Preparation method and application of compounds based on benzimidazol-1-ylmethanol core

Abstract

The present invention discloses a preparation method and application of a compound based on a benzimidazole-1-ylmethanol core, wherein the compound comprises reacting (1H-benzimidazole-1-yl)methanol with a nucleophilic reagent R-XH to prepare the compound. The present invention uses cheap raw materials and simple synthesis steps, which not only achieves a significant reduction in cost, but also ensures a higher yield, thereby laying a solid foundation for the large-scale production of benzimidazole-1-ylmethanol core compounds. At the same time, the present invention ensures the quality and stability of the final product by accurately controlling the reaction conditions and optimizing the operating process. The compound of the present invention can prevent metal from being corroded in an alkaline environment and the pH value of the test solution does not decrease significantly. The present invention can select suitable chemical reagents and chemicals to modify and replace the compound based on "benzimidazole-1-ylmethanol" as the core according to different needs to meet different needs.

Description

Technical Field

[0001] The invention belongs to the technical field of metal corrosion protection, and particularly relates to a preparation method and application of a compound based on an imidazole-1-ylmethanol core. Background Art

[0002] Metal corrosion is a phenomenon in which metals are destroyed by chemical or electrochemical effects of the environment. Metal corrosion affects all areas of marginal industrial production, causing huge economic losses and leading to an increase in the use of metal materials, which is not conducive to energy conservation, emission reduction and environmental protection.

[0003] Metal corrosion mainly includes two forms: electrochemical corrosion and seawater corrosion. Electrochemical corrosion is the damage caused by the electrochemical reaction between the metal surface and the ion-conducting medium. Its main characteristic is that its reaction process can be divided into two relatively independent and simultaneous processes: the cathodic reaction and the anodic reaction. Its main feature is the existence of a charged interface layer between the metal and the electrolyte. Seawater corrosion refers to the corrosion of equipment and facilities used in the marine environment. Seawater has the highest salt content and a complex composition, making it a corrosive electrolyte. The high concentration of chloride ions and other halide ions in seawater can prevent and destroy the passivation of metals, making the anodic process easier to proceed. Under the pH conditions of seawater, seawater corrosion is an oxygen depolarization process, and the cathodic process controls the speed of the corrosion reaction.

[0004] For a long time, people have been using a variety of technologies to protect metals. One of the most effective and economical methods is to apply an anti-corrosion coating to the metal surface to isolate the corrosive medium from the metal substrate. However, during its use, the coating will produce microcracks due to changes in factors such as the environment or mechanical properties. Due to exposure to the atmosphere, the microcracks will gradually spread and expand, thereby accelerating the peeling and delamination of the coating at the metal-coating interface, reducing the service life and anti-corrosion ability of the coating, and also affecting the use of the metal. Therefore, there is a need for a metal preservative that can prevent the corrosion of metal materials and solve the problems of metal anti-corrosion coatings in the existing technology that are prone to cracking, flaking, and poor anti-corrosion effect. Summary of the Invention

[0005] In order to improve the above technical problems, the present invention provides a preparation method and application of a compound based on a benzimidazol-1-ylmethanol core. The compound of the present invention can prevent metal corrosion in an alkaline environment and the pH value of the test solution does not decrease significantly.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for preparing a compound of the structure shown in Formula I, a stereoisomer thereof, or a pharmaceutically acceptable salt or hydrate thereof, comprising reacting (1H-benzimidazol-1-yl)methanol with a compound R-XH to obtain a compound of the structure shown in Formula I;

[0008]

[0009] In formula I, R is selected from 2-mercaptobenzothiazolyl, N-hydroxysuccinimide, N-(tert-butyloxycarbonyl)-p-toluenesulfonamide or tetrahydro-2H-pyran-2-hydroxy; and X is selected from O, S or N.

[0010] According to an embodiment of the present invention, the molar ratio of (1H-benzimidazol-1-yl)methanol to compound R-XH is 1:(1-5), exemplified by 1:1, 1:2, and 1:5.

[0011] According to an embodiment of the present invention, in the reaction of (1H-benzimidazol-1-yl)methanol with compound R-XH, triphenylphosphine (PPh3) and diisopropyl azodicarboxylate (DIAD) are preferably added.

[0012] Preferably, the molar ratio of the 1-chloromethyl-1H-benzimidazole to triphenylphosphine (PPh3) is 1:(1-5), exemplified by 1:1, 1:3, and 1:5.

[0013] Preferably, the molar ratio of the 1-chloromethyl-1H-benzimidazole to diisopropyl azodicarboxylate (DIAD) is 1:(1-5), exemplified by 1:1, 1:3, and 1:5.

[0014] According to an embodiment of the present invention, the method for preparing the compound of the structure represented by Formula I can be carried out in the presence of a solvent such as an organic solvent. For example, the organic solvent can be selected from tetrahydrofuran.

[0015] According to an embodiment of the present invention, the preparation method comprises dissolving (1H-benzimidazol-1-yl)methanol, compound R-XH, and triphenylphosphine (PPh3) in a solvent, and then mixing with diisopropyl azodicarboxylate (DIAD). Preferably, the mixing temperature is -10 to 10°C, exemplified by -10°C, 0°C, 5°C, and 10°C.

[0016] According to an embodiment of the present invention, the reaction temperature is room temperature; the reaction temperature of 1 to 48 hours is exemplified by 1 hour, 4 hours, 8 hours, 12 hours, 24 hours, 36 hours, and 48 hours. In the present invention, room temperature refers to a temperature of 25°C.

[0017] According to an embodiment of the present invention, the preparation method further includes a step of isolating a solid product from the reaction mixture after the reaction is completed. For example, the solid product is obtained by spin-drying the solvent. Further, the preparation method also includes a step of purifying the product. For example, the purification can be performed by column chromatography. Preferably, the eluent for column chromatography separation is petroleum ether / ethyl acetate = (1 to 5): 1 (v / v), exemplified by 1:1, 3:1, and 5:1.

[0018] Preferably, the synthetic route of the compound of formula I is as follows:

[0019]

[0020] According to an embodiment of the present invention, the method for preparing the compound having the structure shown in Formula I comprises the following steps:

[0021] (1) Under nitrogen protection, (1H-benzimidazol-1-yl)methanol, nucleophile R-XH, and triphenylphosphine (PPh3) were dissolved in tetrahydrofuran, diisopropyl azodicarboxylate (DIAD) was added at low temperature, and then the temperature was raised and stirred for reaction;

[0022] (2) After the reaction is completed, the solvent is removed;

[0023] (3) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate as eluent to obtain the desired product.

[0024] According to an embodiment of the present invention, the (1H-benzimidazole-1-yl)methanol is prepared by reacting benzimidazole with formaldehyde.

[0025] In one embodiment of the present invention, the molar ratio of benzimidazole to formaldehyde is 1:(0.5-2), exemplified by 1:0.5, 1:1, and 1:2.

[0026] In one embodiment of the present invention, the preparation method of (1H-benzimidazol-1-yl)methanol can be carried out in the presence of a solvent such as an organic solvent. For example, the organic solvent can be selected from tetrahydrofuran.

[0027] In one embodiment of the present invention, the reaction temperature is room temperature; the reaction time is 1 to 48 hours, exemplified by 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, 12 hours, 16 hours, 24 hours, 36 hours, and 48 hours.

[0028] In one embodiment of the present invention, the preparation method further comprises a step of isolating a solid product from the reaction mixture after the reaction is completed. For example, the solid product is obtained by spin-drying the solvent. Furthermore, the preparation method further comprises a step of purifying the product. For example, the purification can be performed by recrystallization. Preferably, the solvent for the recrystallization can be ethanol and water.

[0029] In one embodiment of the present invention, the synthesis route of (1H-benzimidazol-1-yl)methanol is as follows:

[0030]

[0031] The present invention also provides a compound of the structure shown in Formula I prepared by the above preparation method, which is selected from the following compounds:

[0032]

[0033]

[0034] The present invention also provides the use of the compound represented by the structure of formula I in cleaning and anti-corrosion of metal product surfaces.

[0035] The present invention also provides a detergent containing the compound with the structure shown in the above formula I.

[0036] The present invention also provides a preservative containing the compound with the structure shown in the above formula I.

[0037] According to an embodiment of the present invention, the preservative further comprises an auxiliary agent. Preferably, the auxiliary agent is selected from a sustained-release agent and / or a surfactant.

[0038] In one embodiment of the present invention, the sustained release agent is selected from triethanolamine borate.

[0039] In one embodiment of the present invention, the surfactant is 2-amino-2-methyl-propanol.

[0040] According to an embodiment of the present invention, the preservative further contains tetramethylammonium hydroxide.

[0041] According to an embodiment of the present invention, in the preservative, the mass of the compound of the structure shown in Formula I is 0.01 to 20% of the mass of tetramethylammonium hydroxide, and exemplified by 0.01%, 0.04%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, and 20%.

[0042] The present invention also provides an anti-corrosion coating, which contains the compound with the structure shown in the above formula I and / or is prepared from the compound with the structure shown in the above formula I.

[0043] Beneficial effects of the present invention:

[0044] The present invention discloses a compound based on a benzimidazole-1-ylmethanol core, a preparation method thereof, and an application thereof. The preparation method of the present invention has the advantages of being economical, efficient, and easy to operate, and provides a solid foundation for the large-scale production and industrial application of compounds based on a benzimidazole-1-ylmethanol core. By selecting low-cost raw materials and simple synthesis steps, the present invention not only achieves a significant reduction in cost, but also ensures a high yield, thereby laying a solid foundation for further large-scale production of compounds based on a benzimidazole-1-ylmethanol core. At the same time, the method of the present invention ensures the quality and stability of the final product by precisely controlling the reaction conditions and optimizing the operating process. The compound of the present invention can prevent metal corrosion in an alkaline environment and the pH value of the test solution does not decrease significantly. The present invention can select suitable chemical reagents and chemicals to modify and replace the structure of the compound based on "benzimidazole-1-ylmethanol" as the core according to different needs to meet different needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole compound prepared in Example 1 1 H NMR spectrum.

[0046] Figure 2 The 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole compound prepared in Example 1 13 C NMR spectrum.

[0047] Figure 3 This is the HRMS spectrum of the 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole compound prepared in Example 1.

[0048] Figure 4 The tert-butyl ((1H-benzimidazol-1-yl)methyl)(toluenesulfonyl)carbamate compound prepared in Example 2 1 H NMR spectrum.

[0049] Figure 5 The tert-butyl ((1H-benzimidazol-1-yl)methyl)(toluenesulfonyl)carbamate compound prepared in Example 2 13 C NMR spectrum.

[0050] Figure 6 This is the HRMS spectrum of the tert-butyl ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamate compound prepared in Example 2. DETAILED DESCRIPTION

[0051] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0052] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0053] In the following embodiments of the present invention, the preparation method of (1H-benzimidazol-1-yl)methanol is as follows:

[0054]

[0055] The preparation method of (1H-benzimidazol-1-yl)methanol comprises the following steps:

[0056] (1) Benzimidazole (10.0 g, 84.65 mmol) and tetrahydrofuran (250.0 mL) were added sequentially to a 250.0 mL reaction flask, followed by dropwise addition of formaldehyde solution (37% in H2O, 6.8 g, 84.65 mmol). The mixture was stirred at room temperature for 12 h.

[0057] (2) After stirring for 12 h, the components were concentrated on a rotary evaporator without any post-treatment;

[0058] (3) The crude product was recrystallized from ethanol and water and filtered to obtain a white solid (yield 64%), namely (1H-benzimidazol-1-yl)methanol, with the structural formula:

[0059] Example 1

[0060] This embodiment provides a method for preparing 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole, and the reaction equation is:

[0061]

[0062] A method for preparing 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole comprises the following steps:

[0063] (1) Under nitrogen protection, (1H-benzimidazol-1-yl)methanol (1.48 g, 10.0 mmol), 2-mercaptobenzothiazole (1.67 g, 10.0 mmol), triphenylphosphine (7.87 g, 30.0 mmol, PPh3), and tetrahydrofuran (40.0 mL) were added to a 250.0 mL reaction flask in sequence. The reaction mixture was then cooled to 0°C and DIAD (6.07 g, 30.0 mmol, diisopropyl azodicarboxylate) was added dropwise. The temperature was then slowly raised to room temperature (25°C) and the reaction was continued for 36 h.

[0064] (2) After the reaction is completed, the components are concentrated on a rotary evaporator at 40°C without any post-treatment;

[0065] (3) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 3:1 as the eluent to obtain a white solid (yield: 67%), namely 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole, with the structural formula:

[0066] When DMF was used as solvent instead of THF, no 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole product was produced.

[0067] The basic parameters of the 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole compound prepared in this example are as follows:

[0068] 1 H NMR (400MHz, CDCl3) δ8.29(s,1H),7.98(d,J=8.1Hz,1H),7.79(m,1H),7.73(d,J=9.2Hz,1H),7.54–7.43(m,2H),7.37–7.28(m,3H),6.10(s,2H);

[0069] 13 C NMR (101MHz, CDCl3) δ163.1,152.6,144.1,143.1,135.6,133.0,126.5,125.0,123.5,122.9,122.0,121.3,120.8,110.0,45.8;

[0070] HRMS (ESI) m / z measured the C 15 H 11 Molecular weight of N3S2 [M+H] + The molecular weight is 298.0467, and its theoretical molecular weight is 298.0463.

[0071] Example 2

[0072] This embodiment provides a method for preparing tert-butyl ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamate, and the reaction equation is:

[0073]

[0074] The preparation method of tert-butyl ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamate comprises the following steps:

[0075] (1) Under nitrogen protection, (1H-benzimidazol-1-yl)methanol (1.48 g, 10.0 mmol), N-(tert-butyloxycarbonyl)-p-toluenesulfonamide (2.71 g, 10.0 mmol), triphenylphosphine (7.87 g, 30.0 mmol), and tetrahydrofuran (40.0 mL) were added to a 250.0 mL reaction flask in sequence. The reaction mixture was then cooled to 0°C and DIAD (6.07 g, 30.0 mmol, diisopropyl azodicarboxylate) was added dropwise. The temperature was then slowly raised to room temperature (25°C) and the reaction was continued for 36 h.

[0076] (2) After the reaction is completed, the components are concentrated on a rotary evaporator without any post-treatment;

[0077] (3) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 1:3 as the eluent to obtain a white solid (yield: 78%), namely, tert-butyl ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamate, with the structural formula:

[0078] The basic parameters of the tert-butyl ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamate compound prepared in this example are as follows:

[0079] 1 H NMR (400MHz, CDCl3) δ8.25 (s, 1H), 7.83–7.72 (m, 2H), 7.31–7.21 (m, 5H), 7.04 (d, J = 10.2Hz, 2H), 6.19 (s, 2H), 2.28 (s, 3H), 1.29 (s, 9H);

[0080] 13 C NMR (101MHz, CDCl3) δ150.5,144.7,144.4,143.2,136.0,133.0,129.2,127.4,123.5,122.6,120.1,110.9,86.1,53.1,27.6,21.4;

[0081] HRMS (ESI) m / z measured the C 20 H 23 Molecular weight of N3O4S [M+H] + The molecular weight is 402.14820, and its theoretical molecular weight is 402.14763.

[0082] Test Example 1

[0083] Add 10.0g of DEV base (a 2.38% aqueous solution of tetramethylammonium hydroxide) to a 20.0mL Erlenmeyer flask. Add a magnet and start electromagnetic stirring to mix the solution evenly. Set the water bath temperature to 25-27°C. Then cut the aluminum sheet into 1cm*1cm small squares and place them in the Erlenmeyer flask. After soaking for 1 hour, remove the sheet with tweezers, rinse both sides with distilled water several times, wipe dry, and weigh. Then, place the sheet back in the solution and soak for another 2 hours (a total of 3 hours). After that, weigh the corroded weight and measure the pH of the solution at 18°C. The results are shown in Table 1 below.

[0084] Table 1

[0085]

[0086] Test Example 2

[0087] To a 20.0 mL Erlenmeyer flask, add 10.0 g of DEV base (a 2.38% aqueous solution of tetramethylammonium hydroxide), 0.2 g of additive 1 (triethanolamine borate sustained-release agent), and 0.01 g of additive 2 (2-amino-2-methyl-propanol surfactant). Add a magnetic stirrer and stir until the solution is evenly mixed. Set the water bath temperature to 25-27°C. Then, cut the aluminum sheet into 1 cm x 1 cm squares and place them in the Erlenmeyer flask. After soaking for 1 hour, remove the sheet with tweezers, rinse both sides several times with distilled water, wipe dry, and weigh. Then, place the sheet back in the solution and soak for another 2 hours (for a total of 3 hours). After that, weigh the corroded sheet. The pH of the solution was then measured at 18°C. The results are shown in Table 2 below.

[0088] Table 2

[0089]

[0090] Test Example 3

[0091] In a 20.0 mL Erlenmeyer flask, 25.0 g of DEV base (aqueous solution of tetramethylammonium hydroxide at a concentration of 2.38%), 0.2 g of additive 1 (triethanolamine borate sustained-release agent), 0.01 g of additive 2 (2-amino-2-methyl-propanol surfactant), and 0.15 g of 2-(((1H-benzo[d]imidazol-1-yl)methyl)thio)benzo[d]thiazole prepared in Example 1 (insoluble, dispersed in the system) were added. A magnet was added and electromagnetic stirring was turned on to mix the solution evenly. The water bath temperature was set to 25-27°C. Subsequently, the aluminum sheet was cut into 1 cm*1 cm small squares and placed in the Erlenmeyer flask. After soaking for 1 hour, it was removed with tweezers, rinsed several times on both sides with distilled water, wiped dry, and weighed. Then, it was placed in the solution again and soaked for another 2 hours (a total of 3 hours). The weight after corrosion was weighed and the pH value of the solution was then measured at 18°C. The measurement results are shown in Table 3 below.

[0092] Table 3

[0093]

[0094] Test Example 4

[0095] To a 20.0 mL Erlenmeyer flask, add 25.0 g of DEV base (a 2.38% aqueous solution of tetramethylammonium hydroxide), 0.2 g of additive 1 (triethanolamine borate sustained-release agent), 0.01 g of additive 2 (2-amino-2-methyl-propanol surfactant), and 0.03 g of the ((1H-benzimidazol-1-yl)methyl)(tosyl)carbamic acid tert-butyl ester complexing agent prepared in Example 2 (insoluble, dispersed in the system). A magnet was added, and electromagnetic stirring was activated to mix the solution evenly. The water bath temperature was set to 25-27°C. Subsequently, the aluminum sheet was cut into 1 cm*1 cm squares and placed in the Erlenmeyer flask. After soaking for 1 hour, the sheet was removed with tweezers, rinsed several times on both sides with distilled water, wiped dry, and weighed. The sheet was then placed back into the solution and soaked for another 2 hours (a total of 3 hours). The corroded sheet was then weighed and the pH of the solution was measured at 18°C. The results are shown in Table 4 below.

[0096] Table 4

[0097]

[0098] The above describes the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing a compound having a structure shown in formula I, characterized in that: The method comprises reacting (1H-benzimidazol-1-yl)methanol with N-(tert-butyloxycarbonyl)-p-toluenesulfonamide to obtain a compound having a structure shown in Formula I; 2. The preparation method according to claim 1, wherein The molar ratio of (1H-benzimidazol-1-yl)methanol to N-(tert-butyloxycarbonyl)-p-toluenesulfonamide is 1:(1-5).

3. The preparation method according to claim 1, wherein In the reaction of (1H-benzimidazol-1-yl)methanol and N-(tert-butyloxycarbonyl)-p-toluenesulfonamide, triphenylphosphine (PPh3) and diisopropyl azodicarboxylate (DIAD) are added.

4. The preparation method according to any one of claims 1 to 3, wherein The preparation method of the compound represented by the structure of Formula I is carried out in the presence of an organic solvent, and the organic solvent is selected from tetrahydrofuran.

5. The preparation method according to any one of claims 1 to 3, wherein The preparation method further comprises drying the solvent to obtain a solid product after the reaction is completed.

6. The preparation method according to claim 5, wherein The preparation method further comprises the step of purifying the product, wherein the purification is carried out by column chromatography separation; the volume ratio of the eluent for the column chromatography separation is petroleum ether / ethyl acetate=(1-5):

1.

7. The preparation method according to any one of claims 1 to 3, characterized in that The method for preparing the compound of the structure shown in Formula I comprises the following steps: (1) Under nitrogen protection, (1H-benzimidazol-1-yl)methanol, N-(tert-butyloxycarbonyl)-p-toluenesulfonamide, and triphenylphosphine (PPh3) were dissolved in tetrahydrofuran, cooled to 0°C, and diisopropyl azodicarboxylate (DIAD) was added. The temperature was then raised and stirred for reaction. (2) After the reaction is completed, the solvent is removed; (3) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate as eluent to obtain the desired product.

8. The compound of formula I obtained by the preparation method according to any one of claims 1 to 7.

9. Use of the compound of formula I prepared by the preparation method according to any one of claims 1 to 7 in cleaning and anti-corrosion of metal product surfaces.

10. A detergent, characterized in that The invention comprises a compound having a structure shown in formula I prepared by the preparation method according to any one of claims 1 to 7.

11. A preservative, characterized in that The invention comprises a compound having a structure shown in formula I prepared by the preparation method according to any one of claims 1 to 7.

12. The preservative according to claim 11, wherein The preservative further comprises an adjuvant, wherein the adjuvant is selected from a sustained-release agent and / or a surfactant; The sustained-release agent is selected from triethanolamine borate; The surfactant is 2-amino-2-methyl-propanol.

13. The preservative according to claim 12, wherein The preservative also contains tetramethylammonium hydroxide.

14. The preservative according to claim 13, wherein In the preservative, the mass of the compound with the structure shown in Formula I is 0.01 to 20% of the mass of tetramethylammonium hydroxide.

15. An anti-corrosion coating, characterized in that: The invention comprises a compound having a structure shown in formula I prepared by the preparation method according to any one of claims 1 to 7.

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