阅读说明：本技术 一种硫氨酯生产过程中副产品2-巯基乙酸钠的利用方法 (Method for utilizing byproduct sodium 2-mercaptoacetate in thiourethane production process ) 是由 钟宏 黄小平 王帅 于 2019-09-04 设计创作，主要内容包括：本发明属于废水处理,具体公开了一种硫氨酯生产过程中副产品2-巯基乙酸钠的利用方法。该方法是利用硫氨酯生产工艺中的副产品2-巯基乙酸钠为原料,与卤代试剂进行反应,得到烷基硫醚基乙酸；烷基硫醚基乙酸与甲醇酯化得到烷基硫醚基乙酸甲酯,进一步与盐酸羟胺反应,得到烷基硫醚基乙基羟肟酸。该方法解决了硫氨酯工艺中副产品2-巯基乙酸钠回收难的问题,提高了副产品利用率,有利于环境保护。(The invention belongs to wastewater treatment, and particularly discloses a method for utilizing a byproduct, namely sodium 2-mercaptoacetate in a thiourethane production process. The method comprises the steps of reacting a byproduct, namely 2-sodium thioglycolate in a thiourethane production process, serving as a raw material with a halogenated reagent to obtain alkyl thioether-based acetic acid; and esterifying the alkyl thioether acetic acid with methanol to obtain alkyl thioether methyl acetate, and further reacting with hydroxylamine hydrochloride to obtain alkyl thioether ethyl hydroximic acid. The method solves the problem that the byproduct sodium 2-mercaptoacetate in the thiourethane process is difficult to recover, improves the utilization rate of the byproduct and is beneficial to environmental protection.)

1. a method for utilizing a byproduct, namely sodium 2-mercaptoacetate in the production process of thiourethane is characterized by comprising the following steps:

Step 1): carrying out substitution reaction on an aqueous solution of 2-sodium thioglycolate and a halogenated reagent with a structure shown in a formula I to obtain alkyl thioether sodium acetate with a structure shown in a formula II;

Step 2): acidifying the sodium alkyl thioether acetate to obtain alkyl thioether acetic acid with a structure shown in a formula III;

Step 3): carrying out esterification reaction on alkyl thioether acetic acid and methanol to obtain alkyl thioether methyl acetate with a structure shown in a formula IV;

Step 4): carrying out hydroximization reaction on alkyl thioether methyl acetate, hydroxylamine hydrochloride and sodium hydroxide to obtain alkyl thioether ethyl hydroximic acid with a structure shown in a formula V;

R¹-X

Formula I

Said R¹Is C₁～C₁₆Alkyl or C₃～C₁₆Cycloalkyl groups of (a); x is halogen; the alkyl or cycloalkyl group optionally contains phenyl, substituted phenyl, C₁～C₈At least one substituent of the alkoxy group of (1).

2. The method of claim 1, wherein R is¹Is ethyl, isopropyl, isobutyl, tert-butyl, benzyl, benzylethyl or cyclohexyl.

3. The utilization method according to claim 1, characterized in that:

The reaction conditions of the sodium 2-mercaptoacetate and the halogenated reagent in the step 1) are as follows: the reaction temperature is 30-120 ℃, the reaction time is 2-10 h, the dosage of the halogenated reagent is 0.9-1.5 times of the dosage of the 2-sodium thioglycolate substance, and the dosage of the sodium hydroxide is 0.5-3.5 times of the dosage of the 2-sodium thioglycolate substance.

4. The utilization method according to claim 1, characterized in that: the acid used for acidification in the step 2) is one of hydrochloric acid, sulfuric acid or nitric acid.

5. The utilization method according to claim 1, characterized in that: the esterification reaction conditions in the step 3) are as follows: the reaction temperature is 50-100 ℃, the reaction time is 1-6 h, and the molar ratio of the alkyl thioether-based acetic acid to the methanol is 1.0: 1.0-8, and the catalyst is concentrated sulfuric acid.

6. The utilization method according to claim 1, characterized in that: the hydroximization reaction conditions in the step 4) are as follows: the reaction temperature is 10-60 ℃, the reaction time is 2.5-6 h, the molar ratio of the alkyl thioether-based methyl acetate to the hydroxylamine hydrochloride to the sodium hydroxide is 1.0: 1.0-1.5, and the amount of solvent water is 10-100 mL of distilled water/0.1 mol of alkyl thioether-based acetic acid.

7. The utilization method according to any one of claims 1 to 6, wherein the sodium 2-mercaptoacetate is derived from sodium 2-mercaptoacetate which is a byproduct in a thiourethane production process:

the byproduct steps are as follows:

performing esterification reaction on xanthate with a structural formula VI, 2-chloroacetic acid and sodium carbonate, and then performing ammonolysis reaction on the xanthate with a structural formula VII and fatty amine with a structural formula VII to obtain thiourethane with a structural formula VIII and 2-sodium thioglycolate;

R³-NH₂

Formula VII

R²Is C₁～C₁₆Alkyl of (C)₆～C₁₆Aryl or C of₃～C₁₆A cycloalkyl group of the formulaAlkoxyalkyl of structure IX;

R⁴-O-R⁵-

Formula IX

In the formula IX, R⁴Is C₁～C₁₂Alkyl or C₆～C₁₂Aryl of (a); r⁵is C₁～C₆An alkylene group of (a);

R³Is C₁～C₈Alkyl group of (1).

8. the use according to claim 7, wherein the esterification reaction conditions are: the reaction temperature is 30-100 ℃, the reaction time is 0.5-5 h, and the molar ratio of the 2-chloroacetic acid to the alkylxanthate to the sodium carbonate is 1.0: 1.0-1.2: 0.4-1.0, and the amount of solvent water is 5-50 mL/0.1mol of 2-chloroacetic acid.

9. The utilization method according to claim 7, wherein the conditions of the ammonolysis reaction are: the reaction temperature is 20-90 ℃, the reaction time is 0.5-3 h, and the molar ratio of the xanthate to the fatty amine is 1.0:1.0 to 1.5.

10. The process as claimed in any of claims 1 to 9, characterized in that the alkyl thioether ethyl hydroxamic acid obtained is used as a metal ion extractant;

Preferably, the metal ions are iron ions, copper ions, nickel ions, ferrous ions or rare earth metal ions;

Preferably, in the extraction process, the ratio of the organic phase to the water phase is 1-2: 1-2; the extraction temperature is preferably 25-35 ℃.

Technical Field

The invention belongs to the field of waste water utilization, and relates to a method for utilizing a byproduct, namely sodium 2-mercaptoacetate in a thiourethane production process.

Background

The thiourethane is an important flotation collector and is relatively stable. In flotation practice, compared with traditional xanthate and xanthate, the collector has higher selectivity, and can realize flotation separation of minerals under a medium with lower pH, so that the collector is widely applied to sulfide flotation and is a sulfide flotation collector with high application value.

The synthesis method of thiourethane has more reports, wherein the method for performing chloroacetic acid esterification and then aminolysis on xanthate has the advantages of wide raw material source, simple process flow, easy control of production technology and the like, and is the main process for industrially producing thiourethane at present. It is characterized by that it uses xanthate, 2-chloroacetic acid and sodium carbonate to make esterification reaction to obtain alkyl xanthate carboxylate, then the alkyl xanthate carboxylate is reacted with fatty amine to obtain thiourethane product (Daohuayi, Wangmeisun, gold root and preparation of ethionamide [ J ]. modern chemical industry, 1999 (1): 27-29). In the actual production of the method, the technology produces the thiourethane product and also produces sodium thioglycolate which is present in wastewater. To use sodium thioglycolate, zhenghong et al used a mixture of dichloromethane and ether as an extractant to extract sodium thioglycolate from sodium thioglycolate aqueous solution (zhenghong, liuyao, junsu study of recovery of thioglycolate from thionocarbamate tail solution using mixed extractants [ J ]. nonferrous mining, 2006 (6): 17-18, 52); xuqinghua adopts a method of combining acidification, extraction and distillation to recover sodium thioglycolate in the tail liquid of thionocarbamate (Xuqinghua. experimental research on the extraction process of recovering thioglycolic acid from the tail liquid of thionocarbamate [ J ].2015 (12): 10-11).

the alkyl thioether acetic acid is a compound containing a carboxylic acid structure, and can be used as a fine chemical intermediate, an extracting agent and the like due to the carboxyl functional group. Ling Yong et al, which uses alkyl thioether acetic acid as a synthetic intermediate of antitumor drugs (Yong Ling, Xiaoolei Ye, Hui Ji, et al, Synthesis and evaluation of biochemical-sensitive derivatives of farnesyl thio-phenolic acid as anti-tumor agents, Bioorganic and Medicinal chemistry.2010,18: 3448-3456). The results of the extraction of palladium by phenylisothioureido acetic acid by goldenrain, et al show that the extraction of palladium by phenylisothioureido acetic acid is very good (goldenrain, li, et al. study on the performance and mechanism of extracting palladium by phenylisothioureido acetic acid [ J ]. university of zhongshan (natural science edition): 2002(2):57-59, 63).

Hydroximic acid is an important compound and can be used as a medical intermediate and a chelating agent. Alkyl thioether hydroximic acids are hydroximic acids containing a thioether structure. Introduction of thioether structures may improve the hydrophobicity of the molecule, possibly exhibiting certain specific physicochemical properties. However, their use as protein deacetylase inhibitors has been mainly reported so far, and for example, US20020143196a1 discloses the preparation of benzylthioether ethylhydroxamic acid and its use as histone deacetylase inhibitors for the treatment of cancer, hematological diseases and genetically related metabolic diseases. The application of the flotation collector in flotation is not reported.

Disclosure of Invention

the first purpose of the invention is to provide a method for utilizing a byproduct, namely sodium 2-mercaptoacetate in the production process of thiourethane. The method is characterized in that 2-sodium thioglycolate in a thiourethane synthesis process is used as a raw material to prepare alkyl thioether carboxylic acid, and the alkyl thioether carboxylic acid is subjected to hydroximization reaction to obtain novel alkyl thioether ethyl hydroximic acid. The method has the characteristics of simple operation, high utilization rate of raw materials, environmental friendliness and the like, can be directly coupled with the thiourethane synthesis process on the basis of not changing the conventional thiourethane production process, and is easy to realize industrial production. The method thoroughly solves the problem that the byproduct sodium 2-mercaptoacetate in the thiourethane synthesis process is difficult to recover.

the second invention aims to synthesize a brand-new alkyl thioether ether-based ethyl hydroximic acid compound with excellent extraction performance and collection performance by using the method.

In order to realize the technical purpose, the invention provides a utilization method of byproduct sodium 2-mercaptoacetate in a thiourethane synthesis process, which comprises the following specific steps:

Step 1): carrying out substitution reaction on an aqueous solution of 2-sodium thioglycolate and a halogenated reagent with a structure shown in a formula I to obtain sodium alkyl thioether acetate with a structure shown in a formula II;

Step 2): acidifying the sodium alkyl thioether acetate to obtain alkyl thioether acetic acid with a structure shown in a formula III;

Step 3): carrying out esterification reaction on alkyl thioether acetic acid and methanol to obtain alkyl thioether methyl acetate with a structure shown in a formula IV;

Step 4): and (3) reacting the alkyl thioether methyl acetate with hydroxylamine hydrochloride and sodium hydroxide to obtain the alkyl thioether ethyl hydroximic acid with the structure shown in the formula V.

The invention aims to solve the problem of the direction of the byproduct sodium 2-mercaptoacetate in the thiourethane synthesis process. In order to solve the technical problem, the invention firstly and innovatively provides a thought of converting the byproduct sodium 2-mercaptoacetate into alkyl thioether-based ethyl hydroximic acid; in the implementation of the innovative preparation idea, the inventor unexpectedly finds that the alkyl thioether ether ethyl hydroximic acid obtained by conversion has excellent oxide ore collecting performance and extraction performance.

The invention uses 2-sodium thioglycolate aqueous solution as raw material to react with halogenated reagent to obtain alkyl thioether-based carboxylic acid, thus solving the problem of the direction of 2-sodium thioglycolate, in particular to the byproduct sodium 2-thioglycolate in the thiourethane synthesis process; the alkyl thioether carboxylic acid is further hydroximized to synthesize the alkyl thioether hydroximic acid, and the alkyl thioether hydroximic acid is found to have unexpected collecting capacity and extraction capacity in the flotation of nonferrous metal oxidized ores.

The method comprises the steps of reacting a byproduct sodium 2-mercaptoacetate aqueous solution in a thiourethane synthesis process with a halogenated reagent to obtain sodium alkyl thioether acetate, acidifying, and then carrying out methanol esterification and hydroxylamine hydrochloride hydroximization reaction to obtain an alkyl thioether ethyl hydroximic acid product. The specific synthetic route comprises four steps:

Step 1) reacting 2-mercaptoethanol sodium with a halogenated reagent with a structure shown in a formula I to obtain the sodium alkyl thioether acetate with a structure shown in a formula II, wherein the reaction is shown in a reaction formula (1).

Preferably, R is¹Is C₁～C₁₆Alkyl or C₃～C₁₆Cycloalkyl groups of (a); x is halogen; the alkyl or cycloalkyl group optionally contains phenyl, substituted phenyl, C₁～C₈At least one substituent of the alkoxy group of (1).

The alkyl group is, for example, a straight chain or branched chain alkyl group. The cycloalkane is, for example, a ternary or higher monocyclic ring, a spiro ring or a bridged ring.

Further preferably, R¹Is ethyl, isopropyl, isobutyl, tert-butyl, benzyl, benzylethyl or cyclohexyl.

Preferably, X is Br or Cl.

In a more preferred embodiment, the reaction conditions in step 1) are: the reaction temperature is 30-120 ℃, and the reaction time is 2-10 h.

in a more preferable scheme, the addition amount of the halogenating agent is 0.9-1.5 times of the molar amount of the 2-sodium thioglycolate, and the addition amount of the sodium hydroxide is 0.5-3.5 times of the molar amount of the 2-sodium thioglycolate.

And 2) acidifying the sodium alkyl thioether acetate with the structure shown in the formula II to obtain the alkyl thioether acetic acid with the structure shown in the formula III as shown in a reaction formula (2).

in a more preferable embodiment, the acidification conditions in step 2) are as follows: the acid is at least one of hydrochloric acid, sulfuric acid or nitric acid, and is acidified until the pH of the mixture is 0.5-5.0.

step 3) carrying out esterification reaction on alkyl thioether-based acetic acid with a structure shown in a formula III and methanol to obtain alkyl thioether-based methyl acetate with a structure shown in a formula IV as shown in a reaction formula (3);

More preferably, the reaction conditions of step 3) are as follows: the reaction temperature is 50-100 ℃, the reaction time is 1-6 h, the molar ratio of the alkyl thioether-based acetic acid to the methanol is 1.0: 1.0-8, and concentrated sulfuric acid is used as a catalyst.

and 4) carrying out hydroximization reaction on the alkyl thioether methyl acetate with the structure shown in the formula IV, hydroxylamine hydrochloride and sodium hydroxide as shown in a reaction formula (4), and further acidifying the product to obtain alkyl thioether ethyl hydroximic acid with the structure shown in the formula V.

In a more preferred embodiment, the reaction conditions in step 4) are: the reaction temperature is 10-60 ℃, and the reaction time is 2.5-6 h.

In a more preferable embodiment, the molar ratio of the methyl alkyl sulfide acetate, the hydroxylamine hydrochloride and the sodium hydroxide is 1.0: 1.0-1.5, and the amount of the solvent water is 10-100 mL of distilled water/0.1 mol of alkyl sulfide acetic acid.

The invention also provides a utilization method of the byproduct sodium 2-mercaptoacetate in the production process of thiourethane, wherein the sodium 2-mercaptoacetate is obtained from the byproduct in the production process of thiourethane, and the sodium 2-mercaptoacetate obtained from the byproduct is converted into alkyl thioether ethyl hydroximic acid by utilizing the utilization method of the sodium 2-mercaptoacetate.

The method for obtaining the 2-sodium thioglycolate comprises the following steps: performing esterification reaction on xanthate with a structural formula VI, 2-chloroacetic acid and sodium carbonate, and then performing ammonolysis reaction on the xanthate with the structural formula VI and fatty amine with the structural formula VII to obtain thiourethane with the structural formula VIII, wherein a byproduct is obtained in the process of preparing thiourethane to obtain an aqueous solution of 2-sodium thioglycolate.

The invention utilizes the innovative idea of converting the 2-sodium thioglycolate into the alkyl thioether-based ethyl hydroximic acid to solve the problem of the direction of the byproduct sodium 2-thioglycolate in the production process of the thiourethane. The invention uses the byproduct sodium 2-thioglycolate aqueous solution in the production process of thiourethane as a raw material to react with a halogenated reagent to obtain the alkyl thioether-based carboxylic acid, thoroughly solves the problem of the byproduct sodium 2-thioglycolate in the thiourethane synthesis process, and changes waste into valuable. The synthesis method is simple to operate, has high atom utilization rate, can be directly coupled with the thiourethane synthesis process on the basis of not changing the existing thiourethane production process, meets the requirement of environmental protection, and is easy to realize industrialization; in addition, the alkyl thioether carboxylic acid is further hydroximized to synthesize the alkyl thioether hydroximic acid, and the alkyl thioether hydroximic acid is applied to the flotation of the nonferrous metal oxidized ore, and the idea is not reported at home and abroad.

The 2-sodium thioglycolate is derived from an aqueous solution of the 2-sodium thioglycolate obtained in the process of preparing the thionocarbamate by carrying out esterification reaction on xanthate, 2-chloroacetic acid and sodium carbonate and carrying out ammonolysis reaction on the xanthate and fatty amine, and the chemical reaction equations are shown as a reaction formula (5) and a reaction formula (6).

In a more preferred embodiment, the esterification conditions are as follows: the reaction temperature is 20-100 ℃, and the reaction time is 1-8 h.

In a more preferable embodiment, the molar ratio of the 2-chloroacetic acid to the xanthate to the sodium carbonate is 1.0: 1.0-1.2: 0.4 to 1.0.

In a preferred scheme, water is used as a solvent in the esterification reaction, and on one hand, the water is wide in source and cheap; on the other hand, the raw materials of alkyl xanthate, 2-chloroacetic acid and sodium carbonate can be dissolved in water, so that the reaction is a homogeneous reaction.

in a further preferable scheme, the using amount of the solvent water is 0-50 ml of water per 0.1mol of 2-chloroacetic acid.

In a more preferred embodiment, the ammonolysis reaction conditions are as follows: the reaction temperature is 20-90 ℃, the reaction time is 0.5-3 h, and the molar ratio of the xanthate to the fatty amine is 1.0: 1.0-1.5.

More preferred embodiment, R²Is C₁～C₁₆Alkyl of (C)₆～C₁₆Aryl or C of₃～C₁₆Or an alkoxyalkyl group of the structure of formula IX. R³is C₁～C₈Alkyl group of (1).

R⁴-O-R⁵-

Formula IX

In the formula IX, R⁴Is C₁～C₁₂Alkyl or C₆～C₁₂Aryl of (a); r⁵Is C₁～C₆An alkylene group of (a). The alkylene group is, for example, methylene, 1, 2-ethylene, 1, 3-propylene, 1, 4-butylene or 1, 5-pentylene.

The aryl group in the invention is, for example, a five-membered or more aromatic group, such as an aromatic heterocycle or a benzene ring, or a fused ring structure in which any two or more of the aromatic heterocycle and the benzene ring are fused.

Further preferred embodiment is the case where R²ethyl, isopropyl, isobutyl, tert-butyl, isopentyl, phenyl, benzyl, benzylethyl, p-tert-butylbenzyl, tert-butyloxyethyl, tert-butyloxymethyl, and the like; r⁴Selected from methyl, ethyl, n-propyl, n-butyl, n-pentyl, etc.

The invention creatively takes the water solution of the byproduct sodium 2-mercaptoacetate in the thiourethane process as the raw material to react with the halogenated reagent to synthesize the alkyl thioether carboxylic acid and the alkyl thioether ethylhydroxamic acid.

the invention develops a brand-new application of alkyl thioether-based ethyl hydroximic acid with a structure shown in a formula V in the field of mineral flotation, and researches find that the alkyl thioether-based ethyl hydroximic acid shows excellent flotation capability in the field of oxidized ore flotation.

the invention also provides an alkyl thioether-based ethyl hydroximic acid with the structure of the formula V, which is used as a metal ion extracting agent, wherein the metal ion is iron ion, copper ion, nickel ion, ferrous ion or rare earth metal ion.

Preferably, in the extraction process, the ratio of the organic phase to the water phase is 1-2: 1-2. The extraction temperature is preferably 25-35 ℃. The extraction time is preferably 5-60 min.

Preferably, the basic scheme of the alkyl thioether ethyl hydroximic acid medicament as an extractant of metal ions is as follows: (1) dissolving alkyl thioether ether radical ethyl hydroximic acid in kerosene to prepare an organic phase with the content of 1-20 percent; (2) adding an organic phase prepared from alkyl thioether ether ethyl hydroximic acid into a metal ion aqueous solution, wherein the ratio of the organic phase to the aqueous phase is 1: 1; (3) controlling the temperature of an oscillator to be 25-35 ℃, fully oscillating the mixture in the oscillator to fully dissolve metal ions into the added hydroximic acid, standing for separating liquid, and separating liquid after liquid is layered to extract the metal ions.

The alkyl thioether-based ethyl hydroximic acid extracting agent used in the invention has strong extraction capability on metal ions such as iron ions, copper ions, nickel ions, ferrous ions, rare earth metal ions and the like. The hydroximic acid is used as an extracting agent, an alkyl thioether ether ethyl hydroximic acid medicament is prepared into an organic phase with the content of 1-20% by using a solvent, and the organic phase is extracted for 5-60 min at the temperature of 25-35 ℃, so that more than 90% of metal ions can be extracted.

The invention also provides R of the formula X²an O-alkoxyalkyl-N-alkylthiocarbamate collector of a brand new structure that is an alkoxyalkyl structure (group of formula IX) and applied to the flotation of non-ferrous metal sulphide minerals;

R⁴Is C₁～C₁₂Alkyl or C₆～C₁₂aryl of (a); r⁵Is C₁～C₆An alkylene group of (a).

The technical key point of the invention is to utilize 2-sodium thioglycolate in the traditional thiourethane synthesis process, react the 2-sodium thioglycolate serving as a raw material with a halogenated reagent to synthesize alkyl thioether acetic acid, and then carry out esterification and hydroximization reactions on the alkyl thioether acetic acid to obtain the novel oxidized ore collecting agent alkyl thioether ethyl hydroximic acid. Meanwhile, the invention also prepares novel thiourethane with an alkoxy alkyl structure under the existing process conditions, and applies the novel thiourethane to the flotation collector. The method has the obvious advantages that: 1) the method thoroughly solves the problem that the recovery of the 2-sodium thioglycolate in the thiourethane synthesis process is difficult, and has simple operation and high atom utilization rate; 2) 2-sodium thioglycolate is converted into alkyl thioether-based carboxylic acid and alkyl thioether-based ethyl hydroximic acid with higher economic value, and the alkyl thioether-based carboxylic acid and the alkyl thioether-based ethyl hydroximic acid are applied to a flotation collector, so that the problem of the direction of the 2-sodium thioglycolate is solved; 3) a series of novel O-alkoxy alkyl-N-alkyl thiocarbamate is synthesized on the basis of the existing thiourethane production process, and the thiourethane has the advantages of small smell, high collecting capacity and the like, and meets the requirement of environmental protection; 4) the synthesis of the alkyl thioether ether ethyl hydroximic acid uses the sodium 2-mercaptoacetate generated by the prior thiourethane synthesis process as a raw material, so that the two processes can be coupled, and the method is easy to industrialize.

advantageous effects

(1) The technical scheme of the invention adopts a byproduct sodium 2-mercaptoacetate aqueous solution in a thiourethane synthesis process as a raw material to directly react with a halogenated reagent to obtain the alkyl thioether ethyl carboxylic acid, and then the alkyl thioether ethyl carboxylic acid is subjected to methanol esterification and hydroxylamine hydrochloride hydroximization reaction to prepare the alkyl thioether ethyl hydroximic acid. The technical scheme does not need to change the prior thiourethane synthesis process, and is easy to realize the co-production of thiourethane and alkyl thioether-based ethyl hydroximic acid.

(2) According to the invention, the 2-sodium thioglycolate is used for preparing the alkyl thioether-based ethyl hydroximic acid, and researches show that the thioether groups in the molecules can increase the hydrophobicity of the molecules, so that the hydroximic acid molecules and the hydroximic groups can be used for improving the flotation and collection capacity of the hydroximic acid molecules on oxidized ore in a synergistic manner, and in addition, the hydroximic acid has good extraction performance on iron ions, copper ions, nickel ions, ferrous ions or rare earth metal ions.

Drawings

FIG. 1 is an infrared spectrum of benzylthioether-based acetic acid;

FIG. 2 is an infrared spectrum of benzylthioether ethyl hydroximic acid;

FIG. 3 is a drawing of benzylthioether-based acetic acids¹H NMR chart;

FIG. 4 shows benzylthioether acetic acids¹³c NMR chart;

[ FIG. 5 ] A process for preparing benzylthioether ethyl hydroximic acid¹h NMR chart;

[ FIG. 6 ] A process for preparing benzylthioether ethyl hydroximic acid¹³C NMR chart.

Detailed Description

The invention is further illustrated by, but is not limited to, the following examples. All parts and percentages in the examples are by mass unless otherwise specified.