WO2016197386A1

WO2016197386A1 - Preparation method and use of dialkyl phosphinic acid compounds

Info

Publication number: WO2016197386A1
Application number: PCT/CN2015/081339
Authority: WO
Inventors: 姚强; 赵月英; 唐天波
Original assignee: 中国科学院宁波材料技术与工程研究所
Priority date: 2015-06-12
Filing date: 2015-06-12
Publication date: 2016-12-15

Abstract

Disclosed is a preparation method for dialkyl phosphinic acid compounds. In the presence of a free radical initiator and a mercapto compound, phosphinic acid compounds react with olefins to prepare the dialkyl phosphinic acid compounds. The method is mild in reaction conditions, easy to operate, short in reaction time, high in the rate of conversion and high in product purity.

Description

Preparation method of dialkyl phosphinic acid compound and application thereof

Technical field

The present application relates to a method for preparing a dialkylphosphinic acid compound, and belongs to the field of preparation of organophosphorus compounds.

Background technique

Dialkylphosphinic acid and its salts have been widely used in the fields of flame retardant, mineral flotation and solvent extraction, and have important social and economic value. Their preparation methods have been widely concerned. So far, there have been many reports on the preparation methods of dialkylphosphinic acid and its salts. The most practical application method is to generate PC bonds by radical addition to olefins through compounds containing PH structure. Reaction.

U.S. Patent 2,579,793 discloses a process for the formation of P-C bonds by a free radical reaction of a compound containing a P-H bond and an olefin. This patent discloses the preparation of dialkylphosphinic acids in the presence of a free radical initiator using hypophosphorous acid and an olefin as starting materials. The results show that the yield of the dialkylphosphinic acid is very low.

U.S. Patent 4,374,780 reports the preparation of bis(2,4,4-trimethylpentyl)phosphinic acid. Using phosphine and diisobutylene as raw materials, in the presence of a free radical initiator, a dialkylphosphine is formed, and the dialkylphosphine is further oxidized by hydrogen peroxide to obtain bis(2,4,4-trimethylpentyl). Hypophosphonic acid. This method is difficult to industrialize due to the use of highly toxic phosphine, and the reaction requires high pressure.

U.S. Patent 7,049,463 reports an improved process for the preparation of bis(2,4,4-trimethylpentyl)phosphinic acid. The bis(2,4,4-trimethylpentyl)phosphinic acid is directly prepared from hypophosphorous acid or a salt thereof and diisobutylene as a raw material in the presence of a radical initiator. The method needs to be carried out under high pressure and the reaction time is long. It is necessary to remove a large amount of by-product mono(2,4,4-trimethylpentyl)phosphinic acid.

In view of the above, it is necessary to provide a process for preparing a dialkylphosphinic acid or a salt thereof which has mild reaction conditions, simple operation, short reaction time, high conversion rate, and high product purity.

Summary of the invention

According to an aspect of the present application, there is provided a method for preparing a dialkylphosphinic acid compound, which has the advantages of mild reaction conditions, simple operation, short reaction time, high conversion rate, high product purity, and the like, and overcomes the current dioxane. The preparation process of the phosphinic acid compound has the disadvantages of slow reaction rate, low conversion rate, many side reactions, and harsh reaction conditions.

The method for producing a dialkylphosphinic acid compound is characterized in that a diphosphinic acid compound is reacted with an olefin in the presence of a radical initiator and a thiol group-containing compound to prepare a dialkylphosphinic acid compound.

Preferably, the dialkylphosphinic acid compound is at least one selected from the group consisting of compounds having a chemical structural formula of the formula I, wherein the hypophosphorous acid compound is selected from the group consisting of compounds having the chemical structural formula shown in Formula II. At least one of:

Wherein, the number of carbon atoms in R ₁₁ and R ₁₂ is not more than 74; R ₁₁ and R ₁₂ are each independently selected from an alkyl group or an aralkyl group;

M ⁿ⁺ represents a cation having a valence of +n.

Preferably, the number of carbon atoms in R ₁₁ and R ₁₂ does not exceed 30, respectively. Further preferably, the number of carbon atoms in R ₁₁ and R ₁₂ does not exceed 18, respectively.

Preferably, 1 ≤ n ≤ 4, n is a positive integer.

Preferably, Mn ^{+ is} selected from at least one of H ⁺ , NH ₄ ⁺ , and metal ions. Further preferably, Mn ⁺ is at least one selected from the group consisting of H ⁺ , NH ₄ ⁺ , an alkali metal ion, and an alkaline earth metal ion.

The alkyl group is a group formed by the loss of any one hydrogen atom on the alkane molecule; the alkane includes a linear alkane, a branched alkane, a cycloalkane, a cycloalkane having an alkyl substituent. For example, a cyclopentyl group formed by losing one hydrogen atom on cyclopentane, a p-methylcyclohexyl group formed by losing one hydrogen atom in the para position of methylcyclohexane, and the like. The aralkyl group is a group formed by the loss of a hydrogen atom on an alkyl group on the molecule of the aryl-substituted alkane compound.

Preferably, the number of carbon atoms in the olefin does not exceed 74. Further preferably, the number of carbon atoms in the olefin does not exceed 30. Further preferably, the number of carbon atoms in the olefin does not exceed 18.

Preferably, the olefin is selected from at least one of a linear olefin, an aryl-substituted linear olefin, a branched olefin, an aryl-substituted branched olefin, a cyclic olefin, and an aryl-substituted cyclic olefin. The aryl-substituted linear olefin, the aryl-substituted branched olefin, and the aryl-substituted cyclic olefin refer to a compound in which at least one hydrogen atom of a linear olefin, a branched olefin, or a cyclic olefin is substituted with an aryl group, respectively.

Preferably, the olefin is selected from the group consisting of ethylene, propylene, butene, isobutylene, pentene, isoamylene, hexene, isohexene, octene, isooctene, decene, isodecene, 1-dodecene , diisobutylene, 2,7-dimethyloctene, 2,3-dimethylheptene, cyclopentene, cyclohexene, cyclooctene, 2-n-butylhexene, cyclohexylethylene, styrene And at least one of 3-phenylpropene. Further preferably, the olefin Selected from cyclopentene, cyclohexene, cyclooctene, isobutylene, isoamylene, isohexene, isooctene, isodecene, diisobutylene, 3,3-dimethyl-1-butene, 2,7 At least one of dimethyl octene, 2,3-dimethylheptene, and 2-n-butylhexene.

Preferably, the molar ratio of the olefin to the hypophosphorous compound is from 1 to 10:1. Further preferably, the molar ratio of the olefin to the hypophosphorous compound is from 2.5 to 6:1.

The thiol-containing compound contains one or more thiol groups. Preferably, the mercapto group-containing compound is selected from the group consisting of a mercaptan compound, a sulfur phenol compound, a mercapto group-containing carboxylic acid compound, a mercapto group-containing carboxylate compound, a mercapto group-containing carboxylate compound, and a mercapto group-containing compound. At least one of amino acid compounds.

Preferably, the thiol compound is selected from the group consisting of a compound formed by substituting at least one hydrogen atom of an alkane molecule with a mercapto group, and a compound formed by substituting at least one hydrogen atom on the non-substituent of the substituted alkane compound molecule with a mercapto group. The substituted alkane compound is a compound formed by substituting at least one hydrogen atom of an alkane molecule with at least one of a halogen, a hydroxyl group, an aldehyde group, a ketone group, an acyl group, an amino group, an aryl group, and a heteroaryl group. A compound formed by substituting at least one hydrogen atom of an alkane molecule with a mercapto group, such as a methyl mercaptan formed by substituting a hydrogen atom on a methane molecule with a mercapto group. a compound formed by substituting at least one hydrogen atom of a non-substituent in an alkane compound molecule with a mercapto group, such as a 2-methylfuran molecule formed by furan replacing a hydrogen atom in methane, wherein a hydrogen atom on the non-furanyl group is replaced by a mercapto group The mercapto mercaptan formed.

Preferably, the thiophenolic compound is selected from a compound formed by substituting at least one of a hydrogen atom on an aromatic ring of an aromatic hydrocarbon molecule by a thiol group, and at least one of a hydrogen atom on an aromatic ring of the substituted aromatic hydrocarbon molecule is substituted by a thiol group, a compound formed by substituting at least one of a hydrogen atom bonded to a carbon atom on a heteroaromatic ring of a heteroaromatic ring compound by a mercapto group, or a heteropolycyclic ring compound At least one of the compounds formed by substituting at least one of the hydrogen atoms bonded to the carbon atom on the aromatic ring by a mercapto group. The substituted aromatic hydrocarbon is a compound formed by substituting at least one hydrogen atom of the aromatic hydrocarbon molecule with at least one of a halogen, a hydroxyl group, an aldehyde group, an acyl group, an amino group, and an alkyl group. The substituted heteroaromatic ring compound is a compound in which at least one hydrogen atom of the heteroaromatic ring compound molecule is substituted with at least one of a halogen, a hydroxyl group, an aldehyde group, an acyl group, an amino group, and an alkyl group. A compound formed by substituting at least one of hydrogen atoms on an aromatic ring of an aromatic hydrocarbon molecule with a mercapto group, such as a thiophenol formed by substituting a hydrogen atom on a benzene ring with a mercapto group. A compound formed by substituting at least one of the hydrogen atoms on the aromatic ring of the aromatic hydrocarbon molecule with a mercapto group, such as p-bromothiophenol formed on the benzene ring of the bromobenzene molecule by a sulfonate-substituted hydrogen atom substituted with a mercapto group. A compound formed by substituting at least one of a hydrogen atom bonded to a carbon atom on a heteroaromatic ring of a heteroaryl ring compound with a mercapto group, such as 2-mercaptoimidazole formed by substituting a hydrogen atom on a thiophene ring with a mercapto group.

Preferably, the mercapto group-containing carboxylic acid compound is one selected from the group consisting of a compound in which at least one hydrogen atom bonded to a carbon atom to a carbon atom is substituted with a mercapto group. A 3-mercaptopropionic acid formed by substituting a hydrogen atom on a propionic acid molecule with a thiol group.

Preferably, the sulfhydryl group-containing carboxylate compound is one selected from the group consisting of a compound in which at least one hydrogen atom bonded to a carbon atom to a carbon atom is substituted with a mercapto group. Sodium thioglycolate formed by the substitution of a hydrogen atom on a sodium acetate molecule by a thiol group.

Preferably, the mercapto group-containing carboxylic acid ester compound is one selected from the group consisting of a compound in which at least one hydrogen atom bonded to a carbon atom to a carbon atom is substituted with a mercapto group. For example, methyl 3-mercaptopropionate formed by substituting a hydrogen atom on a methyl propionate molecule by a mercapto group; methyl mercaptoacetate formed by substituting a hydrogen atom on a methyl acetate molecule with a mercapto group.

Preferably, the amino group-containing compound having a mercapto group is selected from the group consisting of the chemical formula represented by formula III a monobasic acid salt of a compound and/or a compound having the chemical formula of formula III:

Wherein m is selected from any positive integer between 1 and 5;

R _{31 is} selected from -OH, -NH ₂ , -NHCH ₂ COOH or -O ^- (Q ^z+ ) _1/z ; wherein Q ^z+ is a cation representing a valence of +z;

R _{32 is} selected from H or —COR ₃₂₁ ; and R _{321 is} selected from an alkyl group having 1 to 10 carbon atoms.

Preferably, m is 1 or 2.

Preferably, the monobasic acid salt of the compound having the chemical structural formula of formula III is the hydrochloride salt of a compound having the chemical structural formula of formula III.

Preferably, the thiol-containing compound is selected from the group consisting of a compound having a chemical structural formula of the formula IV and/or a monobasic acid salt of a compound having the chemical structural formula of the formula IV:

Wherein R ₄₁ and R _{43 are} independently selected from hydrogen and an alkyl group having 1 to 10 carbon atoms;

R _{42 is} selected from a hydroxyl group, an alkoxy group, an aryloxy group, an aralkyloxy group, —NH ₂ , —NHCH ₂ COOH or —O ^— (Q ^z+ ) _1/z ; wherein Q ^z+ represents a valence state of +z valence Cation

k=0 or 1, p=1 or 2, and k+p=2; y=0 or 1;

0 ≤ x ≤ 15, and x is an integer.

Preferably, 1 ≤ z ≤ 4, n is a positive integer.

Preferably, Q ^{z+ is} selected from at least one of NH ₄ ⁺ and metal ions. Further preferably, Q ^z+ is at least one selected from the group consisting of NH ₄ ⁺ , an alkali metal ion, and an alkaline earth metal ion.

Preferably, the thiol-containing compound is selected from the group consisting of 2-mercaptoethanol, 3-mercapto-1-propanamine, 2-mercaptoethanesulfonic acid, 1-mercapto-2-propanone, methyl mercaptan, ethyl mercaptan, and propyl mercaptan. , butyl mercaptan, pentyl mercaptan, hexyl mercaptan, heptane thiol, octyl thiol, hydrazine thiol, thiol thiol, dodecyl mercaptan, tetradecyl mercaptan, hexadecane thiol, n-octadecyl thiol, Isooctyl mercaptan, sec-butyl mercaptan, tert-butyl mercaptan, cyclopentyl mercaptan, cyclohexyl mercaptan, benzyl mercaptan, 4-bromobenzyl mercaptan, mercapto mercaptan, ethanedithiol, 1,3- Propanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, m-dibenzylthiol, L-cysteine, L-cysteine hydrochloride, L-cysteine Methyl ester hydrochloride, L-cysteine ethyl ester hydrochloride, DL-cysteine, DL-cysteine hydrochloride, DL-cysteine methyl ester, DL-cysteine Methyl ester hydrochloride, DL-homocysteine, L-homocysteine, N-acetyl-L-cysteine, N-acetyl-L-cysteine methyl ester, N -acetyl-L-cysteine ethyl ester, N-methylcysteine, N-ethylcysteine, L-cysteinyl glycine, methyl thioglycolate, ethyl thioglycolate, thiol Amyl acetate, Hexyl hexyl acetate, isooctyl thioglycolate, heptyl thioglycolate, isodecyl thioglycolate, cetyl thioglycolate, benzyl thioglycolate, 2-butoxyethyl thioglycolate, sodium thioglycolate, Calcium thioglycolate, ammonium thioglycolate, lithium thioglycolate, 3-mercaptopropionic acid, potassium 3-mercaptopropionate, ammonium 3-mercaptopropionate, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, 3- Propyl mercaptopropionate, butyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate, decyl 3-mercaptopropionate, 2-mercaptopropionic acid, sodium 2-mercaptopropionate, 2-mercaptopropionate Ester, ethyl 2-mercaptopropionate, 2-mercaptobutyric acid, ethyl 3-mercaptobutyrate, 2-mercapto-acetamide, 1,4-butanediol bis(mercaptoacetate), decyl succinic acid , thiophenol, 2-mercaptothiophene, 2-mercaptoimidazole, 2-mercapto At least one of benzimidazole and 2-mercaptobenzothiazole. Further preferably, the thiol-containing compound is selected from the group consisting of L-cysteine hydrochloride, L-cysteine methyl ester hydrochloride, L-cysteine ethyl ester hydrochloride, DL-cysteine Acid, DL-cysteine hydrochloride, DL-cysteine methyl ester, DL-cysteine methyl ester hydrochloride, DL-homocysteine, L-homocysteine, N-acetyl-L-cysteine methyl ester, N-acetyl-L-cysteine ethyl ester, N-methylcysteine, N-ethylcysteine, L-cysteine Aminoacyl glycine, methyl thioglycolate, ethyl thioglycolate, amyl thioglycolate, hexyl thioglycolate, isooctyl thioglycolate, heptyl thioglycolate, isodecyl thioglycolate, cetyl thioglycolate, fluorenyl Benzyl acetate, 2-butoxyethyl thioglycolate, sodium thioglycolate, calcium thioglycolate, ammonium thioglycolate, lithium thioglycolate, 3-mercaptopropionic acid, potassium 3-mercaptopropionate, ammonium 3-mercaptopropionate Methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, propyl 3-mercaptopropionate, butyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate, decyl 3-mercaptopropionate, 2 - mercaptopropionic acid, sodium 2-mercaptopropionate, methyl 2-mercaptopropionate, 2- At least one of ethyl mercaptopropionate, 2-mercaptobutyric acid, ethyl 3-mercaptobutyrate, and 2-mercapto-acetamide.

Preferably, the molar ratio of the thiol-containing compound to the hypophosphorous compound is from 0.5 to 100:100. Further preferably, the molar ratio of the thiol group-containing compound to the hypophosphorous acid compound is from 2 to 50:100. Still more preferably, the molar ratio of the thiol-containing compound to the hypophosphorous compound is from 3 to 25:100.

The radical initiator is at least one selected from the group consisting of an azo initiator, a peroxide initiator, and a photoinitiator.

Further preferably, the radical initiator is at least one selected from the group consisting of azo initiators. The azo initiator is a cationic azo initiator and/or a non-cation azo initiator. Preferably, the azo initiator is selected from the group consisting of azobisisobutyronitrile, azobisisoheptonitrile, azobis Dimethyl butyrate, azoisobutylcyanocarboxamide, 4,4' azobis(4-cyanovaleric acid), 2,2'-azobis(2-methylbutyronitrile), 2, At least one of 2'-azobis(2-amidinopropane) dihydrochloride and 2,2'-azobisisobutylphosphonium dihydrochloride.

Preferably, the peroxide-based initiator is an inorganic peroxide and/or an organic peroxide free radical initiator. Further preferably, the peroxide-based initiator is selected from the group consisting of hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium persulfate, sodium percarbonate, benzoyl peroxide, di-tert-butyl peroxide, t-butyl At least one of perbenzoic acid ester and peracetic acid.

Preferably, the free radical initiator is selected from the group consisting of azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-methylbutyronitrile) ), 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobisisobutylphosphonium dihydrochloride, hydrogen peroxide, ammonium persulfate, potassium persulfate And at least one of sodium persulfate, sodium percarbonate, benzoyl peroxide, di-tert-butyl peroxide, t-butyl perbenzoate, and peracetic acid.

Preferably, the molar ratio of the radical initiator to the hypophosphorous compound is from 0.5 to 100:100. Further preferably, the molar ratio of the radical initiator to the hypophosphorous compound is from 2 to 50:100. Still more preferably, the molar ratio of the radical initiator to the hypophosphorous compound is from 5 to 35:100.

Preferably, the reaction is carried out at a reaction temperature of from 20 ° C to 180 ° C. A further preferred reaction temperature is from 50 ° C to 160 ° C. Still more preferably, the reaction temperature is from 60 ° C to 145 ° C.

The technical solution of the present application greatly shortens the reaction time. Preferably, the reaction time does not exceed 50 hours. Further preferably, the reaction time does not exceed 40 hours. Still more preferably, the reaction time does not exceed 33 hours.

Preferably, the radical initiator, a thiol-containing compound, a hypophosphorous compound, and an alkene The molar ratio of hydrocarbons is:

Free Radical Initiator: Compound containing a mercapto group: hypophosphorous compound: olefin = 0.5 to 100: 0.5 to 100: 100: 100 to 1000.

Further preferably, the molar ratio of the radical initiator, the thiol group-containing compound, the hypophosphorous compound and the olefin is:

Free radical initiator: a compound containing a mercapto group: a hypophosphorous compound: an olefin = 2 to 50: 2 to 50: 100: 200 to 600;

Still more preferably, the molar ratio of the radical initiator, the mercapto group-containing compound, the hypophosphorous compound, and the olefin is:

Free radical initiator: a compound containing a mercapto group: a hypophosphorous compound: an olefin = 5 to 35: 3 to 25: 100: 250 to 600.

As an embodiment, a reaction system for preparing a dialkylphosphinic acid compound further contains a solvent, and the reaction is carried out in a solvent. Preferably, the solvent is selected from at least one of an organic carboxylic acid, an alcohol compound, an ester compound, and water. Further preferably, the solvent is water and/or an organic carboxylic acid. Still more preferably, the organic carboxylic acid is selected from at least one of formic acid, acetic acid, propionic acid, and isooctanoic acid.

In the present application, the reaction for preparing a dialkylphosphinic acid compound can be carried out under normal pressure or under high pressure.

In the technical solution of the present application, the method of adding a thiol-containing compound, a radical initiator, an olefin, and a hypophosphorous compound is not particularly required, and may be added all at once before the reaction, or may be batched during the reaction. Add or continuously add dropwise. Preferably, the thiol-containing compound and the radical initiator are added in batchwise or continuously dropwise, and the reaction is added during the reaction. Should be system.

After completion of the reaction, the thiol group-containing compound can be removed by a conventional method in the art, such as at least one of a water washing method, an alkali washing method, an acid washing method, a distillation method, an adsorption method, and an oxidation method.

As a preferred embodiment, the steps for preparing the dialkylphosphinic acid compound are as follows:

a) In the reaction vessel containing the solvent, 0 to 99% of the total amount of the phosphoric acid compound, 0 to 100% of the total amount of the compound containing a mercapto group, 0 to 100% of the total amount of the radical initiator, and the total amount of the olefin 0 to 100%;

b) the remaining hypophosphorous compound (100% to 1% of the total amount of the hypophosphorous compound), the remaining thiol-containing compound (100% to 0 of the total amount of the thiol-containing compound), and the remaining radical initiator ( 100% to 0) of the total amount of the radical initiator, and the residual olefin (100% to 0 of the total amount of the olefin) are continuously or batchwise added to the reaction vessel, and reacted at a temperature of 30 to 150 ° C;

c) after completion of the reaction, the thiol-containing compound, excess solvent and olefin are removed by at least one of oxidation, water washing, alkali washing, vacuum distillation or vacuum drying to obtain a high purity dialkylphosphinium. Acid compounds.

The present application accelerates the formation rate of monoalkylphosphinic acid compounds and dialkylphosphinic acid compounds by adding a mercapto group-containing compound to the reaction system. An olefin of the formula R ₁ R ₂ C=CR ₃ R ₄ (wherein R ₁ , R ₂ , R ₃ , and R ₄ each have no more than 18 carbon atoms, and R ₁ , R ₂ , R ₃ , and R ₄ respectively An alkali metal salt which is independently selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, heteroaryl or substituted heteroaryl) and hypophosphorous acid (M ⁿ⁺ in formula II is a monovalent alkali metal ion) For example, the principle of formation of dialkylphosphinic acids is as follows:

The free radical initiator X generates a radical R·, as shown by the chemical formula of formula V:

X→R· Formula V

The free radical R· captures the hydrogen of the hypophosphorous compound to form a hypophosphoric acid radical, as shown in the chemical formula:

The addition of hypophosphoric acid radicals to R ₁ R ₂ C=CR ₃ R ₄ produces a carbon-centered radical, as shown in formula VII:

Formula VII is a reversible process in which, when a thiol-containing compound is present, the hydrogen atom in the thiol-containing compound promotes the reaction in the direction of formation of the monoalkylphosphinic acid compound, thereby accelerating the overall reaction rate, as in Formula VIII and The chemical structure shown in IX:

The monoalkylphosphinic acid compound continues to react to form a dialkylphosphinic acid compound.

According to still another aspect of the present application, a flame retardant comprising at least one of the dialkylphosphinic acid compounds prepared according to any of the above methods is provided.

According to still another aspect of the present application, there is provided a metal extractant characterized by comprising at least one of the dialkylphosphinic acid compounds prepared according to any of the above methods.

Preferably, the metal extractant is a cobalt extractant, a nickel extractant or a rare earth metal extractant. Further preferably, the rare earth metal extractant is a cerium extractant, a cerium extractant, a cerium extracting agent, a cerium extracting agent, a cerium extracting agent or a cerium extracting agent.

The beneficial effects of the technical solution described in the present application are:

In the process of synthesizing a dialkylphosphinic acid compound, the present invention can increase the reaction rate by adding a compound containing a mercapto group, and can suppress the formation of a by-product monoalkylphosphinic acid compound, and has a mild reaction condition. Short reaction time and high product purity.

detailed description

The present application is described in detail below with reference to the embodiments, but the application is not limited to the embodiments.

In the examples, nuclear magnetic resonance phosphorus spectrum ¹³ P-NMR was measured using an Avance 400 type nuclear magnetic resonance apparatus of Bruker.

In the examples, the purity of the diisobutylene used was 97% (containing 2,4,4-trimethyl-1-pentene 75.4%, and 2,4,4-trimethyl-2-pentene 21.6%).

Example 1

To a four-necked flask, 10.00 g of sodium hypophosphite monohydrate (0.0943 mol), 200 g of glacial acetic acid, and 31.76 g (0.283 mol) of diisobutylene were added, and after stirring, 0.31 g of azobisisobutyronitrile and 0.114 g of L were further added. - Cysteine. Heating and controlling the reaction temperature between 80 and 100 ° C, adding L-cysteine to the system every 6 hours, each time adding 0.171 g; and adding azo to the system every 3 hours Diisobutyronitrile was added with 0.465 g of azobisisobutyronitrile each time. After reacting for 33 hours, the mixture was cooled and cooled, and the obtained product was analyzed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 86.6%, and the monoalkylphosphinic acid compound. The molar content in the phosphorus-containing product was 1.3%, and the molar ratio of the dialkylphosphinic acid compound to the monoalkylphosphinic acid compound was 66.6.

Example 2

To a four-necked flask, 10.00 g of sodium hypophosphite monohydrate (0.0943 mol), 200 g of glacial acetic acid, and 31.76 g (0.283 mol) of diisobutylene were added, and after stirring, 0.31 g of azobisisobutyronitrile and 0.100 g of 3 were further added. - mercaptopropionic acid. Heating and controlling the reaction temperature between 80 and 100 ° C, continuously adding a 9.10% acetic acid solution of 3-mercaptopropionic acid at a mass concentration of 9.10% to the four-necked flask; and adding to the system every 3 hours. Azobisisobutyronitrile was added with 0.465 g of azobisisobutyronitrile each time. After reacting for 27 hours, the mixture was cooled and cooled, and the obtained product was observed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 88.9%, and the monoalkylphosphinic acid compound. The molar content in the phosphorus-containing product was 0.7%, and the molar ratio of the dialkylphosphinic acid compound to the monoalkylphosphinic acid compound was 127.

Example 3

Add 10.00 g of sodium hypophosphite monohydrate (0.0943 mol), 200 g of glacial acetic acid and 31.76 g (0.283 mol) of diisobutylene to a four-necked flask, stir and dissolve, and then heat and control the reaction temperature between 80 and 100 ° C. A total of 13.50 g of a solution of methyl thioglycolate having a mass concentration of 9.10% was uniformly added to the four-necked flask; and azobisisobutyronitrile was added to the system every 3 hours, and 0.465 g of azo was added each time. Diisobutyronitrile. After reacting for 30 hours, the mixture was cooled and cooled, and the obtained product was observed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 92%, and there was no monoalkyl group in the phosphorus-containing product. A phosphinic acid compound.

Example 4

4.56 g of sodium hypophosphite and 1.028 g of methyl thioglycolate were dissolved in 11.4 g of acetic acid to prepare a solution A. To a four-necked flask, 12.00 g of sodium hypophosphite monohydrate, 80 g of glacial acetic acid, and 74.45 g of diisobutylene were added, and after stirring, 0.372 g of azobisisobutyronitrile and 0.120 g of methyl thioglycolate were further added. Heating and controlling the reaction temperature between 80 and 100 ° C, the solution A was uniformly added dropwise to the four-necked flask, and azobisisobutyronitrile was added to the system every 1.5 hours, and each time 0.465 g of the couple was added. Nitrogen diisobutyronitrile. After reacting for 15 hours, the mixture was cooled and cooled, and the obtained product was analyzed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 89.9%, and the monoalkylphosphinic acid compound. The molar content in the phosphorus-containing product was 1.3%, and the molar ratio of the dialkylphosphinic acid compound to the monoalkylphosphinic acid compound was 69.15.

The above product was transferred to a single-mouth bottle, 7.3 g of 30% by mass hydrogen peroxide solution was added, and stirred at 70 ° C for 40 min, and then 70 g of water was slowly added until two phases appeared, and the aqueous phase was removed. The organic phase was washed with 27 g of a 5% strength sodium hydroxide solution to remove the aqueous phase. The organic phase was acidified with 17 g of a 10% strength sulfuric acid solution to remove the aqueous phase. The organic phase was washed with 50 g of water and the aqueous phase was removed. The obtained organic phase was subjected to rotary distillation under vacuum to remove the volatile material to obtain a dialkylphosphinic acid compound, and the purity thereof was measured by ³¹ P-NMR, and the obtained dialkylphosphinic acid compound was found to have a purity of more than 91%. .

Example 5

To a four-port reactor, 10.00 g of sodium hypophosphite monohydrate (0.0943 mol), 200 g of glacial acetic acid and 31.76 g (0.283 mol) of diisobutylene were added, and after stirring, 0.31 g of azobisisobutyronitrile and 1.14 g were further added. L-cysteine. The reaction temperature was heated and controlled between 80 and 100 ° C, and azobisisobutyronitrile was added to the system every 1 hour, and 0.155 g of azobisisobutyronitrile was added each time. After reacting for 33 hours, the mixture was cooled and cooled, and the obtained product was analyzed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 70.0%, and the monoalkylphosphinic acid compound was obtained. The molar content of the phosphorus-containing product was 12.5%.

Example 6

10.00 g of sodium hypophosphite monohydrate (0.0943 mol), 200 g of glacial acetic acid and 19.85 g (0.236 mol) of 3,3-dimethyl-1-butene were added to a four-necked flask, stirred and dissolved, and heated to reflux. 0.00283 mol of azobisisobutyronitrile, after 2 hours of reaction, sample I was taken for ³¹ P-NMR measurement, and it was found that no dialkylphosphinic acid compound was formed, only a single alkyl group having a molar content of 2%. Phosphonic acid compounds. After the reaction was continued for 2 hours, sample II was taken for ³¹ P-NMR measurement, and the results still showed no formation of a dialkylphosphinic acid compound, and only a monoalkylphosphinic acid compound having a molar content of 3%. 0.00283 mol of methyl thioglycolate and 0.00283 mol of azobisisobutyronitrile were added separately. After 1 hour, sample III was taken for ³¹ P-NMR measurement. The results showed that no dialkylphosphinic acid compound was formed. A monoalkylphosphinic acid compound having a molar content of 18%. After 3 hours, sample IV was taken for ³¹ P-NMR measurement, and it was found that a dialkylphosphinic acid compound having a molar content of 17% and a monoalkylphosphinic acid compound having a molar content of 70%. 0.000943 mol of methyl thioglycolate and 0.000943 mol of azobisisobutyronitrile were separately added to the four-necked flask, and then 0.00283 mol of methyl thioglycolate and 0.00283 mol of azobisisobutyronitrile were added to the four-necked flask every 3 hours. After the reaction was continued for 18 hours, the mixture was cooled and cooled, and the obtained product was observed by ³¹ P-NMR. The result showed that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 69.0%, and the monoalkylphosphinic acid was obtained. The molar content of the compound in the phosphorus-containing product was 27.0%.

It is shown that the addition of a compound containing a mercapto group can greatly accelerate the rate of formation of the monoalkylphosphinic acid and ultimately greatly increase the rate of formation of the dialkylphosphinic acid.

Comparative example 1

The specific materials, amounts and ratios were the same as in Example 4 except that no methyl thioglycolate was added. The obtained product was detected by ³¹ P-NMR, and it was found that the molar content of the dialkylphosphinic acid compound in the phosphorus-containing product was 2.2%, and the molar content of the monoalkylphosphinic acid compound in the phosphorus-containing product was 38.8%; in addition, the product also has a molar content of 47.1%, unreacted hypophosphorous acid/sodium.

By comparing the data of Comparative Example 1 and Example 4, it can be seen that the addition of a compound containing a mercapto group to the reaction improves the phosphinic acid compound in a shorter reaction time than the technical solution in which the compound containing a mercapto group is not added. The conversion rate ensures the selectivity of the dialkyl hypophosphorous acid compound, thereby greatly increasing the yield of the dialkyl hypophosphorous acid compound per unit time. Further, in Example 4 using the technical solution of the present application, the content of the by-product monoalkylphosphinic acid compound was lower.

Example 7 as a metal extractant application

The extraction effect of the dialkylphosphinic acid compound obtained in Example 4 as a metal extractant was tested.

In this embodiment, the extraction rate is calculated as follows:

Extraction rate = (total moles of metal ions - moles of metal ions in the aqueous phase after extraction) / total moles of metal ions × 100%

The test procedure for extracting nickel is as follows: the dialkylphosphinic acid compound obtained in Example 4 is dissolved in n-hexane to obtain a n-hexane solution of a 10% by volume of a dialkylphosphinic acid compound; the obtained n-hexane solution is obtained. The mixture was mixed with water in a ratio of 1:1 by volume to obtain an extract. The extract was mixed with a nickel sulfate aqueous solution having a mass concentration of 5 g/L at room temperature and stirred for 5 minutes, and the pH of the aqueous phase was 6.0. The nickel ion content in the aqueous phase was determined by Perkin-Elmer's Optima Model 2100 inductively coupled plasma optical emission spectrometer (ICP), and the extraction yield was calculated to be 17%.

The test procedure for extracting cobalt is as follows: the dialkylphosphinic acid compound obtained in Example 4 is dissolved in n-hexane to obtain a n-hexane solution of a 10% by volume of a dialkylphosphinic acid compound; the obtained n-hexane solution The mixture was mixed with water in a ratio of 1:1 by volume to obtain an extract. The extract was mixed with a cobalt sulfate aqueous solution having a mass concentration of 1 g/L at room temperature and stirred for 5 minutes, and the pH of the aqueous phase was 4.0. The content of cobalt ion in the aqueous phase was determined by Perkin-Elmer's Optima Model 2100 inductively coupled plasma optical emission spectrometer (ICP), and the extraction yield was calculated to be 42%.

The above description is only a few examples of the present application, and is not intended to limit the scope of the application. However, the present application is disclosed in the preferred embodiments, but is not intended to limit the application, any person skilled in the art, Any changes or modifications made by the above-disclosed technical contents are equivalent to the equivalent embodiments, and are all technical solutions without departing from the scope of the technical solutions of the present application. Within the scope.

Claims

A process for producing a dialkylphosphinic acid compound, which comprises reacting a hypophosphorous compound with an olefin in the presence of a radical initiator and a thiol-containing compound to prepare a dialkylphosphinic acid compound.
The method according to claim 1, wherein the dialkylphosphinic acid compound is at least one selected from the group consisting of compounds having a chemical structural formula of the formula I, and the hypophosphorous acid compound is selected from the group consisting of At least one of the compounds having the chemical structural formula of Formula II:

Wherein, the number of carbon atoms in R 11 and R 12 is not more than 74; R 11 and R 12 are each independently selected from an alkyl group or an aralkyl group;

M n+ represents a cation having a valence of +n.
The process according to claim 1, wherein the olefin is selected from the group consisting of ethylene, propylene, butylene, isobutylene, pentene, isoamylene, hexene, isohexene, octene, isooctene, and decene. Isodecene, 1-dodecene, diisobutylene, 2,7-dimethyloctene, 2,3-dimethylheptene, cyclopentene, cyclohexene, cyclooctene, 2-positive Butyl hexene, cyclohexylethylene, styrene, 3-phenyl propyl At least one of the olefins.
The method according to claim 1, wherein the thiol group-containing compound is selected from the group consisting of a thiol compound, a thiophenol compound, a thiol group-containing carboxylic acid compound, a thiol group-containing carboxylate compound, and the like. At least one of a mercaptocarboxylic acid ester compound and a mercapto group-containing amino acid compound.
The method according to claim 1, wherein the thiol-containing compound is selected from the group consisting of L-cysteine hydrochloride, L-cysteine methyl ester hydrochloride, and L-cysteine. Ethyl ester hydrochloride, DL-cysteine, DL-cysteine hydrochloride, DL-cysteine methyl ester, DL-cysteine methyl ester hydrochloride, DL-homocysteine Acid, L-homocysteine, N-acetyl-L-cysteine methyl ester, N-acetyl-L-cysteine ethyl ester, N-methylcysteine, N-B Cysteine, L-cysteinyl glycine, methyl thioglycolate, ethyl thioglycolate, amyl thioglycolate, hexyl thioglycolate, isooctyl thioglycolate, heptyl thioglycolate, isodecyl thioglycolate , cetyl mercaptoacetate, benzyl thioglycolate, 2-butoxyethyl thioglycolate, sodium thioglycolate, calcium thioglycolate, ammonium thioglycolate, lithium thioglycolate, 3-mercaptopropionic acid, 3-mercapto Potassium propionate, ammonium 3-mercaptopropionate methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, propyl 3-mercaptopropionate, butyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate , 3-mercaptopropionate, 2-mercaptopropionic acid, 2-巯At least one of sodium propionate, methyl 2-mercaptopropionate, ethyl 2-mercaptopropionate, 2-mercaptobutyric acid, ethyl 3-mercaptobutyrate, and 2-mercapto-acetamide.
The production method according to claim 1, wherein the radical initiator is at least one selected from the group consisting of azo initiators.
The production method according to claim 1, wherein the reaction is carried out at a reaction temperature of from 20 ° C to 180 ° C; a preferred reaction temperature is from 50 ° C to 160 ° C; further preferred The reaction temperature is from 60 ° C to 145 ° C.
The method according to claim 1, wherein the radical initiator, the thiol group-containing compound, the hypophosphorus compound, and the olefin molar ratio are:

Free radical initiator: a compound containing a mercapto group: a hypophosphorous compound: an olefin = 0.5 to 100: 0.5 to 100: 100: 100 to 1000;

Preferably, the molar ratio of the radical initiator, the thiol group-containing compound, the hypophosphorous compound and the olefin is:

Free radical initiator: a compound containing a mercapto group: a hypophosphorous compound: an olefin = 2 to 50: 2 to 50: 100: 200 to 600;

Further preferably, the molar ratio of the radical initiator, the thiol group-containing compound, the hypophosphorous compound and the olefin is:

Free radical initiator: a compound containing a mercapto group: a hypophosphorous compound: an olefin = 5 to 35: 3 to 25: 100: 250 to 600.
A flame retardant comprising at least one of a dialkylphosphinic acid compound prepared by the method according to any one of claims 1 to 8.
A metal extractant characterized by containing at least one of the dialkylphosphinic acid compounds prepared by the method according to any one of claims 1 to 8.