JPH0417171B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing 2-fluoropropanal represented by the formula _H3C -CHF-CHO...(). More specifically, the present invention provides that in the presence of a group metal catalyst of the periodic table, The present invention relates to a method for producing 2-fluoropropanal by hydroformylating monofluoroethylene represented by: 2-Fluoropropanal obtained by the present invention can be used as a raw material for the synthesis of various compounds. For example, 2 obtained by oxidizing
- Fluoropropionic acid is known to be useful as a herbicide (see JP-A-55-40609). Conventionally, the method for producing 2-fluoropropanal is to use ethyl 2-bromopropionate.
A known method is to exchange nalogen with KF, react with ethyl formate in the presence of a base, and further heat in concentrated sulfuric acid [E. Elkik. Bull.
Soc. Chim. Fr., 2254 (1944)], the number of steps is large, and the overall yield is extremely low at 4%, making it difficult to adopt industrially. The present inventors conducted intensive studies to find an industrial method for producing 2-fluoropropanal, and as a result, discovered that 2-fluoropropanal can be produced in high yield using an easily available catalyst, and completed the present invention. . Monofluoroethylene, which is the raw material of the present invention, is
It is an easily available compound that can be produced by many methods including the reaction of acetylene and HF. The present invention requires that it be carried out in the presence of a Group metal catalyst. Examples of these catalysts include cobalt-based catalysts such as cobalt chloride, cobalt acetate, dicobalt octacarbonyl, and hydridotetracarbonyl cobalt, rhodium chloride, rhodium acetate,
Tetrarhodium dodecacarbonyl, hexalodium hexadecacarbonyl, hydridotetracarbonyl rhodium, hydridocarbonyltris(triphenylphosphine)rhodium, chlorocarbonylbis(triphenylphosphine)rhodium, chlorodicarbonylrhodium dimer, chlorotris(triphenyl) rhodium (phosphine) rhodium, dichlorobis(triphenylphosphine) platinum, platinum catalysts such as platinum potassium chloride, catalysts prepared by adding stannous chloride to these platinum catalysts, ruthenium chloride, ruthenium dodeca Examples include ruthenium-based catalysts such as carbonyl. Furthermore, there is no problem in adding nitrile, amine, phosphine, arsine, etc. to these catalysts. Furthermore, these catalysts are activated carbon,
It can also be used supported on silica, alumina, organic polymers, etc. Among these catalysts, cobalt and rhodium catalysts are preferably used because of their high activity. The amount of catalyst to be used can be generally in the range of 10 ^-1 to 10 ^-6 mol based on monofluoroethylene. Carbon monoxide and hydrogen in the hydroformylation of the present invention can be generally introduced into the system at a pressure of normal pressure to 300 atmospheres to carry out the reaction. The present invention is preferably carried out in a solvent, such as aromatic solvents such as benzene, toluene and xylene, ether solvents such as tetrahydrofuran and dioxane, alcohol solvents such as methanol and ethanol, triethylamine, etc. Amine solvents such as pyridine, carboxylic acids such as acetic acid and ethyl acetate, and esters thereof can be used. Although the reaction varies depending on the catalyst used, it proceeds smoothly at a temperature ranging from room temperature to 300°C. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 _CH2 =CHF+CO+ _H2 → _CH3CHFCHO Hexalodium hexadecacarbonyl (3.6 mg, 3.3×10 ^-3 mmol) and toluene (5 ml) were placed in a 50 ml autoclave and degassed. After introducing fluoroethylene (460 mg, 10 mmol), the mixture was heated and stirred at 80° C. for 7 hours under a carbon monoxide partial pressure of 35 atm and a hydrogen partial pressure of 35 atm. After cooling, the pressure was returned to normal and the contents were analyzed by gas chromatography, and it was found that 2-fluoropropanal had been produced in a yield of 95%. Boiling point: 56-57℃/760mmHg ¹ H NMR (CDCl ₃ :TMS): δ1.46 (d, d, J=
24.0, 7.2Hz, 3H), 4.9 (d, q, J = 49.5, 7.2
Hz, 1H), 9.80 (d, J = 6.9Hz, 1H). ^19F NMR ( _CDCl3 = _CFCl3 ): δ-190.8(m,
1F). Examples 2 to 7 CH ₂ =CHF+CO+H ₂ →CH ₂ CHFCHO Table 1 shows the results of a reaction conducted in the same manner as in Example 1.

[Table] Reference example CH ₃ CHFCHO → CH ₃ CHFCOOH 2-Fluoropropanal (852 mg,
Potassium permanganate (1.27 g, 8.1 mmol) was added little by little to a 2N aqueous sulfuric acid solution (11.2 ml) of 11.2 mmol). After stirring for 1 hour and 40 minutes, 3.8 N sulfuric acid (6.9 ml) was added, and then sodium bisulfite was added. The solution was added until it became colorless. The reaction solution was extracted with ether, dried over sodium sulfate, and the solvent was distilled off under reduced pressure.
Analysis of the residue by gas chromatography revealed that 2-fluoropropionic acid was produced in a yield of 59%.

Claims (1)

[Claims] 1. In the presence of a group metal catalyst of the periodic table, the formula A method for producing 2-fluoropropanal represented by the formula H ₃ C-CHF-CHO, which comprises hydroformylating monofluoroethylene represented by the formula H 3 C-CHF-CHO. 2 Group metal is cobalt or rhodium;
A method according to claim 1.