WO1990008752A1

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Publication number: WO1990008752A1
Application number: PCT/JP1990/000121
Authority: WO
Inventors: Shinsuke Morikawa; Shunichi Samejima; Hidekazu Okamoto; Keiichi Ohnishi; Shin Tatematsu
Original assignee: Asahi Glass Company Ltd.
Priority date: 1989-02-02
Filing date: 1990-02-01
Publication date: 1990-08-09
Also published as: EP0407619A1; CA2026566A1

Abstract

A process for producing a chlorine-containing 2,2-difluoropropane of the formula (2): C3Ha-xClb+xFc, which comprises chlorinating a 2,2-difluoropropane of the formula (1): C3HaClbFc, wherein a, b, c and x are integers satisfying the following conditions: a » 1, b » 0, c » 2, x » 1 and a + b + c = 8.

Description

DESCRIPTION TITLE OF THE INVENTION PROCESS FOR PRODUCING A CHLORINE-CONTAINING 2,2-DIFLUOROPROPANE

TECHNICAL FIELD The present invention relates to a process for producing a chlorine-containing 2,2-difluoropropane.

BACKGROUND TECHNIQUE As a synthetic route for a chlorine-containing 2,2- difluoropropane, a method has been known in which . dichlorofluoromethane or chloromethane is added to an ethylene having a difluoromethylene unit, such as 1,1- dichloro-2,2-difluoroethylene or l-chloro-1,2,2- trifluoroethylene in the presence of aluminum chloride. However, by such a method, not only the desired product, but also a by-product will be formed which has a methylene group other than 2,2-difluoromethylene and which has a boiling point close to that of the desired product. Therefore, in order to obtain a product having a high purity, a multi-stage purification process is required.

DISCLOSURE OF THE INVENTION It is an object of the present invention to overcome such a drawback of the conventional method and to provide a process for efficiently producing a chlorine-containing 2,2-difluoropropane. The present inventors have conducted an extensive research for a process for efficiently producing a chlorine-containing 2,2-difluoropropane and, as a result, have found that a chlorine-containing 2,2-difluoropropane of the following formula (2) can be obtained in good yield by substituting the hydrogen atoms of a 2,2- difluoropropane of the formula (1) by chlorine atoms by chlorination. The present invention is based on this discovery. The present invention provides a process for producing a chlorine-containing 2,2-difluoropropane of the following formula (2), which comprises chlorinating a 2,2-difluoropropane of the following formula (1): C₃H_aCl_bF_c (1) C₃H_a__χCl_b+χF_c (2) wherein a, b, c and x are integers satisfying the following conditions: a ≥ 1, b ≥ 0, c ≥ 2, x ≥ 1 and a + b + c = 8. The chlorine-containing 2,2-difluoropropane of the formula (2) is expected to be useful as a foaming agent, a cooling agent, a propellant or a solvent like conventional chlorofluorocarbons. Particularly, it includes a promising substitute for 1,1,2- trichlorotrifluoroethane as a solvent. BEST MODE OF CARRYING OUT THE INVENTION

Reactions of the following formulas (3) to (6) may be mentioned as specific embodiments for the preparation of a chlorine-containing 2,2-difluoropropane of the formula (2) from a 2,2-difluoropropane of the formula (1).

Cl₂^C3^Hml^C15-π_l^F3^→ 3^Hnl^C15-nl^F3⁽3⁾ 1 ≤ m¹ ≤ 5 0 ≤ n¹ ≤ 4, m¹ > n¹

The 2,2-difluoropropane (C₃H_iniCl₅__mi₃ wherein 1 ≤ πp 2≥ 5) to be used as the starting material includes, for example, 1,2,2-trifluoropropane (R-263c), l-chloro-2,2,3- trifluoropropane (R-253ca), l-chloro-1,2,2- trifluoropropane (R-253cb), l,3-dichloro-l,2,2- trifluoropropane (R-243ca), l,l-dichloro-2,2,3- trifluoropropane (R-243cb), l,l-dichloro-l,2,2- trifluoropropane (R-243cc), l,l,3-trichloro-l,2,2- trifluoropropane (R-233cb), l,l,3,3-tetrachloro-l,2,2- trifluoropropane (R-223ca) and l,l,l,3-tetrachloro-2,2,3- trifluoropropane (R-223cb) .-

The chlorine-containing 2,2-difluoropropane (C₃H_nιCl₅__nιF₃ wherein 0 ≤ n¹ ≤ 4) to be formed by the reaction includes l-chloro-2,2,3-trifluoropropane (R- 253ca), 1-chloro-l,2,2-trifluoropropane (R-253cb), 1,3- dichloro-1,2,2-trifluoropropane (R-243ca), 1,1-dichloro- 2,2,3-trifluoropropane (R-243cb), l,l-dichloro-l,2,2- trifluoropropane (R-243cc), l,l,3-trichloro-2,2,3- trifluoropropane (R-233ca), l,l,3-trichloro-l,2,2- trifluoropropane (R-233cb), l,l,l-trichloro-2,2,3- trifluoropropane (R-233cc), l,l,3,3-tetrachloro-l,2,2- trifluoropropane (R-223ca), l,l,l,3-tetrachloro-2,2,3- trifluoropropane (R-223cb) and 1,1,1,3,3-pentachloro- 2,2,3-trifluoropropane (R-213c) .

Cl,

C3H_rr.2Cl4_-r.2 4 C₃^Hπ₂Cl₄__{n2 4} (4) 1 ≤ m² ≤ 4 0 ≤ n² ≤ 3,² > n²

The 2,2-difluoropropane (C₃H_m2Cl₄__m2F₄ wherein 1 ≤ m²

≤ 4) to be used as the starting material includes

Cl₂ C₃H_rn₃Cl₃__{m3 5} →₃H_n3Cl₃__n3F₅ (5)

1 ≤ m³ ≤ 3 0 ≤ n³ ≤ 2, m³ > n³ The 2,2-difluoropropane (C₃H_m3Cl₃__m3F₅ wherein 1 ≤ m³ ≤. 3 to be used as the starting material includes 1,1,2,2,3-pentafluoropropane (R-245ca), 1,1,1,2,2- pentafluoropropane (R-245cb), 1-chloro-l,2,2,3,3- pentafluoropropane (R-235ca), l-chloro-2,2,3,3,3- pentafluoropropane (R-235cb), 1-chloro-l,1,2,2,3- pentafluoropropane (R-235cc), l,l-dichloro-2,2,3,3,3- pentafluoropropane (R-225ca), l,3-dichloro-l,l,2,2,3- pentafluoropropane (R-225cb) and l,l-dichloro-l,2,2,3,3- pentafluoropropane (R-225cc).

C₃H_m4Cl₂__m4F₆ -→ C₃H_n2Cl₂._n4₅ (6)

1 ≤ m⁴ ≤ 2 0 ≤ n⁴ ≤ 1, m⁴ > n⁴ The 2,2-difluoropropane (C₃H_rπ4Cl₂__ιn4F₆ wherein 1 ≤ m⁴ ≤ 2) to be used as the starting material includes 1,1,2,2,3,3-hexafluoropropane (R-236ca), 1,1,1,2,2,3- hexafluoropropane (R-236cb) , l-chloro-1,2,2,3,3,3- hexafluoropropane (R-226ca) and l-chloro-1,1,2,2,3,3- hexafluoropropane (R-226cb).

The chlorine-containing 2,2-difluoropropane (C₃H_nCl₂__nF₆ wherein 0 ≤ n ≤ 1)^"to be formed by the reaction includes 1-chloro—1,2,2,3,3,3-hexafluoropropane (R-226ca), 1-chloro-l,1,2,2,3,3-hexfluoropropane (R- 226cb), 1,3-dichloro-l,1,2,2,3,3-hexafluoropropane (R- 216ca) and 1,1-dichloro-l,2,2,3,3,3-hexafluoropropane (R- 216cb) . These products can be separated by a usual method such as distillation.

For the reaction, a radical-generating source such as light, heat or a radical initiator, or a combination thereof, may be used. The radical initiator to be used is not particularly limited so long as it is oil-soluble and may be an azo compound or an organic peroxide as shown in the following example. The azo compound may. for example, be α,α'-azobisisobutylonitrile (hereinafter referred to simply as AIBN) or 2,2-azobis-2,4- dimethylvaleronitrile (hereinafter referred to simply as ACVN) . The organic peroxide may, for example, be di-t- butyl peroxide.

The reaction ratio between chlorine and the starting material may be varied in a wide range. In order to control the chlorination selectively at a stage where only single chlorine is introduced, chlorine is used in a low stoichiometrical amount relative to the 2,2- difluoropropane (C₃H_aCl_bF_c). Whereas, to let all the hydrogen atoms of the 2,2-difluoropropane react substantially completely, chlorine is used in an amount larger than stoichiometry relative to total molar amount of the starting material, for example, in an amount of 2 or more molar times.

The reaction temperature may suitably be chosen depending upon the radical-generating source and is usually from -78 to 450°C. In the present invention, when the reaction is conducted in a liquid phase, a solvent may be employed. The solvent to be used is not particularly limited so long as it is capable of dissolving the propane as the starting material and the radical initiator if used, and will hardly be chlorinated itself. For example, a halogenated hydrocarbon such as carbon tetrachloride may suitably be used. There is no specific limitation to the reaction pressure, when the reaction is conducted in a gas phase. The pressure for the reaction is not particularly limited and may range from reduced pressure to above atmospheric. When the reaction is conducted in a liquid phase, the pressure is chosen so that the starting material 2,2- difluoropropane can adequately be present in the liquid phase and may vary depending upon the type of the solvent. In the case of a gas phase reaction, chlorine may be introduced into a reactor together with the starting material as in a flow system, or may be charged initially. In the case-of a liquid phase reaction, it may also be charged initially, but it is preferable to bubble into the liquid phase.

Now, the present invention^"will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted by such specific Examples. EXAMPLE 1-1

A 1,000 cc glass reactor equipped with a condenser of -78°C, was cooled to -20°C, and 300 g of 1,2,2- trifluoropropane was charged. Then, 107 g of chlorine gas was gradually introduced while stirring under irradiation by a high pressure mercury lamp of 500 W.

After the reaction for 6 hours, the product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 1-1. EXAMPLE 1-2

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,2- trifluoropropane and 214 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 1-1. EXAMPLE 1-3 The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,2,2- trifluoropropane and 430 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 1-1. EXAMPLE 1-4

The reaction was conducted^"for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,2,2- trifluoropropane and 214 g of chlorine gas were used, and 200 g of CC1₄ was used as the solvent for the reaction. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 1-1. Table 1-1

EXAMPLE 1-5

Into a 1,000 cc Hastelloy C autoclave, 300 g of

20 1,2,2-trifluorolpropane and 20 g of di-t-butyl peroxide were charged. Then, the temperature was raised to 120°C, and while stirring, 214 g of chlorine gas was supplied at a rate of 50 g/hr over a period of 4 hours. Then, the reaction was continued for further 12 hours. The product

25 after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 1-2. EXAMPLE 1-6

The reaction was conducted in the same manner as in Example 1-5 except that 20 g of AIBN was used as a radical initiator. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 1-2. EXAMPLE 1-7

An Inconel 600 reactor having an inner diameter of

1.27 cm and a length of 20 cm, was maintained at 430°C, and gasified 1,2,2-trifluoropropane and chlorine gas were supplied at a rate of 300 ml/min, respectively. The reaction was conducted continuously for 4 hours. The product after removal of acid components was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown iri Table 1-2.

Table 1-2^"

EXAMPLE 1-8

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g 1-chloro- 2,2,3-trifluoropropane and 160 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and -NMR. The results are shown in Table 1- 3.

Table 1-3

EXAMPLE 1-9 The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1-chloro- 1,2,2-trifluoropropane and 160 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 1- 4. Table 1-4

EXAMPLE 1-10

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,3- dichloro-1,2,2-trifluoropropane and 130 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 1-5.

EXAMPLE 1-11

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1- dichloro-2,2,3-trifluoropropane and 130 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 1-6.

Table 1-6

EXAMPLE 1-12

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1- dichloro-l,2,2-trifluoropropane and 130 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 1-7. Table 1-7

EXAMPLE 1-13

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,3- trichloro-2,2,3-trifluoropropane and 105 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 1-8. -

Table 1-8

EXAMPLE 1-14

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,3- trichloro-1,2,2-trifluoropropane and 53 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^- MR. The results are shown in Table 1-9.

EXAMPLE 1-15

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,1- trichloro-2,2,3-trifluoropropane and 53 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^- M . The results are shown in Table 1-10.-

Table 1-10

EXAMPLE 1-16

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,3,3- tetrachloro-1,2,2-trifluoropropane and 90 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 1-11.

EXAMPLE 1-17

The reaction was conducted for 6 hours in the same manner as in Example 1-1 except that 300 g of 1,1,1,3- tetrachloro-2,2,3-trifluoropropane and 90 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 1-12.

Table 1-12

Conversion for CC1₃CF₂CHC1F (%) 97

Selectivity for CC1₃CF₂CC1₂F (%) 100

EXAMPLE 2-1

A 1,000 cc glass reactor equipped with a condenser of -78°C, was cooled to -20°C, and 300 g of 1,2,2,3- tetrafluoropropane was charged. Then, 95 g of chlorine gas was gradually introduced while stirring under irradiation by a high pressure mercury lamp of 500 w. After the reaction for 6 hours, the product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table^'2-1. EXAMPLE 2-2

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,2,2,3- tetrafluoropropane and 185 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 2-1. EXAMPLE 2-3

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,2,2,3- tetrafluoropropane and 370 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 2-1. EXAMPLE 2-4

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,2,2,3- tetrafluoropropane, 185 g of chlorine gas and 200 g of CC1₄ as a solvent were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-1.

Table 2-1

10

EXAMPLE 2-5

Into a 1,000 cc Hastelloy C autoclave, 300 g of 15 1,2,2,3-tetrafluorolpropane and 20 g of di-t-butyl peroxide were charged. Then, the temperature was raised to 120°C, and while stirring, 185 g of chlorine gas was supplied at a rate of 50 g/hr over a period of 4 hours.

Then, the reaction was continued for further 12 hours. 20 The product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and ^Η-NMR.

The results are shown in Table 2-2.

EXAMPLE 2-6^"

The reaction was conducted in the same manner as in 25 Example 2-5 except that 300 g of 1,2,2,3- tetrafluoropropane and 20 g of AIBN as a radical initiator were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 2-2. EXAMPLE 2-7

An Inconel 600 reactor having an inner diameter of 1.27 cm and a length of 20 cm, was maintained at 430°C, and gasified 1,2,2,3-tetrafluoropropane and chlorine gas> were supplied at a rate of 150 ml/min, respectively. The reaction was conducted continuously for 4 hours. The product after removal of acid components was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-2.

Table 2-2

EXAMPLE 2-8

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,1,2,2- tetrafluoropropane and 185 g of chlorine gas were used and the reaction was carried out at -30°C. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H- NMR. The results are shown in Table 2-3,

Table 2-3

EXAMPLE 2-9

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1-chloro- 2,2,3,3-tetrafluoropropane and 140 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 2- 4.

Table 2-4

- 22 -

EXAMPLE 2-10

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1-chloro- 1,2,2,3-tetrafluoropropane and 140 g of chlorine gas were used. The product was analyzed by gas chromatography and_by 19_F__{NMR an}d^l-H-NMR.^Tne results are shown in Table 2- 5.

Table 2-5

10

15 EXAMPLE 2-11

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1-chloro- 1,1,2,2-tetrafluoropropane and 140 g of chlorine gas were used. The product was analyzed by gas chromatography and

20 by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 2- 6.

Table 2-6

25

EXAMPLE 2-12

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,3- dichloro-1,2,2,3-tetrafluoropropane and 115 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 2-7.

Table 2-7

EXAMPLE 2-13

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except^"that 300 g of 1,1- dichloro-2,2,3,3-tetrafluoropropane and 115 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-8.

Table 2-8

EXAMPLE 2-14

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,3- dichloro-1,1,2,2-tetrafluoropropane and 58 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 2-9.

Table 2-9

EXAMPLE 2-15

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except^"that 300 g of 1,1- dichloro-l,2,2,3-tetrafluoropropane and 58 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 2-10.

Table 2-10

EXAMPLE 2-16

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,1,3- trichloro-2,2,3,3-tetrafluoropropane and 100 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-11.

EXAMPLE 2-17 The reaction was conducted for 6 hours in the same manner as in Example 2-1 except^"that 300 g of 1,1,3- trichloro-1,2,2,3-tetrafluoropropane and 100 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-12.

EXAMPLE 2-18

The reaction was conducted for 6 hours in the same manner as in Example 2-1 except that 300 g of 1,1,1- trichloro-2,2,3,3-tetrafluoropropane and 100 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 2-13.

Table 2-13

Conversion for CC1₃CF₂CHF₂ (%) 91

Selectivity for CC1₃CF₂CC1F₂ (%) 100

EXAMPLE 3-1 A 1,000 cc glass reactor equipped with a condenser of -78°C, was cooled to -20°C, and^"30Q g of 1,1,2,2,3- pentafluoropropane was charged. Then, 80 g of chlorine gas was gradually introduced while stirring under irradiation by a high pressure mercury lamp of 500 W. After the reaction for 6 hours, the product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 3-1. EXAMPLE 3-2 The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1,2,2,3- pentafluoropropane and 160 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 3-1. EXAMPLE 3-3

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1,2,2,3- pentafluoropropane and 320 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 3-1. EXAMPLE 3-4

10 The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1,2,2,3- pentafluoropropane, 160 g.of chlorine gas and 200 g of CC1₄ as a solvent were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The

15 results are shown in Table 3-1.

Table 3-1

EXAMPLE 3-5

Into a 1,000 cc Hastelloy C autoclave, 300 g of

1,1,2,2,3-pentafluorolpropane and 20 g of di-t-butyl peroxide were charged. Then, the temperature was raised to 120°C, and while stirring, 200 g of chlorine gas was supplied at a rate of 50 g/hr over a period of 4 hours.

Then, the reaction was continued for further 12 hours.

The product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 3-2.

EXAMPLE 3-6

The reaction was conducted while 200 g of chlorine gas was supplied at a rate of 50 g/hr for 4 hours in the same manner as in Example 3-5 except that 300 g of 1,1,2,2,3-pentafluoropropane and 20 g of AIBN as a radical initiator were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 3-2.

EXAMPLE 3-7 An Inconel 600 reactor having an inner diameter of

1.27 cm and a length of 20 cm, was maintained at 430°C, and gasified 1,1,2,2,3-pentafluoropropane and chlorine gas were supplied at a rate of 150 ml/min, respectively.

The reaction was conducted continuously for 4 hours. The product after removal of acid components was analyzed by gas chromatography and by¹⁹F-NMR and ^- MR. The results are shown in Table 3-2. - 29 -

Table 3-2

EXAMPLE 3-8

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1,1,2,2- pentafluoropropane and 160 g of chlorine gas were used and the reaction was carried out^" at -30°C. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH- NMR. The results are shown in Table 3-3.

Table 3-3

EXAMPLE 3-9

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of l-chloro- 1,2,2,3,3-pentafluoropropane and 130 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR. The results are shown in Table 3-4.

Table 3-4

EXAMPLE 3-10

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1-chloro- 2,2,3,3,3-pentafluoropropane and 65 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^- MR. The results are shown in Table 3-5.

Table 3-5

Conversion for CF₃CF₂CH₂C1 ( % ) 37

Selectivity for CF₃CF₂CHC1₂ ( % ) 81

Selectivity for CF₃CF₂CC1₃ ( % ) 19 EXAMPLE 3-11

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1-chloro- 1,1,2,2,3-pentafluoropropane and 65 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 3-6.

Table 3-6

EXAMPLE 3-12

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1- dichloro-2,2,3,3,3-pentafluoropropane and 105 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^- R. The results are shown in Table 3-7.

Table 3-7-

Conversion for CF₃CF₂CHC1₂ ( % ) 99

Selectivity for CF₃CF₂CC1₃ ( % ) 100 EXAMPLE 3-13

The reaction was conducted for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,3- dichloro-1,1,2,2,3-pentafluoropropane and 105 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 3-8.

EXAMPLE 3-14

The reaction was conducted^"for 6 hours in the same manner as in Example 3-1 except that 300 g of 1,1- dichloro-l,2,2,3,3-pentafluoropropane and 105 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and^LH-NMR. The results are shown in Table 3-9.

Table 3-9

Conversion for CC1₂FCF₂CHF₂ (%) 91

Selectivity for CC1₂FCF₂CC1F₂ (%) 100 EXAMPLE^* 4-1

A 1,000 cc glass reactor equipped with a condenser of -78°C, was cooled to -20°C, and 300 g of 1,1,2,2,3,3- hexafluoropropane was charged. Then, 70 g of chlorine gas was gradually introduced while stirring under irradiation by a high pressure mercury lamp of 500 W. After the reaction for 6 hours, the product after removal of acid components, was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 4-1. EXAMPLE 4-2

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of 1,1,2,2,3,3-hexafluoropropane and 140 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 4-1. EXAMPLE 4-3

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of

1,1,2,2,3,3-hexafluoropropane and 280 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 4-1. EXAMPLE 4-4

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of 1,1,2,2,3,3-hexafluoropropane, 140 g of chlorine gas and 200 g of CC1₄ as a solvent were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-N R. The results are shown in Table 4-1.

15

EXAMPLE 4-5

Into a 1,000 cc Hastelloy C autoclave, 300 g of 1,1,2,2,3,3-hexafluorolpropane and 20 g of di-t-butyl peroxide were charged. Then, the temperature was raised

20 to 120°C, and while stirring, 160 g of chlorine gas was supplied at a rate of 40 g/hr over a period of 4 hours. Then, the reaction was continued for further 12 hours. The product after removal of-acid components, was analyzed by gas chromatography and by¹⁹F-NMR and ^-H-NMR.

25 The results are shown in Table 4-2. EXAMPLE 4-6

The reaction was conducted in the same manner as in Example 4-5 except that 300 g of 1,1,2,2,3,3- hexafluoropropane and 20 g of AIBN as a radical initiator were used. 160 of chlorine gas was supplied at a rate of 40 g/hr over a period of 4 hours, and then the reaction was continued for further 12 hours. The product was analyzed by gas chromatography and by¹⁹F-NMR and^XH-NMR. The results are shown in Table 4-2. EXAMPLE 4-7

An Inconel 600 reactor having an inner diameter of 1.27 cm and a length of 20 cm, was maintained at 430°C, and gasified 1,1,2,2,3,3-hexafluoropropane and chlorine gas were supplied at a rate of 150 ml/min, respectively. The reaction was conducted continuously for 4 hours. The product after removal of acid components was analyzed by gas chromatography and by¹⁹F-NMR and -"-H-NMR. The results are shown in Table 4-2.

Table 4-2

EXAMPLE 4-8

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of 1,1,1,2,2,3-hexafluoropropane and 70 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 4-3.

Table 4-3

EXAMPLE 4-9

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of 1-chloro- 1,2,2,3,3,3-hexafluoropropane and 120 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and ^-NMR. The results are shown in Table 4-4.

Table 4-4

Conversion for CF₃CF₂CHC1F (%) 97

Selectivity for CF₃CF₂CC1₂F (%) 100 8752

- 37 -

EXAMPLE 4-10

The reaction was conducted for 6 hours in the same manner as in Example 4-1 except that 300 g of 1-chloro- 1,1,2,2,3,3-hexafluoropropane and 120 g of chlorine gas were used. The product was analyzed by gas chromatography and by¹⁹F-NMR and¹H-NMR. The results are shown in Table 4-5.

Table 4-5

Conversion for CC1F₂CF₂CHF₂ (%) 95

Selectivity for CC1F₂CF₂CC1F₂ (%) 100

The present invention is effective for producing a chlorine-containing 2,2-difluoropropane selectively by chlorinating a 2,2-difluoropropane^,

Claims

1. A process for producing a chlorine-containing 2,2- difluoropropane of the following formula (2), which comprises chlorinating a 2,2-difluoropropane of the following formula (1):

^CsW c D

C₃H_a__χCl_b+χF_c (2) wherein a, b, c and x are integers satisfying the following conditions: a ≥ l, b ≥ 0, c .≥ 2, x ≥ l and a + b + c = 8.

2. The process according to Claim 1, wherein the chlorination is conducted- in the presence of a radical- generating source.

3. The process according to Claim 2, wherein the radical-generating source is light, heat or a radical initiator.

4. The process according to Claim 1, wherein the 2,2- difluoropropane of the formula (1) is C₃H_mιCl₅__mιF₃ (1 ≤ m¹ -≥ 5), and the chlorine-containing 2,2-difluoropropane of the formula (2) is C₃H_nιCl₅__n_F₃ (0 ≤ n¹ ≤ 4, m¹ > n¹).

5. The process according to Claim 1, wherein the 2,2- difluoropropane of the formula (1) is C₃H_rn2Cl₄__ιπ2F₄ (1 ≤ m² ≤ 4), and the chlorine-containing 2,2-difluoropropane of the formula (2) is C₃H_n2Cl₄__n2F₄ (0 ≤ n² ≤ 3, m² > n²).

6. The^' process according to Claim 1, wherein the 2,2- difluoropropane of the formula (1) is C₃H_rn3Cl₃__m3F₅ (1 ≤ m³ = 3), and the chlorine-containing 2,2-difluoropropane of the formula (2) is C₃H_n3Cl₃__n3F₅ (0 ≤ n³ ≤ 2, m³ > n³).

7. The process according to Claim 1, wherein the 2,2- difluoropropane of the formula (1) is C₃H_m4Cl₂__m F₆ (1 ≤≥ m⁴ -S- 2), and the chlorine-containing 2,2-difluoropropane of the formula (2) is C₃H_n4Cl₂__ F₆ (0 ≤ n⁴ ≤ 1, m⁴ > n⁴).