CN114539164A

CN114539164A - Mercaptopyrimidine derivative, and preparation method and application thereof

Info

Publication number: CN114539164A
Application number: CN202210251414.6A
Authority: CN
Inventors: 邵明鲁; 孙天宇; 左姜; 浮历沛
Original assignee: Changzhou University
Current assignee: Changzhou University
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2022-05-27

Abstract

The invention provides a mercaptopyrimidine derivative, a preparation method and application thereof, wherein the molecular structural formula of the mercaptopyrimidine derivative is shown in the specification

Wherein R is an alkyl group other than methyl or an aralkyl group. The mercapto pyrimidine derivative is solid, has good stability, easy storage and transportation, excellent corrosion inhibition performance, simple preparation method, low cost and convenient industrial application.

Description

Mercaptopyrimidine derivative, and preparation method and application thereof

Technical Field

The invention relates to the field of heterocyclic compounds and preparation thereof, in particular to a mercaptopyrimidine derivative, and a preparation method and application thereof.

Background

The metal corrosion problem is distributed in various fields, all places related to metal materials have corrosion problems of different degrees, 1/10 metal materials in the world can not be recycled due to corrosion, the economic loss caused by corrosion accounts for about 3% -4% of the national GNP, and the economic loss caused by corrosion in China is in the range of billions of yuan RMB every year. In addition, metal corrosion also causes environmental pollution and ecological damage, which endangers human health. The corrosion inhibitor can effectively inhibit the metal from being damaged in a corrosion medium, so that the research on the corrosion inhibitor has very important significance.

Corrosion inhibitors are substances which, at low concentrations, inhibit the destruction of metals in corrosive media. After the corrosion inhibitor is added, the corrosion speed of the metal can be greatly reduced or close to zero, and the original surface performance, structural performance, physical performance and chemical performance of the metal material can not be changed. Compared with other corrosion prevention technologies, the corrosion inhibitor has the advantages of convenient use, no need of changing the nature of metal materials and corrosion media, simple process, excellent effect and strong applicability, and the current corrosion inhibitor protection method becomes one of the most widely applied methods in the metal corrosion protection technology.

At present, heterocyclic compounds have been widely researched and applied as corrosion inhibitors, but relatively few researches are conducted on pyrimidine substances. Researches show that some pyrimidine derivatives, especially mercapto pyrimidine derivatives, not only contain pyrimidine rings, but also contain nitrogen atoms and sulfur atoms in molecules, and after appropriate chemical modification, the pyrimidine derivatives have good corrosion inhibition performance. Therefore, the thiopyrimidine derivatives are a very potential corrosion inhibitor, but the current market for the thiopyrimidine derivatives has few corrosion inhibitors.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a mercaptopyrimidine derivative, a preparation method and application thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a mercapto pyrimidine derivative used as corrosion inhibitor and having molecular structural formula

Wherein R is an alpha-alkyl group or an alpha-aromatic hydrocarbon group other than methyl.

As a further improvement of the technical scheme, in order to improve the corrosion inhibition effect and control certain preparation cost, R is ethyl, propyl, n-butyl, n-pentyl, n-hexyl or benzyl.

The mercapto pyrimidine derivative is a biquaternary ammonium salt corrosion inhibitor, has the characteristics of good stability and water solubility, and has excellent corrosion inhibition performance. The molecular structure of the mercapto pyrimidine derivative corrosion inhibitor has a large influence on the corrosion inhibition performance, and the corrosion inhibition efficiency of the mercapto pyrimidine derivative corrosion inhibitor is gradually increased along with the increase of the length of a carbon chain, mainly because the carbon chain can be paved on the surface of metal as a hydrophobic chain to prevent hydrogen ions in acid liquor from contacting with the surface of the metal, and the carbon chain is increased to further inhibit the contact of the hydrogen ions with the surface of the metal; in addition, the mercapto pyrimidine derivative corrosion inhibitor containing benzene ring structure has better corrosion inhibition effect, because benzene ring can adsorb the metal surface through pi bond, the adsorption energy of the corrosion inhibitor is enhanced, and the corrosion inhibition efficiency is improved.

The invention also discloses a preparation method of the mercaptopyrimidine derivative, which has the advantages of easily obtained raw materials, simple steps and mild reaction conditions, is easy to industrialize and comprises the following specific preparation steps:

step one, weighing a certain mass of 4, 6-diamino-2-mercaptopyrimidine, dissolving the 4, 6-diamino-2-mercaptopyrimidine in a strong alkali water solution, heating to 50-80 ℃, and uniformly stirring. The strong base can be selected from sodium hydroxide, potassium hydroxide, barium hydroxide, sodium acetate, potassium acetate, etc.

And step two, slowly adding alpha-halohydrocarbon into the reaction system obtained in the step one, and then reacting for 5-8 hours under the air isolation condition to obtain the mercaptopyrimidine derivative, wherein inert gases insensitive to reaction such as nitrogen atmosphere and argon atmosphere can be adopted when air is isolated, and the reaction temperature in the step is 50-80 ℃. Because the mercaptopyrimidine derivative is prepared in the alkaline aqueous solution and the mercaptopyrimidine derivative is dissolved in the alkaline aqueous solution, the reaction product obtained in the step two is neutralized by acid, and then is sequentially filtered, washed and dried to obtain the purer mercaptopyrimidine derivative, and the purer mercaptopyrimidine derivative is preferably neutralized by organic weak acid, such as acetic acid, formic acid, caprylic acid and the like.

As a further improvement of the technical proposal, in order to improve the reaction activity and reduce the generation of byproducts, the alpha-halogenated hydrocarbon is alpha-brominated hydrocarbon.

As a further improvement of the technical scheme, based on the cost consideration and the improvement of the reaction yield, the molar ratio of the 4, 6-diamino-2-mercaptopyrimidine to the alpha-halogenated hydrocarbon in the second step is 1 (1.1-1.5).

As a further improvement of the technical proposal, in order to dissolve the 4, 6-diamino-2-mercaptopyrimidine, OH in the strongly alkaline aqueous solution in the first step^-The concentration of (2) is 1 mol/L.

As a further improvement of the technical scheme, in order to dissolve the 4, 6-diamino-2-mercaptopyrimidine, the solid-liquid mass ratio of the 4, 6-diamino-2-mercaptopyrimidine to the strong alkali aqueous solution in the first step is 1 (8-10).

As a further improvement of the technical solution, the strong alkaline aqueous solution is a sodium hydroxide solution based on cost considerations and dissolving 4, 6-diamino-2-mercaptopyrimidine.

The corrosion inhibitor prepared by the invention can effectively slow down the metal corrosion rate, meets the use requirement under the strong corrosion environment, has small harm to the environment and human body, and also discloses the application of the mercaptopyrimidine derivative in inhibiting corrosion in injected water, petroleum pipelines or acidic media of oil fields.

The invention also discloses a corrosion inhibitor composition containing the mercaptopyrimidine derivative, wherein the mercaptopyrimidine derivative is used as an effective corrosion inhibition component, or is compounded with other corrosion inhibition compounds such as propargyl alcohol compounds, iodides, surfactants, formamide compounds and the like to form a compound corrosion inhibitor.

Compared with the prior art, the corrosion inhibitor has outstanding substantive characteristics and remarkable progress, and particularly, the corrosion inhibitor can effectively slow down the metal corrosion rate, meets the use requirement under a strong corrosion environment, and has small harm to the environment and human bodies. Secondly, the corrosion inhibitor is easy to dissolve in aqueous solution, good in stability and wide in application prospect. The preparation method is simple, the reaction condition is mild, the product is easy to store, and the industrialization is easy to realize.

Drawings

FIG. 1 is a surface topography of N80 steel after corrosion without adding a corrosion inhibitor.

FIG. 2 is a surface topography of N80 steel after corrosion with the corrosion inhibitor of example 4 added.

Detailed Description

The technical solution of the present invention is further described in detail by the following embodiments.

The corrosion inhibition performance evaluation method in each embodiment comprises the following steps:

according to SY/T5329-2012 'water injection quality index and analysis method for clastic rock oil reservoirs', a weight loss hanging piece method is adopted to evaluate the corrosion inhibition performance of the corrosion inhibitor on N80 steel at 25 ℃ and 1mol/L hydrochloric acid solution, and the weight loss hanging piece time is 36 hours.

The surface topography of the corroded N80 steel is obtained by shooting through an SU8020 cold field scanning electron microscope.

The relative molecular weight and purity of the mercaptopyrimidine derivative are determined by a gas chromatography-mass spectrometer (GC-MSTQ 8040) under the chromatographic conditions that a chromatographic column is DB-5(60m multiplied by 0.25mm i.d.); the carrier gas is helium, the pressure is constant, and the pressure in front of the column is 206 kPa; the temperature of a sample inlet is 250 ℃; column temperature: the initial temperature is 90 ℃, the temperature is kept for 5min, then the temperature is increased to 280 ℃ at the temperature rising rate of 5 ℃/min, and the temperature is kept for 5 min; the sample injection amount is 1 mu L, and the sample injection is not divided. Mass spectrum conditions: electron impact ion source (EI); the ion source temperature is 250 ℃; the interface temperature is 280 ℃; mass spectrum scanning range: m/z is 13-449. The solvent delay time was 10 min.

Example 1

2g of 4, 6-diamino-2-mercaptopyrimidine is dissolved in 16g of sodium hydroxide solution, the concentration of the sodium hydroxide solution is 1mol/L, the mixture is stirred uniformly, 1.5g of bromoethane is added, and the mixture reacts for 5 hours at the temperature of 60 ℃. After the reaction is finished, the reaction solution is neutralized by acetic acid, filtered, washed and dried to obtain 2.35g of the mercaptopyrimidine derivative corrosion inhibitor, the purity of the inhibitor is 94.15%, and the relative molecular weight of the inhibitor is 170.

Example 2

2g of 4, 6-diamino-2-mercaptopyrimidine is dissolved in 16g of sodium hydroxide solution, the concentration of the sodium hydroxide solution is 1mol/L, the mixture is stirred uniformly, 1.5g of bromobutane is added, and the mixture reacts for 5 hours at the temperature of 60 ℃. After the reaction, the reaction solution was neutralized with acetic acid, filtered, washed, and dried to obtain 2.41g of a mercaptopyrimidine derivative corrosion inhibitor having a purity of 93.68% and a relative molecular weight of 198.

Example 3

2g of 4, 6-diamino-2-mercaptopyrimidine is dissolved in 16g of sodium hydroxide solution, the concentration of the sodium hydroxide solution is 1mol/L, the mixture is stirred uniformly, 1.5g of bromohexane is added, and the mixture is reacted for 5 hours at the temperature of 60 ℃. After the reaction, the reaction solution was neutralized with acetic acid, filtered, washed and dried to obtain 2.55g of a mercaptopyrimidine derivative corrosion inhibitor having a purity of 93.79% and a relative molecular weight of 226.

Example 4

2g of 4, 6-diamino-2-mercaptopyrimidine is dissolved in 16g of sodium hydroxide solution, the concentration of the sodium hydroxide solution is 1mol/L, the mixture is stirred uniformly, 1.5g of benzyl bromide is added, and the mixture reacts for 5 hours at the temperature of 60 ℃. After the reaction is finished, the reaction solution is neutralized by acetic acid, filtered, washed and dried to obtain 2.96g of the mercaptopyrimidine derivative corrosion inhibitor, the purity of the inhibitor is 95.44%, and the relative molecular weight of the inhibitor is 232.

The corrosion inhibiting properties of the mercaptopyrimidine derivatives prepared in the examples are shown in Table 1:

the corrosion inhibition performance of the corrosion inhibitor of the invention on N80 steel is evaluated by a weight loss coupon method in 1mol/L hydrochloric acid solution at 25 ℃, and the experimental results are shown in Table 1.

Table 1:

the blank case is a blank control experiment without adding any corrosion inhibitor, and the comparative example is a corrosion experiment with the corrosion inhibitor being 4, 6-diamino-2-mercaptopyrimidine. From comparison of surface topography maps of N80 steel after corrosion in figures 1 and 2 and test data in Table 1, it can be seen that in an evaluation system, the corrosion inhibitor of the invention has a significant inhibition effect on corrosion of N80 steel, and the corrosion inhibition performance of the corrosion inhibitor is superior to that of 4, 6-diamino-2-mercaptopyrimidine.

Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the same; although the present invention has been described in detail with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A mercaptopyrimidine derivative having a molecular structural formula:

wherein R is an alkyl group other than methyl or an aralkyl group.

2. The mercaptopyrimidine derivative of claim 1, wherein R is ethyl, propyl, n-butyl, n-pentyl, n-hexyl, or benzyl.

3. A process for the preparation of a mercaptopyrimidine derivative according to claim 1 or 2, characterized by comprising the specific steps of:

step one, weighing a certain mass of 4, 6-diamino-2-mercaptopyrimidine, dissolving the 4, 6-diamino-2-mercaptopyrimidine in a strong alkali aqueous solution, heating to 50-80 ℃, and uniformly stirring;

and step two, slowly adding alpha-halohydrocarbon into the reaction system obtained in the step one, and then reacting for 5-8 hours under the condition of air isolation to obtain the mercaptopyrimidine derivative.

4. The method according to claim 3, wherein the α -halogenated hydrocarbon is an α -brominated hydrocarbon.

5. The method according to claim 3, wherein the molar ratio of the 4, 6-diamino-2-mercaptopyrimidine to the α -halohydrocarbon in the second step is 1 (1.1 to 1.5).

6. The method according to claim 3, wherein OH in the aqueous solution of a strong alkali is used in the first step^-The concentration of (2) is 1 mol/L.

7. The preparation method according to claim 6, wherein the solid-liquid mass ratio of the 4, 6-diamino-2-mercaptopyrimidine to the strong base aqueous solution in the first step is 1 (8-10).

8. The method according to any one of claims 3 to 7, wherein the aqueous alkali solution is a sodium hydroxide solution.

9. Use of a mercaptopyrimidine derivative according to claim 1 or 2 for inhibiting corrosion in oilfield injection water, petroleum pipelines, or acidic media.

10. A corrosion inhibitor composition comprising a mercaptopyrimidine derivative according to claim 1 or 2.