RU2199517C2 - 1,1,1,3,3-pentachlorobutane production process - Google Patents

Abstract

FIELD: industrial organic synthesis. SUBSTANCE: 1,1,1,3,3-pentachlorobutane is prepared by reaction of carbon tetrachloride with 2-chloropropene in presence of telomerization catalyst, which consists of at least one cuprous or cupric compound. Reaction is carried out at 40-200 C, preferably in presence of solvent, in particular nitrile, amide, or trialkylposphine oxide. EFFECT: increased yield of 1,1,1,3,3-pentachlorobutane. 10 cl, 5 tbl, 29 ex

Description

 The invention relates to a method for producing 1,1,1,3,3-pentachlorobutane, in particular by telomerization reaction between carbon tetrachloride and 2-chloroprop-1-ene.

 1,1,1,3,3-Pentachlorobutane is of considerable industrial interest because it leads, by fluorination, to the corresponding pentafluorinated derivative (HFC-365 mfc), used in particular as a gas filler or a third-generation solvent that does not cause destructive impact on the ozone layer and not conducive to global warming of the planet due to the greenhouse effect.

 R. Freidlina et al. (Bull. Acad. Sci. USSR, 28, 1766-1769 [1979]) obtained 1,1,1,3,3-pentachlorobutane in negligible yield by reaction between carbon tetrachloride and 2-chloroprop-1-ene in ethanol or isopropanol in the presence of iron pentacarbonyl as a catalyst. An insignificant yield, on the one hand, and high catalyst toxicity, on the other hand, are the reason why this synthesis method is difficult to apply in industry.

 Another way to obtain 1,1,1,3,3-pentachlorobutane, recently described by Kotora and his collaborators (React. Kinet. Catal. Lett., 44 (2), 415-419 [1991]), is to introduce the interaction 1 1,1-trichloroethane with 1,1-dichloroethene in the presence of monovalent copper chloride and amine. The resulting yield is negligible (8%), and this synthesis method, therefore, also turns out to be unsuitable for use in industry.

 Therefore, the invention relates to the development of a method that allows, in one step and when using readily available reagents to obtain 1,1,1,3,3-pentachlorobutane in high yield.

 Thus, the invention relates to a method for producing 1,1,1,3,3-pentachlorobutane by reaction between carbon tetrachloride and 2-chloroprop-1-ene in the presence of a catalyst comprising at least one copper (I) compound or a copper compound - (II). Typically, copper (II) compounds are preferred.

 The copper (I) compound or the copper (II) compound is preferably selected from copper halides, copper carboxylates, mixed copper salts or complexes formed with neutral ligands.

 Of the halides of copper (I) or copper (II), in particular, fluorides, chlorides, bromides or iodides are used. Chlorides and iodides are preferred. Copper (II) chloride is particularly preferred.

 Of the mixed salts of copper (I) or copper (II), in particular, hydroxyhalides are used. Medium (II) hydroxychloride is preferred.

 Of the carboxylates of copper (I) or copper (II), in particular, salts formed with carboxylic acids such as acetic acid, propionic acid, butyric acid, cyclohexanebutyric acid or benzoic acid find use. Preferred are acetates of copper (I) or copper (II), that is, salts formed with acetic acid. Particularly preferred is cyclohexane butyrate copper- (II).

 Of the complexes formed with copper (I) or copper (II) compounds, in particular, complexes obtained with neutral ligands, such as phosphines, for example triphenylphosphine, or with acetylacetone, are used. Medium (II) acetylacetonate is preferred.

 Preferably, the catalyst is selected from copper (I) acetate or copper (II) acetate, copper (II) cyclohexane butyrate, a complex of monovalent copper chloride with triphenylphosphine, copper (II) acetylacetonate, copper (II) hydroxychloride, copper ( I), copper iodide (I) or copper (II) chloride. Of these catalysts, copper (II) chloride, copper (II) acetate, copper (II) hydroxychloride, copper (II) cyclohexan butyrate and copper (II) acetylacetonate are preferred.

 In the case of a periodically carried out method, the molar ratio between the introduced copper compound and 2-chloroprop-1-ene is usually greater than or equal to 0.001, preferably greater than or equal to 0.002. Preferably, it is greater than or equal to 0.005. The molar ratio between the introduced copper compound and 2-chloroprop-1-ene is most often lower than or equal to 5, preferably lower than or equal to 1. Preferably, it is lower than or equal to 0.5. Particularly preferably, this ratio is greater than or equal to 0.01 and lower than or equal to 0.1.

 In the case of a continuous process, the molar ratio between the introduced catalyst and 2-chloroprop-1-ene is approximately in the same range as in the case of a batch process, but, however, it can reach a value of 50.

 It is understood that the amount of catalyst used is expressed in the case of a periodically carried out method in relation to the initial amount of 2-chloroprop-1-ene used and in the case of a continuously carried out method in relation to a constant amount of 2-chloroprop-1-ene in the reactor.

 The molar ratio between carbon tetrachloride and the 2-chloroprop-1-ene used can vary widely. This ratio is usually equal to or higher than 0.1, preferably equal to or higher than 0.5. Preferably, it is greater than or equal to 1. This ratio is usually, however, equal to or lower than 20, preferably equal to or lower than 10. Preferably, this ratio is equal to or lower than 8.

Typically, the reaction is carried out at a temperature above or equal to room temperature. Preferably, the temperature is equal to or higher than 40 ^{° C.} and preferably equal to or higher than 80 ^° C. Typically, the reaction temperature does not exceed 200 ^° C. Advantageously, especially when using copper- (II) hydroxychloride as a catalyst, the reaction temperature is higher than or equal to 90 ^{° C.} preferably it is higher or equal to 100 ^o C. it is usually lower than or equal to 150 ^o C, more precisely it is lower than or equal to 140 ^C. when using hydroxychloride copper- (II) is particularly preferred to carry out the reaction at a temperature close to 130 ^o C.

 The duration of the reaction in the case of a periodically carried out method or the residence time in the case of a continuously carried out method depends on various parameters, such as the reaction temperature, the concentration of reactants and catalyst in the reaction mixture and their molar ratios. Usually, depending on these parameters, the residence time or duration of the reaction can be from 5 seconds to 20 hours.

 The pressure is usually greater than or equal to atmospheric pressure and equal to or lower than 15 bar. Preferably it is lower than or equal to 10 bar. Since the telomerization reaction is usually carried out in the liquid phase, the pressure, depending on the temperature of the reaction medium, is preferably chosen so as to maintain the reaction medium mainly in the form of a condensed phase.

 In a first embodiment of the method according to the invention, the reaction is carried out in the presence of a solvent. Any solvent may be used in which the reagents form the desired product in an acceptable yield. Preferably, the reaction solvent is alcohol, nitrile, amide, lactone, trialkylphosphine oxide, trialkylphosphate, or another polar solvent.

Of the alcohols used as a solvent for the reaction, in particular, methanol, ethanol, isopropanol and tert.-butanol are used. Of the nitriles used as a solvent for the reaction, in particular, aliphatic nitriles, especially acetonitrile, propionitrile or adiponitrile, and aromatic nitriles, especially benzonitrile or toluonitrile, are used. Among the nitriles, propionitrile and adiponitrile are preferred. Of the amides used as a solvent for the reaction, linear amides, such as N, N-dimethylacetamide and N, N-dimethylformamide, and cyclic amides, such as N-methylpyrrolidone, are used. You can also specify hexamethylphosphoramide. Of the lactones used as a solvent for the reaction, in particular, γ-butyrolactone can be mentioned. Among the trialkylphosphine oxides used as a solvent for the reaction, in particular, are compounds of the formula (R1R2R3) PO, in which Rl, R2 and R3 are the same or different, preferably linear, alkyl groups with 3-10 carbon atoms. In particular, tri (n-butyl) phosphine oxide, tri (n-hexyl) phosphine oxide, tri- (n-octyl) phosphine oxide, n-octyl di (n-hexyl) phosphine oxide and n-hexyl di (n-octyl) are used phosphine oxide and mixtures thereof. Of the trialkyl phosphates used as a solvent for the reaction, in particular, there can be mentioned compounds of the formula (RO) ₃ PO, in which R is preferably a linear alkyl group with 3-10 carbon atoms. In particular, tributyl phosphate is used. Other polar solvents may also include 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide and tetrahydrofuran. Preferably, the solvent is an amine or trialkylphosphine oxide. Particularly good results are obtained when using N-methylpyrrolidone, N, N-dimethylacetamide, and also when using a mixture of tri (n-hexyl) phosphine oxide, tri (n-octyl) phosphine oxide, n-octyl di (n-hexyl) phosphine oxide and n-hexyl di (n-octyl) phosphine oxide.

 The amount of solvent introduced in the first embodiment of the method according to the invention is not critical. However, a too dilute solution does not favor a high yield and a high degree of conversion. Preferably, the molar ratio of solvent to 2-chloroprop-1-ene is equal to or higher than 0.05. Preferably, this ratio is equal to or higher than 0.1. The molar ratio of solvent to 2-chloroprop-1-ene is usually equal to or lower than 20, preferably equal to or lower than 15. Preferably, this ratio is equal to or higher than 0.2 and equal to or lower than 10. In the reaction medium, the amount of solvent can vary in molar ratio within from about 5 times to about 500 times the amount of catalyst, preferably about 10 times to about 200 times.

 In a second, preferred embodiment of the method according to the invention, the reaction is carried out in the presence of a cocatalyst. The cocatalyst can be selected, in particular, among amines, amides and trialkylphosphine oxides. As amines used as a cocatalyst, aliphatic amines or aromatic amines can be mentioned. Of the aliphatic amines, primary amines, secondary amines and tertiary amines are used. Alkanolamines, alkylamines, such as ethanolamine, n-butylamine, tert.-butylamine, n-propylamine, isopropylamine, benzylamine, hexamethylenediamine, diethylamine, triethylamine, or aromatic amines, such as pyridine or aniline, are usually used as an amine. Amides used as cocatalyst are N-methylpyrrolidone and N, N-dimethylformamide. As used as a cocatalyst trialkylphosphine oxides can be called compounds that are used as a solvent according to the first variant embodiment of the invention. Preferred cocatalysts are aliphatic alkyl amines such as n-butylamine, tert.-butylamine, n-propylamine and isopropylamine. Particularly preferred are isopropylamine and tert.-butylamine. Other preferred cocatalysts are trialkylphosphine oxides.

 Copper (II) compounds are especially preferred when the reaction is carried out in the presence of a cocatalyst. Very good results are achieved when using copper- (II) acetate and tert.-butylamine as a cocatalyst.

In this second, preferred embodiment of the method according to the invention, the reaction temperature may be equal to or lower than 120 ^° C. In particular, the presence of cocatalyst allows the reaction to be carried out at a temperature equal to or lower than 100 ^{° C.} while maintaining a high degree of conversion and excellent selectivity. A temperature close to 90 ^o C. is especially recommended.

 The molar ratio between the catalyst and the introduced 2-chloroprop-1-ene is usually greater than or equal to 0.001. Preferably, this ratio is equal to or higher than 0.005. Usually this ratio is equal to or lower than 1, preferably equal to or lower than 0.5. Preferably, this ratio is greater than or equal to 0.01 and lower than or equal to 0.25. Particularly preferably, this ratio is greater than or equal to 0.1 and lower than or equal to 0.2. The amount of cocatalyst used can vary in a molar ratio from about 0.1 times to about 25 times the amount of catalyst, preferably from about 0.5 times to about 20 times.

 The presence of cocatalyst in the reaction mixture does not preclude the use of nitrile or another compound as a solvent.

 In this second embodiment of the method according to the invention, carbon tetrachloride can simultaneously serve as a reagent and a solvent. The molar ratio between carbon tetrachloride and 2-chloroprop-1-ene is then greater than or equal to 2, preferably greater than or equal to 4. Preferably, this ratio is greater than or equal to 4.5. However, in order to avoid too much dilution of the reactants, this ratio is usually lower than or equal to 10, and preferably it is lower than or equal to 8. Preferably, this ratio is lower than or equal to 6.

 The method according to the invention, therefore, allows the synthesis of 1,1,1,3,3-pentachlorobutane in one step, based on readily available reagents, usually with a selectivity of more than 90%.

 Obtained according to the method of the invention, 1,1,1,3,3-pentachlorobutane is the precursor of the corresponding pentafluorinated analogue 1,1,1,3,3-pentachlorobutane (HFC-365 mfc), which can be obtained by treatment with hydrogen fluoride in the presence of a catalyst, such as an antimony salt, a titanium salt, a tantalum salt or a tin salt.

The following examples illustrate the invention without limiting its scope of protection. In these examples, reagents, the solvent and the catalyst are introduced into a 300 ml autoclave, whose inner walls are coated with Teflon ^®. Then the apparatus is hermetically sealed, placed in a vertical oven and the temperature is gradually increased and maintained at the desired value for several hours. Stirring is provided by a core of a magnetic stirrer placed inside the autoclave. At the end of the reaction, the autoclave was allowed to cool, a fluid sample was taken with a syringe and analyzed by chromatography to determine the degree of conversion of 2-chloroprop-1-ene and the selectivity of conversion to 1,1,1,3,3-pentachlorobutane.

 In the tables below, the degree of conversion is the ratio, expressed as a percentage, between the amount of 2-chloroprop-1-ene used, reduced by the unreacted amount at the end of the reaction, and the amount used; the selectivity of conversion to 1,1,1,3,3-pentachlorobutane is the ratio, expressed as a percentage, between the amount of 1,1,1,3,3-pentachlorobutane formed and the amount of 1,1,1,3,3-pentachlorobutane, which would form if all 2-chloroprop-1-ene turned into 1,1,1,3,3-pentachlorobutane.

Examples 1-4
In these examples, 1,1,1,3,3-pentachlorobutane was prepared in the presence of various nitriles and in the presence of a mixture containing 20% CuCl and 80% CuClOH (and hereinafter referred to as CuCl-CuClOH) as a copper compound. The molar ratio of 2-chloroprop-1-ene / CCl ₄ / CuCl-CuClON / nitrile is 1/2 / 0.01 / 1. The reaction is carried out at a temperature of 130 ^o C for 13 hours. The results are presented in table I.

Example 5
Example 1 is repeated using a molar ratio of 2-chloroprop-1-ene / nitrile 1 / 0.5. Achieve a conversion rate of 85% and a selectivity of 85%.

Example 6
Example 1 is repeated using a molar ratio of 2-chloroprop-1-ene / nitrile 1/4. Achieve a conversion rate of 90% and a selectivity of 89%.

Example 7
Example 6 is repeated using anhydrous copper (II) chloride as a catalyst. Achieve a conversion rate of 92% and a selectivity of 98%.

Examples 8 and 9
In these examples, Example 6 is repeated using various molar ratios between 2-chloroprop-1-ene and CuCl-CuClOH. The molar ratio of 2-chloroprop-1-ene / CCl ₄ / propionitrile is 1/2/4. The results are presented in table II.

Example 10
In this example, example 6 is repeated at a temperature of 150 ^° C. A degree of conversion of 99% and a selectivity of 91% are achieved.

Examples 11 and 12
In these examples, 1,1,1,3,3-pentachlorobutane is obtained in the presence of various amines and in the presence of CuCl-CuClOH. The molar ratio of 2-chloroprop-1-ene / CCl ₄ / CuCl-CuClOH / amine is 1/5 / 0.05 / 0.1. The reaction is carried out at a temperature of 90 ^o C for two hours. The results obtained are presented in table III.

Example 13
Example 12 is repeated using copper (II) acetate as a catalyst and a reaction time of 1 hour at a temperature of 90 ^° C. The molar ratio of 2-chloroprop-1-en / CCl ₄ / Cu (COOCH ₃ ) ₂ / amine is 1/5 / 0.05 / 0.15. Achieve a conversion rate of 96% and a selectivity of 97%.

Examples 14-20
Example 11 is repeated using various copper compounds. The results are presented in table IV.

Example 21 (not according to the invention)
Example 6 is repeated, but in the absence of a copper compound. Formation of 1,1,1,3,3-pentachlorobutane is not observed.

Examples 22-25
1,1,1,3,3-Pentachlorobutane is prepared in the presence of various solvents and copper- (II) acetylacetonate as a catalyst. The reaction time is 2 hours. The molar ratios of the reagents, the reaction temperature and the results obtained are presented in table V.

Examples 26 and 27
1,1,1,3,3-Pentachlorobutane is obtained from 2-chloroprop-1-ene and carbon tetrachloride in the presence of copper (II) acetylacetonate as a catalyst and a mixture of four trialkylphosphine oxides [tri (n-hexyl) phosphine oxide, three (n -octyl) phosphine oxide, n-octyl-di (n-hexyl) phosphine oxide and n-hexyl-di (n-octyl) phosphine oxide], manufactured by CYTEC under the name CYANEX ^® 923. The reaction time is 2 hours. The molar ratios of the reactants, reaction temperatures and the results obtained are also presented in table V.

Example 28
Example 24 is repeated using copper (II) acetate as a catalyst. A conversion of 55% and a selectivity of conversion to 1,1,1,3,3-pentachlorobutane of 94% are achieved.

Example 29
1,1,1,3,3-Pentachlorobutane is obtained in the presence of CuCl ₂ as a catalyst and when N-methylpyrrolidone is used as a solvent. The molar ratio of 2-chloroprop-1-en / CCl ₄ / CuCl ₂ / N-methylpyrrolidone is 1 / 2.2 / 0.05 / 3.3. After a reaction for 5 hours at a temperature of 115 ^{° C., a} degree of conversion of 100% and a selectivity of conversion to 1,1,1,3,3-pentachlorobutane of 94% are achieved.

Claims (10)

 1. The method of obtaining 1,1,1,3,3-pentachlorobutane by reaction between carbon tetrachloride and 2-chloroprop-1-ene in the presence of a telomerization catalyst, characterized in that the catalyst includes at least one copper compound - (I) or copper compound - (II).  2. The method according to claim 1, characterized in that the copper compound is selected among copper halides, mixed copper salts, copper carboxylates, complexes with phosphine or acetylacetone or mixtures thereof.  3. The method according to claim 2, characterized in that the catalyst is chosen among copper acetate - (II), copper hydroxychloride - (II), copper cyclohexane butyrate - (II), copper acetylacetonate - (II) and copper chloride - (II).  4. The method according to any one of claims 1 to 3, characterized in that the reaction is carried out in the presence of a solvent.  5. The method according to any one of claims 1 to 4, characterized in that the reaction is carried out in the presence of cocatalyst.  6. The method according to claim 5, characterized in that the cocatalyst is an amine.  7. The method according to claim 6, characterized in that the amine is isopropylamine or tert.-butylamine. 8. The method according to any one of claims 1 to 7, characterized in that the reaction is carried out at a temperature above or equal to 40 ^o C and lower or equal to 200 ^o C.  9. The method according to any one of claims 4 to 8, characterized in that the solvent is nitrile, amide or trialkylphosphine oxide.  10. The method according to p. 9, characterized in that the solvent is chosen among N-methylpyrrolidone, N, N-dimethylacetamide, three (n-hexyl) phosphine oxide, three (n-octyl) phosphine oxide, n-octyl di (n-hexyl ) phosphine oxide, n-hexyl di (n-octyl) phosphine oxide and mixtures thereof. Priority on points:
05/05/1997 - according to claims 1-8;
05/05/1997 and 02.24.1998 - according to claim 9;
02.24.1998 - according to claim 10.

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