JPH0977698A - Production of 3-trifluoromethyl-1,1,1,2,2-pentafluoro-butane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain 3-trifluoromethyl-1,1,1,2,2-pentafluorobutane which is useful as a detergent which can take a place of specific flons by allowing trifluoromethyl-pentafluorobutene to react with hydrogen in the presence of a hydrogenation catalyst. SOLUTION: In the presence of a hydrogenation catalyst (preferably platinum or palladium, preferably carried by a catalyst carrier such as a metal oxide, for example, silica, alumina or activated carbon, (B) hydrogen is allowed to react with (C) 3-trifluoro-methyl-1,1,1,2,2-pentafluoro-4-butene to give (D) 3- trifluoro-methyl-1,1,1,2,2-pentafluorobutane. In a preferred embodiment, the reaction is carried out in a vapor phase, the amount of component B is 1-20 moles, preferably 2-5 moles per mole of the component C, the reaction temperature is 0 deg.C-30 deg.C, preferably 50 deg.C-200 deg.C and the reaction pressure is the normal pressure to 1MPa, preferably the normal pressure to 0.2MPa.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing 3-trifluoromethyl-1,1,1,2,2-pentafluorobutane. 3-Trifluoromethyl-1,1,1,2,2-pentafluorobutane is useful in various industrial fields and can be used as a cleaning agent for degreasing cleaning, flux cleaning, draining agent, dry cleaning and the like.

[0002]

2. Description of the Related Art 3-Trifluoromethyl-1,1,1,
2,2-Pentafluorobutane is a US
Although included in the general formula of the compound described in P5275569, its specific production method and use example are not known so far. Conventionally, 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafter abbreviated as R-113) and 1,1,1-trichloroethane (hereinafter abbreviated as ethane) that have been used as detergents Since is a depleting substance in the stratospheric ozone layer, it is currently regulated as a specified CFC, etc., and will be completely abolished in 1996. Therefore, as a substitute for R-113 and ethane for cleaning purposes, hydrochlorofluorocarbon (HCFC), hydrocarbon solvent,
Chlorine-based solvents and water-based cleaning agents have been proposed and put on the market.
However, ozone depletion, flammability / dryness, toxicity /
There are problems with emission regulations, wastewater treatment, etc., and it is difficult to replace R-113 and ethane used up to now as they are, and they cannot be said to be appropriate as substitutes.

In some cases, perfluorocarbon (hereinafter abbreviated as PFC) is used for drying the draining agent and the high boiling solvent. PFC is not currently subject to regulation,
Due to its long atmospheric life, it has a great impact on global warming.

[0004]

DISCLOSURE OF THE INVENTION The present invention does not destroy the ozone layer, has a small effect on global warming, has the performance of conventional R-113 and ethane as a cleaning agent, and is a substitute for PFC. Fluorinated hydrocarbons that can also be used as
The present invention provides a method for producing trifluoromethyl-1,1,1,2,2-pentafluorobutane.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies as to a method for producing 3-trifluoromethyl-1,1,1,2,2-pentafluorobutane, and as a result, have completed the present invention. I arrived. That is, in the present invention, in the presence of a hydrogenation catalyst, hydrogen and 3-trifluoromethyl-1,1,1,2,
3-Trifluoromethyl-1,1,1,2,2 characterized by reacting 2-pentafluoro-4-butene
-A method for producing pentafluorobutane.

The hydrogenation catalyst in the present invention may be any one widely known as a hydrogenation catalyst for olefins, for example, a noble metal catalyst such as platinum, palladium, ruthenium or nickel, preferably platinum or palladium. is there. The form of the catalyst may be a simple metal or may be supported on a suitable carrier, but a supported catalyst having a metal oxide such as silica or alumina or activated carbon as a carrier is preferable.

The reaction can be carried out in a gas phase or a liquid phase, but the gas phase is preferred in view of ease of continuous reaction and the like.
When the reaction is carried out in the gas phase, the amount of hydrogen with respect to the raw material can be largely changed, but it is usually stoichiometric or higher in order to increase the conversion rate of the raw material. That is, the amount of hydrogen with respect to the raw material is 1 to 20, preferably 2 to 5, in molar ratio.
If the reaction temperature is too low, the production rate will be slow and the raw materials or products may condense, and if it is too high, the production of by-products and the deterioration of the catalyst may be accelerated.
It may be in the range of 0 ° C, preferably 50 to 200 ° C.
° C. The reaction pressure may be in a range such that the raw materials or products are not liquefied at the reaction temperature to be carried out, but the apparatus becomes complicated under reduced pressure, and therefore it is from normal pressure to 1 MPa, preferably from normal pressure to 0.2 MPa.

3-trifluoromethyl-1, which is a raw material,
1,1,2,2-Pentafluoro-4-butene is, for example, 2,3-dichloro-hexafluoro-2-butene used as a raw material for radical addition of methanol, dehydrochlorination, tosylation of a hydroxyl group, and potassium fluoride. Can be manufactured in the fluorination step of.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following examples.

[0010]

Example 1 2.5 g of a catalyst in which 5% by weight of palladium was supported on activated carbon was put in a glass tube having an inner diameter of 32 mm. The reactor was kept at 100 ° C. and 3-trifluoromethyl-
1,1,1,2,2-Pentafluoro-4-butene was supplied at a rate of 0.51 g / min and hydrogen was supplied at a rate of 157 ml / min, and the reaction was carried out under normal pressure. The product was collected in a cold trap cooled with dry ice-ethanol and analyzed by gas chromatography. As a result, 3-trifluoromethyl-1,1,1,2,2-pentafluorobutane was obtained with a yield of 95%. Was given. 3-trifluoromethyl-1,1,
The structure of 1,2,2-pentafluorobutane is ¹ H-NM
It was confirmed by R and ¹⁹ F-NMR.

The spectrum data of ¹ H-NMR and ¹⁹ F-NMR are shown below. Chemical shifts were based on tetramethylsilane and trichlorofluoromethane, respectively. ¹ H-NMR (CDCl ₃ ) δ1.4 ppm
(3H, double line), 3.0ppm (1H, multiple line), J
_HH ; 6.8 Hz, ¹⁹ F-NMR (neat) δ-7
0.0ppm (3F, multiple lines), -85.2ppm (3
F, multiple line), -120.0 ppm (1F), -12
0.8 ppm (1F), J _FF ; 9.4, 12.2, 1
4.1 Hz

[0012]

INDUSTRIAL APPLICABILITY According to the present invention, 3-trifluoromethyl-1,1, which is useful as a cleaning agent replacing specific CFCs, etc.
1,2,2-Pentafluorobutane can be easily produced.

Claims (1)

[Claims] 1. Hydrogen and 3-trifluoromethyl-1,1,1,2,2-pentafluoro-4- in the presence of a hydrogenation catalyst.
A method for producing 3-trifluoromethyl-1,1,1,2,2-pentafluorobutane, which comprises reacting with butene.