Patent Description:
Propionic acid derivatives, such as <NUM>,<NUM>-difluoropropionic acid esters, are useful compounds as raw materials of e.g. pharmaceuticals and agricultural chemicals. As a method for producing <NUM>,<NUM>-difluoropropionic acid esters, a method for reacting <NUM>,<NUM>,<NUM>,<NUM>-tetrafluorooxetane with alcohols or phenols in the presence of an alkali metal halide is known from <CIT>.

<NPL>) discloses the synthesis of ethyl-<NUM>-bromo-<NUM>,<NUM>-difluoropropanoate by reacting tetrafluorooxetane with MgBr2 in diethylether.

In the method of <CIT>, after the reaction, (a) a solvent was distilled off, (b) water was added, and (c) an organic solvent was added to perform liquid separation. However, since the reaction liquid contains a large amount of alkali metal fluorides, liquid separation is difficult, which results in poor productivity.

An object of the present disclosure is to solve the above problems and to provide a method for producing a propionic acid derivative having excellent productivity.

The present invention provides a method for producing a compound of formula (<NUM>):
<CHM>
wherein.

The present invention also provides a composition comprising a compound of formula (<NUM>) as defined above and a compound of the formula MFn (<NUM>), wherein M is a cation, and n is an integer corresponding to the valence of M; which composition has a fluorine ion content concentration of > <NUM> to <NUM>/L.

According to the present disclosure, a method for producing a propionic acid derivative having high productivity is provided.

The symbols and abbreviations in the present specification can be understood in the sense commonly used in the technical field to which the present disclosure pertains in the context of the present specification, unless otherwise specified, and specifically, , unless otherwise specified, the following applies herein.

The terms "comprise" and "contain" are used with the intention of including the phrases consisting essentially of and consisting of.

The steps, treatments, and operations described herein can be performed at room temperature. "Room temperature" means a temperature of <NUM>-<NUM>.

The phrase "Cn-m" (n and m each represent a number) indicates that the number of carbon atoms is ≥ n and ≤ m, as can typically be understood by a person skilled in the art.

Examples of the "halogen atom" referred to herein include fluorine, chlorine, bromine, and iodine.

Examples of the "substituents" include halogen, cyano, amino, alkoxy and alkylthio. Two or more substituents may be identical to or different from each other. The number of substituents can be <NUM> to the maximum substitutable number, and it may be <NUM>, <NUM>, <NUM>, or <NUM>.

Examples of "hydrocarbon groups" referred to herein include alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkadienyl, aryl, and aralkyl.

Examples of the "alkyl" referred to herein include linear or branched C<NUM>-<NUM>-alkyl, such as methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl, and hexyl.

The "haloalkyl" referred to herein is alkyl substituted with one or more halogen atoms. Examples include fluoromethyl, difluoromethyl, trifluoromethyl (perfluoromethyl), <NUM>-fluoroethyl, <NUM>,<NUM>-difluoroethyl, <NUM>,<NUM>,<NUM>-trifluoroethyl, <NUM>,<NUM>,<NUM>,<NUM>-tetrafluoroethyl, pentafluoroethyl (perfluoroethyl), and linear or branched-chain C<NUM>-<NUM>-haloalkyl, such as groups in which some or all of the fluorine atoms are replaced by other halogen atoms.

Examples of the "alkoxy" referred to herein include linear or branched C<NUM>-<NUM> alkoxy groups, such as methoxy, ethoxy, propoxy (n-propoxy and isopropoxy), butoxy (n-butoxy, isobutoxy, sec-butoxy, and tert-butoxy), pentyloxy, and hexyloxy.

Examples of the "alkylthio" referred to herein include linear or branched C<NUM>-<NUM>-alkylthio, such as methylthio, ethylthio, propylthio (n-propylthio and isopropylthio), butylthio (n-butylthio, isobutylthio, sec-butylthio, and tert-butylthio), pentylthio, and hexylthio.

Examples of the "alkenyl" referred to herein include linear or branched C<NUM>-<NUM> alkenyl groups, such as vinyl, <NUM>-propen-<NUM>-yl, <NUM>-propen-<NUM>-yl, isopropenyl, <NUM>-buten-<NUM>-yl, <NUM>-penten-<NUM>-yl, and <NUM>-hexen-<NUM>-yl.

Examples of the "alkynyl" referred to herein include linear or branched C<NUM>-<NUM> alkynyl groups, such as ethynyl, <NUM>-propyn-<NUM>-yl, <NUM>-propin-<NUM>-yl, <NUM>-pentyn-<NUM>-yl, and <NUM>-hexyn-<NUM>-yl.

Examples of the "cycloalkyl" referred to herein include C<NUM>-<NUM>-cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

Examples of the "cycloalkenyl" referred to herein include C<NUM>-<NUM>-cycloalkenyl, such as cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and cycloheptenyl.

Examples of the "cycloalkadienyl" referred to herein include C<NUM>-<NUM>-cycloalkadienyl, such as cyclobutadienyl, cyclopentadienyl, cyclohexadienyl, cycloheptadienyl, cyclooctadienyl, cyclononadienyl, and cyclodecadienyl.

The "aryl" referred to herein the present specification can be monocyclic, bicyclic, tricyclic, or tetracyclic.

The "aryl" referred to herein can be C<NUM>-<NUM>-aryl.

Examples of the "aryl" referred to herein include phenyl, <NUM>-naphthyl, <NUM>-naphthyl, <NUM>-biphenyl, <NUM>-biphenyl, <NUM>-biphenyl, and <NUM>-anthryl.

Examples of the "aralkyl" referred to herein include benzyl, phenethyl, diphenylmethyl, <NUM>-naphthylmethyl, <NUM>-naphthylmethyl, <NUM>,<NUM>-diphenylethyl, <NUM>-phenylpropyl, <NUM>-phenylbutyl, <NUM>-phenylpentyl, <NUM>-biphenylmethyl, <NUM>-biphenylmethyl, and <NUM>-biphenylmethyl.

In one embodiment, the invention relates to a method for producing a compound of formula (<NUM>):
<CHM>
wherein.

R<NUM> is preferably Cl, Br, I, mercapto or alkylthio; more preferably Cl, Br or I; still more preferably Br or I; and particularly preferably I.

R<NUM> is preferably alkyl or haloalkyl; and particularly preferably C<NUM>-<NUM>-alkyl or C<NUM>-<NUM> -haloalkyl.

R<NUM> in formula (<NUM>) can be a group corresponding to R<NUM> in formula (<NUM>). The cation M in formula (<NUM>) is not particularly limited as long as it is a counter ion of R<NUM>, and examples include hydrogen, metal and ammonium. Examples of the metal include alkali metals and alkaline earth metals. Examples of the alkali metals include lithium, sodium, potassium, and cesium. Examples of the alkaline earth metals include magnesium and calcium. Specific examples of the ammonium include primary to quaternary ammonium. Examples of the primary ammonium include C<NUM>-<NUM> alkylamines such as methylamine, ethylamine, propylamine (n-propylamine, isopropylamine), and butylamine, and aniline.

Examples of the secondary ammonium include di-(C<NUM>-<NUM>-alkyl)amines such as dimethylamine, diethylamine, ethylmethylamine, and dipropylamine, pyrrolidine, imidazole, piperidine, and morpholine.

Examples of the tertiary ammonium include tri-(C<NUM>-<NUM>-alkyl)amines such as trimethylamine and triethylamine, pyridine, and quinoline.

Examples of the quaternary ammonium include tetra-(C<NUM>-<NUM>-alkyl)ammonium such as tetramethylammonium and tetraethylammonium. M is preferably a metal, more preferably an alkali metal or an alkaline earth metal, and even more preferably an alkali metal.

n can be suitably selected according to the valence of M, and is, for example, <NUM> or <NUM>.

Examples of the compound of formula (<NUM>) include NaI, KI, CsI, MgI<NUM>, CaI<NUM>, NaBr, KBr, CsBr, MgBr<NUM>, CaBr<NUM>, NaCl, KCl, CsCl, MgCl<NUM>, and CaCl<NUM>.

The compounds of formula (<NUM>) can be used alone or in a combination of two or more.

The lower limit of the amount of the compound of formula (<NUM>) can be, for example, <NUM> mol, preferably <NUM> mol, and even more preferably <NUM> mol, relative to <NUM> mol of the compound of formula (<NUM>).

The upper limit of the amount of the compound of formula (<NUM>) can be, for example, <NUM> mole, preferably <NUM> mole, and even more preferably <NUM> mole, relative to <NUM> mol of the compound represented by formula (<NUM>).

The amount of the compound of formula (<NUM>) can be, for example, <NUM>-<NUM> mol, preferably <NUM>-<NUM> mol, and even more preferably <NUM>-<NUM> mol, relative to <NUM> mol of the compound of formula (<NUM>).

R<NUM> in formula (<NUM>) can be a group corresponding to R<NUM> in formula (<NUM>).

Specific examples of the compound of formula (<NUM>) include alcohols and phenols. Examples of the alcohols include C<NUM>-<NUM>-alkanols such as methanol, ethanol, propanol (n-propanol and isopropanol), and butanol. Examples of the phenols include phenol, cresol, and naphthol.

The compound of formula (<NUM>) may be used alone or in a combination of two or more.

The upper limit of the amount of the compound of formula (<NUM>) can be, for example, <NUM> mol, preferably <NUM> mol, and even more preferably <NUM> mol, relative to <NUM> mol of the compound of formula (<NUM>).

In the reaction of step A, the compound of formula (<NUM>) may be used as a solvent, or a component other than the compound of formula (<NUM>) may be used as a solvent. When the compound of formula (<NUM>) is used as a solvent, it can be preferably ≥ <NUM> mol relative to <NUM> mol of the compound of formula (<NUM>).

Examples of the component other than the compound of formula (<NUM>) include aliphatic hydrocarbons (e.g., hexane), aromatic hydrocarbons (e.g., toluene, xylene), halogenated hydrocarbons (e.g., dichloromethane, dichloroethane, and chloroform), ethers (e.g., diethyl ether and tetrahydrofuran), ketones (e.g., acetone, methyl ethyl ketone), nitriles (e.g., acetonitrile), esters (e.g., ethyl acetate), amides (e.g., dimethylformamide (DMF) and dimethylacetamide (DMAc)).

The components other than the compound of formula (<NUM>) may be used alone or in a combination of two or more.

In the reaction of step A, the reaction temperature and the reaction time are not particularly limited as long as the reaction proceeds.

The lower limit of the reaction temperature can be, for example, -<NUM>, preferably -<NUM>, and even more preferably <NUM>.

The upper limit of the reaction temperature can be, for example, <NUM>, preferably <NUM>, and even more preferably <NUM>.

The reaction temperature can be, for example, in the range of -<NUM> to <NUM>, preferably -<NUM> to <NUM>, even more preferably <NUM>-<NUM>.

The lower limit of the reaction time can be, for example, <NUM> hours, preferably <NUM> hour, and even more preferably <NUM> hours.

The upper limit of the reaction time can be, for example, <NUM> hours, preferably <NUM> hours, and even more preferably <NUM> hours.

The reaction time is in the range of, for example, <NUM>-<NUM> hours, preferably <NUM>-<NUM> hours, and even more preferably <NUM>-<NUM> hours.

Step B is capable of highly removing the compound of formula (<NUM>) from the reaction mixture obtained in step A.

M and n in formula (<NUM>) can respectively correspond to M and n in formula (<NUM>). Examples of the compound of formula (<NUM>) include NaF, KF, CsF, and CaF<NUM>.

The compound of formula (<NUM>) can be a compound with low solubility in water and/or an organic solvent. The solubility at <NUM> can be, for example, ≤ <NUM>/L, preferably ≤ <NUM>/L, and even more preferably ≤ <NUM>/L.

The method of filtration is not limited. The filtration can usually be performed using a filter material, and preferably using a filter material and a filter aid. The method using a filter material and a filter aid may be pre-coating (a method of filtration using a product in which a filter aid layer is formed on a filter material), or body feeding (a method of filtration by adding a filter aid to the reaction mixture in step A).

Examples of the filter material include paper, metal (e.g., stainless steel), polymer (e.g., cellulose, polypropylene, polyester, and polyamide), glass, ceramics, and cloth.

The filter material is preferably porous, for example, a porous membrane or a porous filter.

The average pore diameter of the filter material is not limited, and is, for example, <NUM>-<NUM> pm, preferably <NUM>-<NUM>, and even more preferably <NUM>-<NUM>.

Examples of the filter aid include diatomite (e.g., Celite (trademark)), filter sand (e.g., manganese sand, manganese zeolite, activated carbon, anthracite, ceramic sand), perlite, and cellulose. The filter aids can be used alone or in a combination of two or more. The filter aid is preferably diatomite.

The filter aid, for example, has an average particle size of <NUM>-<NUM> pm, preferably <NUM>-<NUM> pm, and even more preferably <NUM>-<NUM>.

The filtration temperature (internal temperature of the reaction mixture subjected to filtration) is not particularly limited. In terms of filtration efficiency, filtration is preferably performed at room temperature or more.

The lower limit of the filtration temperature is preferably <NUM>, more preferably <NUM>, <NUM>, <NUM>, or <NUM>.

The upper limit of the filtration temperature is preferably <NUM>, more preferably <NUM>, and even more preferably <NUM>.

The filtration temperature is preferably ≥ <NUM>, and more preferably <NUM>-<NUM>.

The filtration can be performed under atmospheric pressure, under pressure, or under reduced pressure, for example, at ≤ <NUM> MPa, and preferably at ≤ <NUM> MPa.

The present method further includes step (C) of performing a liquid separation treatment on the filtrate obtained by the filtration. By combining the steps B and C, the compound of formula (<NUM>) can be further removed.

The liquid separation treatment usually includes the step of adding water and an organic solvent to the filtrate, the step of separating the mixture into the aqueous phase and the organic phase, and collecting the organic phase.

Examples of the organic solvent used in the liquid separation treatment include aliphatic hydrocarbons (e.g., hexane), aromatic hydrocarbons (e.g., toluene and xylene), halogenated hydrocarbons (e.g., dichloromethane, and dichloroethane), ethers (e.g., diethyl ether and tetrahydrofuran), ketones (e.g., methyl ethyl ketone), and esters (e.g., ethyl acetate).

The organic solvents may be used alone or in a combination of two or more. The organic solvent is preferably an ether.

The present method may further include another optional step. Examples of such a step include distillation, concentration, washing, or a combination of two or more steps.

The present composition is a composition comprising a compound of formula (<NUM>) and a compound of formula (<NUM>), wherein the fluorine ion content concentration is > <NUM> to <NUM>/L.

The lower limit of the fluorine ion content concentration can be usually the detection limit or <NUM>/L.

The fluorine ion content concentration thus can be, for example, <NUM> to <NUM>/L.

The composition further contains the compound of formula (<NUM>).

The lower limit of the content of the compound of formula (<NUM>) in the composition can be, for example, the detection limit or <NUM> mass%.

The upper limit of the content of the compound of formula (<NUM>) in the composition may be, for example, <NUM> mass%, and preferably <NUM> mass%.

The content of the compound of formula (<NUM>) in the composition can be, for example, ≤ <NUM> mass%, or <NUM>-<NUM> mass%.

One embodiment of the present invention is described in more detail by means of the Examples.

A solution of tetrafluorooxetane (<NUM> wt% chloroform solution, <NUM>, <NUM> mol) in ethanol (<NUM>) was added dropwise over <NUM> hour to a suspension of sodium iodide (<NUM>, <NUM> mol) in ethanol (<NUM>) under ice cooling. After dropwise addition, the temperature was raised to <NUM>, and the mixture was stirred under heating for <NUM> hours. The resulting reaction mixture (internal temperature: <NUM>) was filtered using a filter material (paper product, average pore diameter: <NUM>) and a filter aid (Celite (trademark), average particle size: <NUM>-<NUM>), and ethanol was distilled off to obtain ICH<NUM>CF<NUM>COOEt (yield: <NUM>%).

<FIG> and <FIG> show the <NUM>H-NMR spectrum and <NUM>F-NMR spectrum of ICH<NUM>CF<NUM>COOEt, respectively.

ICH<NUM>CF<NUM>COOEt was obtained by the same operation as in Example <NUM>, except that a liquid separation treatment was performed by the addition of water and diethyl ether to the reaction mixture in place of filtration.

ICH<NUM>CF<NUM>COOEt was obtained by the same operation as in Example <NUM> except that after filtration, water and diethyl ether were added to a filtrate to perform a liquid separation treatment.

The F ion content concentration in the products of Example <NUM>, Comparative Example <NUM>, and Example <NUM> was measured by the following method.

The following table shows the measurement results of the F ion concentration.

ICH<NUM>CF<NUM>COOMe (yield: <NUM>%) was obtained by the same operation as in Example <NUM> except that the ethanol used in Example <NUM> was changed to methanol.

BrCH<NUM>CF<NUM>COOEt (yield: <NUM>%) was obtained by the same operation as in Example <NUM> except that the sodium iodide used in Example <NUM> was changed to sodium bromide.

One hundred grams of the reaction mixture obtained in Example <NUM> was filtered under the conditions shown in Table <NUM>. The time required for the filtration was as shown in Table <NUM>.

Claim 1:
A method for producing a compound of formula (<NUM>):
<CHM>
wherein
R<NUM> is Cl, Br, I or SR, wherein R is H or a hydrocarbon group, and
R<NUM> is C<NUM>-<NUM>-alkyl, haloalkyl or aryl;
comprising the steps of
(A) reacting a compound of formula (<NUM>):
<CHM>
with a compound of the formula M(R<NUM>)n (<NUM>), wherein M is cation, n is an integer corresponding to the valence of M, and R<NUM> is as defined above, and a compound of the formula R<NUM>-OH (<NUM>), wherein R<NUM> is as defined above;
(B) separating, by filtration, a compound of the formula MFn (<NUM>), wherein M and n are as defined above, from the mixture obtained by the above reaction, and
(C) performing a liquid separation treatment on a filtrate obtained by the filtration.