JPS63295610A - Polymer containing n-fluoropyridinium salt - Google Patents

Abstract

PURPOSE:To provide the title polymer useful as a fluorinating agent for organic compounds, which is obtained by reacting a specific polymer containing pyridyl groups with fluorine and a Bronsted acid (metal salt). CONSTITUTION:A pyridyl group-containing polymer having repeating units of formula II obtained by polymerization of a vinylpyridine compound of formula I [wherein R<1-3> are each H, halogen, or lower (halo)alkyl; and R<4> is H or methyl], fluorine diluted to have 99.9-50vol.% with an inert gas of which molar amount is 1-10mol. per mol. of the repeating unit of formula II, and a Bronsted acid (metal salt) (e.g., sodium trifluoromethane-sulfonate) are reacted in the presence of 0.5-10mol. of a trapping agent (e.g., NaF) per mol. of the repeating unit of formula II in a liquid medium (e.g., acetonitrile) at -80-+40 deg.C to produce polymer containing N-fluoropyridinium salt having repeating units of formula III (wherein X<-> is a conjugated base of a Bronsted acid) and a number-average mol.wt. of 1,000 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polymer, and more particularly, to a novel polymer extremely useful as a fluorinating agent, in which R+, Rz, and R3 each represent a hydrogen atom, a halogen atom, or a lower (halo)alkyl atom. R4 represents a hydrogen atom or a methyl group; Xe is a conjugate base of a Brønsted acid.

Fluorine-containing compounds have recently attracted attention in the fields of medicine, agrochemicals, etc. as they exhibit unique physiological activities.

The synthesis of such fluorine-containing compounds often involves a fluorination reaction.

Several methods have been known as fluorination methods [for example, see "Fluorine Compounds - Their Chemistry and Applications" by Nobuo Ishikawa and Yoshibe Kobayashi, pp. 74-92, published by Kodansha Inc.], Shikashi, All conventional fluorination methods require the use of toxic, explosive and difficult-to-handle fluorinating agents, require harsh reaction conditions, and have low yields. was accompanied by considerable limitations.

The present inventors previously proposed an N-fluoropyridinium salt compound as a fluorinating agent that improves these drawbacks [Japanese Patent Application No. 125716/1983; Tetrahe
drone Letters 27-53271 (19
86); 1bid, λF, 4465 (198
6):11a11. CItes, Soe,
Jpn, 5 9-13625 (1986)], but this N-fluoropyridinium salt compound must be isolated by a recrystallization method during production, which makes the operation complicated and tends to result in a decrease in yield. When used as a fluorinating agent, for example, as shown in the following formula, an equimolar amount of pyridinium salt with the fluorinated product (RF) is produced as a by-product, so a step for separation is required. , leaving room for further improvement.

Therefore, the present inventors have conducted further research to resolve the above-mentioned difficulties, and have now found that the above-mentioned difficulties can be overcome by fixing N-fluoropyridinium salts to polymers as pendant side chains. Heading, the general formula (
The molecular weight containing the repeating unit represented by I) is 1000
The above N-fluoropyridinium salt-containing polymer has been provided.

The N-fluoropyridinium salt-containing polymer of the present invention does not require complicated purification operations such as recrystallization during its production, and can be easily isolated by simple operations such as filtration. , when it is used as a fluorinating agent,
The pyridinium salt-containing polymer produced as a by-product has various advantages such as being able to be separated from the fluorinated product very easily by a separate operation, and is very useful as a fluorinating agent for various organic compounds.

As used herein, the term "lower" means that the number of carbon atoms in the atomic group or compound to which the term is attached is 5 or less, preferably 3 or less.

Furthermore, "halogen atom" includes fluorine, chlorine, bromine, and iodine atoms. "Lower (halo)alkyl group" may be substituted with one or more halogen atoms,
A linear or branched lower alkyl group, such as methyl, ethyl, n-propyl, isopropyl, n
-butyl, isobutyl, 5ee-butyl, tart-butyl, n-pentyl, fluoromethyl, difluoromethyl, trifluoromethyl, trichloromethyl and the like.

Furthermore, examples of "Brönsted acids" include methanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, nitrobenzenesulfonic acid, dinitrobenzenesulfonic acid, l-snitrobenzenesulfonic acid, trifluoromethanesulfonic acid, and perfluorobutanesulfonic acid. acid, perfluorooctane sulfonic acid, l.
Sulfonic acids such as dichloromethanesulfonic acid, difluoromethanesulfonic acid, trifluoroethanesulfonic acid, fluorosulfonic acid, chlorosulfonic acid, monomethylsulfuric acid, sulfuric acid; perchloric acid, perbromic acid, periodic acid, chloric acid, bromine Halogen acids such as acids; Jpl*: Hydrogen chloride: HB F
4, HP F4, HP F*, HS
b F 4゜H8bFi, H8bCIs -H
AsFs, HBCIs F, HAIF4, H
3AlFm, H8i Fs, H2S i Fs
Examples include compounds of Lewis acids such as , and hydrogen halides. Therefore, the "conjugate base of a Brønsted acid" can be said to be the remaining portion of the Brønsted acid described above after removing the proton ( ) (Φ).

The polymers of the present invention may consist solely of one or more repeating units of formula (I), or may be derived from at least one repeating unit of formula (I) and the monomers described below. It can also be a copolymer consisting of at least one repeating unit. In the case of the latter copolymer, the formula (I
) repeating units account for at least 5 mol% of the copolymer, preferably 20 mol% or more, more preferably 30 mol%
It is preferable that the

In addition, the polymer of the present invention is generally preferably solid from the viewpoint of manufacturing and handling, and has a number average molecular weight of at least 1,000 or more, preferably 1,500 to 500,000, and more preferably 2,000 to 100,000. It is advantageous to be within the range. Furthermore, it is desirable that the polymer of the present invention is stable and does not deteriorate when handled, and for this purpose, Xθ, which is the conjugate base of the Brønsted acid, is advantageously one with poor nucleophilicity as illustrated.

The formula of the present invention (N containing a repeating unit represented by N)
- The fluoropyridinium salt-containing heavy body is a pyridyl group-containing polymer containing repeating units represented by R1, R2, R3, and R4 having the above meanings in the general formula. By reacting with the metal salt, the length can be increased to 1 m.

Examples of metal salts include alkali metal salts and alkaline earth metal salts.

It is usually desirable to carry out the reaction in a liquid medium, and examples of the reaction medium that can be used include acetonitrile, propionitrile, methylene chloride, chloroform, sulfolane, diethyl ether, tetrahydrofuran, and mixtures thereof. Fluorine used in the above reaction is highly reactive and reacts violently, so in order to appropriately control this, inert gas is used to
It is preferable to use it after diluting it to about 50% by volume.

Examples of inert gases that can be used for dilution include nitrogen, helium, argon, tetrafluoromethane, and sulfur hexafluoride. In order to perform the reaction with good yield,
It is generally convenient to use an amount of fluorine in an equimolar amount or more (preferably up to 10 times the molar amount) per mole of the repeating unit of formula (n), but the optimum amount is Depending on the introduction method, reaction temperature, type of reaction medium, reaction apparatus, and other conditions, it can be appropriately determined based on the fact that the substrate reacts with fluorine and disappears.

On the other hand, Brønsted acid or its metal salt can usually be used in an equimolar amount or an excess amount of up to about 5 times the molar amount per mole of the repeating unit of the above formula (U), but from an economical point of view, approximately It is preferred to use equimolar amounts.

The reaction temperature is generally in the range -80°C to +40°C, preferably -60°C to room temperature. Further, in the above reaction, hydrogen fluoride may be produced as a by-product, but the yield of the reaction may be improved if, for example, sodium fluoride or the like is present as a trapping agent for hydrogen fluoride, and it may be preferable to do so. The amount of sodium fluoride that can be used in the coexistence is generally from 0.5 mol to 10 mol per mol of the repeating unit of the above formula (n), but from the economical point of view, 0.5 mol is used.
A range of 5 moles is preferred.

The above reaction is generally carried out by dissolving or suspending a pyridyl group-containing polymer and a metal salt of Brønsted acid in a reaction medium, and then blowing a diluent gas of fluorine into the mixture, or This can be carried out by blowing a fluorine diluent gas into the containing polymer and then reacting it with a Brønsted acid.

The reaction proceeds almost quantitatively, and an N-fluoropyridinium salt-containing polymer in which the repeating units represented by formula (11) of the raw material are changed to the corresponding repeating units represented by formula (I) is produced. The resulting polymer can be isolated from the reaction mixture by a method known per se, for example, by adding a solvent insoluble to the N-fluoropyridinium salt-containing polymer to the reaction solution and precipitating it as a solid. .

, the formula (II
) The pyridyl group-containing polymer containing repeating units of formula (1) may be selected from R1, R2, R3, and R4 in the general formula depending on the desired N-fluoropyridinium salt-containing polymer having a large number of repeating units of formula (1). has the above-mentioned meaning, by polymerizing one or more of the vinyl pyridine compounds represented by, or by co-polymerizing at least one of the vinyl and lysine compounds with other copolymerizable ethylenically unsaturated monomers. It can be produced by polymerization.

(Co)polymerization is a solution polymerization method, a bulk polymerization method, which is known per se.
It can be carried out using emulsion polymerization method or suspension polymerization method [edited by the Chemical Society of Japan, New Experimental Chemistry Course 19, Polymer Chemistry [■
], see Maruzen (published in 1978)].

Examples of the vinylpyridine compound of the above formula (III) include: vinylpyridine, i.e., 4-vinylpyridine, 3-vinylpyridine, and 2-vinylpyridine; 4-methyl-2-vinylpyridine, 4-vinylpyridine, Methyl-3-vinylpyridine, 6-methyl-2-vinylpyridine, 5-methyl-3-vinylpyridine, 2-methyl-4-vinylpyridine, 3-1-lifluoromethyl-2
-vinylpyridine, 6-fluoromethyl-2-vinylpyridine, 6-cyfluoromethyl-2-vinylpyridine,
3.6-dimethyl-2-vinylpyridine, 2.6-dimethyl-4-vinylpyridine, 4,6-dimethyl-2-vinylpyridine, 2.4.6-dimethyl-3-vinylpyridine, 5-ethyl-2-vinylpyridine , 5-ethyl-3-vinylpyridine, etc., lower (halo)alkylvinylpyridine: 3-chloro-2-vinylpyridine, 3-chloro-6-vinylpyridine, 2-chloro-4-vinylpyridine, 2-chloro -6-vinylpyridine, 3-chloro-5-vinylpyridine, 2.5-dichloro-5-vinylpyridine, 2.6-dichloro-4-vinylpyridine, 3
-Fluoro-2-vinylpyridine, 5-fluoro-2-
vinylpyridine, 3-fluoro-4-vinylpyridine,
halobinylpyridine such as 3-bromo-6-vinylpyridine, 3,5-difluoro-2-vinylpyridine; 2-
Chloro-4-methyl-vinylpyridine, 2-chloro-6
-Methyl-4-vinylpyridine, 2.0-dichloro-4
lower alkyl-substituted halobinylpyridines such as -methyl-3-vinylpyridine; isopropenylpyridine, i.e. 2-isopropenylpyridine, 3-impropenylpyridine and 11-yne-10benylpyridine; 2-methyl-
6-(isopropenyl)pyridine, 3-methyl-6-(
, isopropenyl)pyridine, 2,6-cymethyl-4-
Lower alkyl-substituted (isopropenyl)pyridine such as (isopropenyl)pyridine; 3-chloro-6-(isopropenyl)pyridine, 3-fluoro-6-(isopropenyl)pyridine, 3-bromo-6-(impropenyl) Halo(isopropenyl)pyridine such as pyridine.

Among these, preferable examples include vinylpyridine, methylvinylpyridine, dimethylvinylpyridine, chlorovinylpyridine, dichlorovinylpyridine, (trifluoromethyl)vinylpyridine, and isopropenylpyridine.

On the other hand, the monomer that can be copolymerized with the above vinylpyridine compound is not particularly limited as long as it contains an ethylenically unsaturated bond, and any ethylenically unsaturated monomer can be used. However, some typical examples are as follows.

(a) Vinyl aromatic compounds, such as styrene, α-methylstyrene, α-chlorostyrene, p-chlorostyrene, divinylbenzene, vinylnaphthalene, and the like.

(b) (Meth)acrylic acid derivatives For example, (meth)acrylic acid C such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, decyl acrylate, etc.
2-C1° alkyl ester; acrylonitrile, methacrylonitrile; acrylamide, methacrylamide; acrolein, α-methylacrolein, etc.

(C) Olefins, such as ethylene, chlorethylene, dichloroethylene, fluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, tetrachloroethylene, propylene, and the like.

(d) Vinyl ethers, such as vinyl methyl ether, vinyl ethyl ether, vinyl 10 vinyl ether,
Vinyl butyl ether, vinyl octyl ether, etc.

(e) Others, vinyl acetate, allyl alcohol,
Allyl methyl ether, maleic anhydride, 1 vinyl-2
-Pyrrolidine etc.

The resulting pyridyl group-containing copolymer may be any type of alternating copolymer, irregular copolymer, or block copolymer, and the vinylpyridine compound of formula (1) may be, for example, cellulose, Cellulose acetate, polyesters, polyamides, polyethers, obtained by (co)polymerization of the above ethylenically unsaturated monomers
It may be grafted onto the polymer backbone, or block polymerization may be performed.

The pyridyl group-containing polymer containing the repeating unit of formula (II) is the desired N-
Formula (I) desired for fluoropyridinium salt-containing polymers
, i.e. at least 5 mol %, preferably 20 mol % or more, more preferably 3 mol %.
Contains 0 mol% or more of repeating units of formula (n). The number average molecular weight also corresponds to the target polymer, and it is desirable that the number average molecular weight is 500 or more, preferably 800 to 500,000, and more preferably 1,000 to 100,000.

In addition, in order to convert the pyridyl group-containing polymer containing the repeating unit of the formula (n) in a high yield into the N-fluoropyridinium salt-containing polymer containing the repeating unit of the formula (n), the pyridyl group-containing polymer containing the repeating unit of the formula (n) is used. Some solubility in the reaction solvent is desirable.

The N-fluoropyridinium salt-containing polymer provided by the present invention contains an active fluorine atom and is useful as an easy-to-handle fluorinating agent, for example, for the fluorination of aromatic arsenic compounds. be.

Next, the present invention will be further explained with reference to Examples.

Example 1 Poly(2-vinylpyridine) 10 mmol in terms of 1.05yC monomer, commercially available from Aldrich, glass transition temperature<T9) 104°C, number average molecular weight 3°18X10
2),) Sodium trifluoromethanesulfonate (Tf
ONa) 1.72g (10mm.

l), 1 g of sodium fluoride and anhydrous acetonitrile--1----------------m=10 m
1 to the mixture of F 2 /
N2 mixed gas (1/9) was introduced at a flow rate of 40 ml/min until the reaction solution became a homogeneous solution.Next, after stirring using Celite, ether was added to the filtrate, and the N of the product was A polymer containing -fluoropyridinium salt was formed as a white precipitate, and after separation and drying, 2.63 g of a polymer containing N-fluoropyridinium triflate was obtained. Its physical property values are shown below.

Decomposition point: 180°C 1”F-NMR (CD, CFCI in CN, internal standard,
ppm) knee 37.5 (NF, bs) 78.25 (CF3, s) 111 NMR (CD, in CN, δ) two 8.8-9.5 (Ha, m) 8, 4-8. 8 (He, m)7.6
~8.4 (Hb, Hd, m)1.5~2.5 (
CHCH2, m) rR (Nujol on NaCl plate, cm
-'): 3300.3100, 1640, 1620.1
240.1160.1100 To Example 2・5 The same procedure as in Example 1 was carried out using the same poly(2-vinylpyridine) used in Example 1 and the metal salt of Bronsted acid shown in Table 1 below. Various N-fluoropyridinium salt-containing polymers were synthesized under reaction conditions. The results are shown in Table 1 below.

Example 6 Poly(2-vinylpyridine) 1.05fI (lommol in terms of monomer, commercially available from Aldrich, glass transition temperature (Tg) 104°C, number average molecular weight 3.18X
10”), 1 g of NaF and 1 g of anhydrous acetonitrile
Add F2/N to 0ml of the mixed solution while stirring at -40℃.
2 mixed gas (7/92) was introduced at a flow rate of 71mff1/min, and the amount of eF2 used was 1゜mrn o I0
After the reaction solution was filtered through Celite, 10 mmol of fluorosulfone # was added while stirring under cooling at -40°C. Thereafter, when ether was added to the reaction solution, the N-fluoropyridinium salt-containing polymer was precipitated, and by r, the dry fl-fluoropyridinium fluorosulfonate-containing polymer was 2.46! F was obtained. Its physical property values are shown below.

-35,0 (FSOz, 8) = 37.5 (NF, bs) 'H-NMR (CD, in CN, δ): 8.8-9.5 (Ha, tn) 8, 4-8. 8 (Hc, m)7
．． 7-8.4 (Hb, Hd, nt) 1.5-2.5
(CHCHt,m>Example 7 2-vinyltridine-styrene copolymer Aldric
Company H city version, styrene content 30%, number average molecular weight 6.
83
After adding to 0 mN, F2 was added while stirring under cooling at -40°C.
/N* (1:9) mixed gas was introduced at 15.21 times (Fz, 68 mmo 1), and the reaction solution became a homogeneous solution. Thereafter, 7 mmol of trifluoromethanesulfonic acid (TfOH) was added at that temperature, and the mixture was stirred for 10 minutes.

When ether (30 rnj. The physical property values are shown below.

Decomposition point: 200℃ 'F-NMR (CFCl3 internal standard in CDsCN,
pp detective) knee 37, 5 (NF, b s
)77, 85 (CH3, s) -■-to JMR (in CD3CN, δ): 8°9
~9.5 (Ha, m> 8.45~8.9 (Hd, m> 7.7~8.45 (Hb, Hc, tn) 668~7
, 5 (phenyl nuclear hydrogen, m) IR (Nuj on NaCI plate
ol, cnt-'): 3300.1620.1010.
720 Reference Example 1 54 mg (0.55 mmo 1 ) of phenol, 0.40 fI (0.63 mmol as N-fluoropyridinium salt) of the N-fluoropyridinium salt-containing polymer obtained in Example 7, and anhydrous 1. After the reaction, a mixture of 2 ml of 1,2-trichloroethane was stirred at 100°C for 14 hours under a nitrogen atmosphere, and the pyridinium hydride salt polymer present as a white precipitate was removed by filtration, and the filtrate was quantified by gas chromatography. The conversion rate of phenol was 52%, 0-fluorophenol, p-
The conversion yields of fluorophenol and 2,4-difluorophenol were 60%, 26%, and 3%, respectively.
Met.

Claims (1)

[Claims] General formula ▲ Numerical formula, chemical formula, table, etc. ▼ In the formula, R^1, R^2 and R^3 each represent a hydrogen atom, a halogen atom or a lower (halo)alkyl group; ^4
represents a hydrogen atom or a methyl group; X^■ is a conjugate base of Bronsted acid; An N-fluorobiridinium salt-containing polymer having a molecular weight of 1000 or more and containing a repeating unit represented by the following.