 0.5: 1 is ineffective due to the low conversion of the reactants. Fractionation of the mixture must be carried out at atmospheric pressure using a reflux condenser, which ensures effective separation of the components.

The analysis of the composition and structure of 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate is carried out using elemental analysis (element analyzer "PE 2400", Perkin Elmer), infrared Fourier spectroscopy (spectrometer "Nicolet 6700", Thermo scientific) and nuclear magnetic resonance spectroscopy (AVANCE 500 spectrometer, Bruker).

The preparation of 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate is illustrated by the following examples:

Example 1

To a mixture of 13.9 ml (0.1 mol) of 2,2,3,3,4,4,5,5-octafluoropentanol and 6.1 ml (0.05 mol) of diethyl carbonate was added 0.1 g of sodium metal. After complete dissolution of the metal, the mixture is heated and fractional distillation is carried out. Collect the fraction boiling at 193-195 ° C. Yield 1.5 g (10%). n = 1.399. Found,%: C 31.34; H 2.83; F 50.09. For the formula C ₈ H ₈ F ₈ O ₃ calculated,%: C 31.34; H 2.83; F 50.09. ¹ H NMR spectrum, DMSOd ₆ , ppm: 1.25 (t, 3H, CH ₃ ), 4.23 (q, 2H, OCH ₂ CH ₃ ), 4.86 (t, 2H, OCH ₂ CF ₂ ), 7.07 (tt, 1H, CF ₂ H). IR spectrum, cm ^-1 : 2991, 1764, 1267, 1127, 1020.

Example 2

To a mixture of 13.9 ml (0.1 mol) of 2,2,3,3,4,4,5,5-octafluoropentanol and 12.2 ml (0.1 mol) of diethyl carbonate was added 0.2 g of sodium metal. After complete dissolution of the metal, the mixture is heated and fractional distillation is carried out. The fraction boiling at 192-193 ° C is collected. Yield 1.8 g (12%).

Example 3

To a mixture of 13.9 ml (0.1 mol) of 2,2,3,3,4,4,5,5-octafluoropentanol and 18.3 ml (0.15 mol) of diethyl carbonate was added 0.3 g of sodium metal. After complete dissolution of the metal, the mixture is heated and fractional distillation is carried out. The fraction boiling at 192-193 ° C is collected. Yield 3.4 g (22%).

The production method is simple to perform. It uses commercially available compounds, the method eliminates the preliminary synthesis of the starting materials, does not require complex equipment and additional auxiliary devices. A significant advantage of the proposed method for producing 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate is the simplicity and manufacturability of the production process with fewer steps and a large yield, in contrast to the known methods. The inventive method allows to obtain 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate on any industrial reactor equipment without additional improvements. An additional advantage of the proposed method is the possibility of regeneration of unreacted 2,2,3,3,4,4,5,5-octafluoropentanol and diethyl carbonate, which again can be used for the synthesis of 2,2,3,3,4,4,5,5- octafluoropentylethyl carbonate and thereby significantly increase the yield. Octafluoropentylethyl carbonate can be used in its intended form as a solvent for carrying out reactions as a component of chemical compositions, including for the formation of electrolytes of chemical current sources, as well as as an alkylating reagent.

Claims (1)

A method of producing 2,2,3,3,4,4,5,5-octafluoropentylethyl carbonate, characterized in that 2,2,3,3,4,4,5,5-octafluoropentanol is first treated with diethyl carbonate in a molar ratio of 1 :( 0.5-1.5) in the presence of sodium metal, and then the resulting mixture is fractionated at atmospheric pressure.