4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol compound and its preparation method and application

Abstract

The present invention discloses a 4,5,6,7-tetrahydro-1H-benzimidazole-1-ylmethanol compound and its preparation method and application. The compound of the present invention has a structure shown in Formula I or Formula II: wherein: R is selected from C 1‑6 Alkyl, C 3‑6 Cycloalkyl, 5-6 membered heterocyclic groups, such as furyl, thienyl, pyrrolyl, and pyridyl. The present invention structurally modifies the 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol core with an organic acid (such as furanoic acid) to obtain a (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methanol compound with excellent corrosion resistance. 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.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal corrosion protection, and specifically relates to a 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol compound, a preparation method and an application thereof. 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] To address the above technical issues, the present invention provides a 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol-based compound, its preparation method, and its application. The present invention structurally modifies the 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol core with a compound containing a carboxylic acid group, resulting in a 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol-based compound with excellent corrosion resistance. The compound of the present invention can prevent metal corrosion in alkaline environments without significantly decreasing the pH of the test solution.

[0006] In order to achieve the above object, the present invention provides a compound with a structure shown in Formula I:

[0007]

[0008] in:

[0009] R is selected from C 1-6 Alkyl, C 3-6 Cycloalkyl, 5-6 membered heterocyclic group, such as furyl, thienyl, pyrrolyl, pyridyl.

[0010] According to an embodiment of the present invention, the compound of the structure shown in Formula I is selected from the following compounds:

[0011]

[0012] The present invention also provides a method for preparing the compound of the structure shown in the above-mentioned formula I, its stereoisomers or pharmaceutically acceptable salts and hydrates thereof, comprising reacting (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol with the compound R-COOH to obtain the compound of the structure shown in formula I; wherein: R has the definition and selection as described above.

[0013] According to an embodiment of the present invention, the molar ratio of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol to the compound R-COOH is 1:(0.5-2), exemplified by 1:0.5, 1:1, and 1:2.

[0014] According to an embodiment of the present invention, in the reaction of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol with the compound R-COOH, a catalyst and a dehydrating agent are preferably added.

[0015] Preferably, the amount of the catalyst used is 10 to 30 mol% of the amount of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol used, exemplified by 10 mol%, 20 mol%, and 30 mol%.

[0016] Preferably, the catalyst is selected from at least one of 4-dimethylaminopyridine (DMAP), 1,1'-bisdiphenylphosphinoferrocene, palladium dichloride, palladium dichloride, palladium acetate, tetrakis(triphenylphosphine)palladium and tris(dibenzylideneacetone)dipalladium.

[0017] Preferably, the molar ratio of the 1-chloromethyl-4,5,6,7-tetrahydro-1H-benzimidazole to the dehydrating agent is 1:(1-5), exemplified by 1:1, 1:1.1, 1:1.5, 1:2, and 1:5.

[0018] In one embodiment of the present invention, the dehydrating agent is selected from 1,3-dicyclohexylcarbodiimide (DCC).

[0019] 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 1,2-dichloroethane and tetrahydrofuran.

[0020] In one embodiment of the present invention, the preparation method comprises dissolving (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol and compound R-COOH in an organic solvent, adding a dehydrating agent and a catalyst, and reacting to prepare a compound with the structure shown in Formula I.

[0021] In one embodiment of the present invention, the catalyst and the dehydrating agent are added at a temperature of -10 to 10°C, exemplified by -10°C, 0°C, and 10°C.

[0022] According to an embodiment of the present invention, the reaction temperature is, for example, 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.

[0023] 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 500): 1 (v / v), exemplified by 1:1, 100:1, and 500:1.

[0024] Preferably, the synthesis route of the compound represented by the structure of Formula I is as follows:

[0025]

[0026] 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:

[0027] (1) Dissolve (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol and R-COOH in an organic solvent, and then cool the reaction solution to -10 to 10°C;

[0028] (2) adding a dehydrating agent and a catalyst and stirring the reaction;

[0029] (3) After the stirring reaction is completed, the solvent is concentrated to remove;

[0030] (4) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate as eluent to obtain a compound with the structure shown in Formula I.

[0031] According to an embodiment of the present invention, the (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol is prepared by reacting 4,5,6,7-tetrahydro-1H-benzimidazole with formaldehyde.

[0032] In one embodiment of the present invention, the molar ratio of 4,5,6,7-tetrahydro-1H-benzimidazole to formaldehyde is 1:(0.5-2), exemplified by 1:0.5, 1:1, and 1:2.

[0033] In one embodiment of the present invention, the preparation method of (4,5,6,7-tetrahydrobenzo[d]imidazol-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.

[0034] 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.

[0035] In one embodiment of the present invention, the preparation method further comprises the step of separating the solid product from the reaction mixture after the reaction is completed, for example, by spin-drying the solvent to obtain the solid product.

[0036] In one embodiment of the present invention, the synthesis route of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol is as follows:

[0037]

[0038] 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.

[0039] The present invention also provides a detergent containing the compound with the structure shown in the above formula I.

[0040] The present invention also provides a preservative containing the compound with the structure shown in the above formula I.

[0041] 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.

[0042] In one embodiment of the present invention, the sustained release agent is selected from triethanolamine borate.

[0043] In one embodiment of the present invention, the surfactant is 2-amino-2-methyl-propanol.

[0044] According to an embodiment of the present invention, the preservative further contains tetramethylammonium hydroxide.

[0045] 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%.

[0046] 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.

[0047] Definitions and Explanations of Terms

[0048] Unless otherwise indicated, the definitions of groups and terms in this specification and claims, including definitions used as examples, exemplary definitions, preferred definitions, definitions in tables, and definitions of specific compounds in the Examples, may be arbitrarily combined and coupled with one another. The resulting group definitions and compound structures shall fall within the scope of the description of this specification.

[0049] Unless otherwise indicated, numerical ranges recited in this specification and claims are equivalent to reciting at least each specific integer value therein. For example, the numerical range "1-6" is equivalent to reciting each integer value in the numerical range "1-6", namely 1, 2, 3, 4, 5, and 6. It should be understood that when used herein to describe a substituent, "a plurality" refers to an integer ≥ 2, such as 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0050] The term "C 1-6 The term "alkyl" refers to a straight-chain or branched saturated hydrocarbon group having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, or an isomer thereof.

[0051] The term "C 3-6 "Cycloalkyl" is understood to mean a saturated monocyclic alkane having 3, 4, 5 or 6 carbon atoms. For example, cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0052] The term "heterocyclyl" is understood to mean a saturated or partially unsaturated monocyclic or bicyclic non-aromatic cyclic group having 3 to 20 ring atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, etc.) containing 1 to 5 heteroatoms independently selected from N, O, and S, preferably a "3-10 membered heterocyclyl". The term "3-10 membered heterocyclyl" means a saturated or partially unsaturated monocyclic or bicyclic hydrocarbon ring containing 1 to 5, preferably 1 to 3, heteroatoms independently selected from N, O, and S, such as 1, 2, or 3 heteroatoms independently selected from N, O, and S. The heterocyclyl group may be attached to the rest of the molecule via any of the carbon atoms or the nitrogen atom (if present). In particular, the heterocyclic group may include, but is not limited to, a 4-membered ring such as azetidinyl or oxetanyl; a 5-membered ring such as furanyl, tetrahydrofuranyl, dioxolyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, pyrrolinyl; or a 6-membered ring such as tetrahydropyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, tetrahydropyridinyl, 2H-pyranyl, piperazinyl, or trithianyl; or a 7-membered ring such as diazepanyl. Optionally, the heterocyclic group may be benzo-fused. The ring containing the nitrogen atom may be partially unsaturated, i.e., it may contain one or more double bonds, such as, but not limited to, 2,5-dihydro-1H-pyrrolyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl, or 4H-[1,4]thiazinyl, or it may be benzo-fused, such as, but not limited to, dihydroisoquinolinyl. The heterocyclic group may be a spiro ring.

[0053] Beneficial effects of the present invention:

[0054] The present invention discloses a 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol compound, its preparation method, and application. The present invention structurally modifies the 4,5,6,7-tetrahydro-1H-benzimidazol-1-ylmethanol core with an organic acid (such as furanic acid) to obtain a (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methanol compound with excellent corrosion resistance. The compound can prevent metal corrosion in alkaline environments without significantly decreasing the pH value of the test solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in Example 1 1 H NMR spectrum.

[0056] Figure 2 (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in Example 1 13 C NMR spectrum.

[0057] Figure 3 This is the HRMS spectrum of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in Example 1. DETAILED DESCRIPTION

[0058] 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.

[0059] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0060] Example 1

[0061] This embodiment provides a method for preparing (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate, and the reaction equation is:

[0062]

[0063] The preparation method of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate comprises the following steps:

[0064] (1) Dissolve (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol (5.0 mmol, 760.5 mg) and 2-furancarboxylic acid (5.0 mmol, 560.1 mg) in 20.0 mL of dichloromethane, and then cool the reaction mixture to 0°C.

[0065] (2) Add 1,3-dicyclohexylcarbodiimide DCC (5.5 mmol, 1.1 g) and 4-dimethylaminopyridine DMAP (1.0 mmol, 122.1 mg), and then slowly heat the mixture to room temperature for reaction;

[0066] (3) After stirring the reaction overnight, the components were concentrated on a rotary evaporator at 40°C without any post-treatment.

[0067] (4) 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 1:1 as the eluent to obtain a white solid (yield: 60%). This solid is (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate, with the structural formula:

[0068]

[0069] Among them, the preparation method of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol has the following reaction equation:

[0070]

[0071] The preparation method of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol comprises the following steps:

[0072] (1) 4,5,6,7-tetrahydro-1H-benzimidazole (1.2 g, 10.0 mmol) and tetrahydrofuran (30.0 mL) were added sequentially to a 150.0 mL reaction flask, followed by dropwise addition of formaldehyde solution (37% concentration, 0.8 g, 10.0 mmol), and the mixture was stirred at room temperature for 12 h.

[0073] (2) After stirring for 12 h, without any post-treatment, the components were concentrated on a rotary evaporator at 40° C. to obtain the product (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol, whose structural formula is:

[0074] The characterization results of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in this example are as follows:

[0075] 1 H NMR (400MHz, CDCl3) δ7.59(s,1H),7.56(dd,J=1.8,0.8Hz,1H),7.18(dd,J=3.6,0.9Hz ,1H),6.48(dd,J=3.5,1.7Hz,1H),5.92(s,2H),2.65–2.44(m,4H),1.87–1.67(m,4H)( Figure 1 ).

[0076] 13 C NMR (101MHz, CDCl3) δ157.4,147.3,143.4,137.5,136.7,125.7,119.5,112.2,66.0,24.1,23.1,22.7,20.1( Figure 2 ).

[0077] HRMS (ESI) m / z measured the C 13 H 14 Molecular weight of N2O3 [M+H] + is 247.1077, and its theoretical molecular weight is 247.1069 ( Figure 3 ).

[0078] Test Example 1

[0079] 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.

[0080] Table 1

[0081]

[0082] Test Example 2

[0083] 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.

[0084] Table 2

[0085]

[0086] Test Example 3

[0087] To a 20.0 mL Erlenmeyer flask, add 10.0 g of DEV base (a 2.38% aqueous solution of tetramethylammonium hydroxide), 0.15 g of additive 1 (triethanolamine borate sustained-release agent), 0.01 g of additive 2 (2-amino-2-methyl-propanol surfactant), and 0.2 g of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in Example 1 (completely dissolved). 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, aluminum sheets were cut into 1 cm x 1 cm squares and placed in the Erlenmeyer flask. After soaking for 1 hour, the sheets were removed with tweezers, rinsed several times on both sides with distilled water, wiped dry, and weighed. The sheets were then placed in the solution again and soaked for another 2 hours (total 3 hours). The corroded sheets were weighed and the pH of the solution was then measured at 25-27°C. The results are shown in Table 3 below.

[0088] Table 3

[0089]

[0090]

[0091] Test Example 4

[0092] In a 20.0 mL Erlenmeyer flask, 10.0 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 (completely dissolved) of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate prepared in Example 1 were added. A magnet was added and electromagnetic stirring was started 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. The sheet was then placed in the solution again and soaked for another 2 hours (total 3 hours). The weight after corrosion was weighed and the pH value of the solution was then measured at 18°C. The results are shown in Table 4 below.

[0093] Table 4

[0094]

[0095] Test Example 5

[0096] Take 10.0g of each of the reference solutions I, II, III, and IV in Table 5 and add them to four conical flasks. Then add 20.0mg of (4,5,6,7-tetrahydro-1H-benzimidazol-1-yl)methylfuran-2-carboxylate (completely dissolved) prepared in Example 1. After dissolution, measure the pH value of the solution at 25-27°C. Then cut the aluminum sheet into 1cm*1cm small squares and place them in the conical flask. After soaking for 1 hour, remove it with tweezers, rinse both sides with distilled water several times, wipe dry and weigh; measure the pH value of the solution at 25-27°C. Then put it into the solution again, soak for another 2 hours (total 3 hours), weigh the weight after corrosion, and then measure the pH value of the solution at 25-27°C. The measurement results are shown in Tables 6 and 7 below.

[0097] Table 5

[0098]

[0099]

[0100] Note: “-” in the table means no addition; DEV base is a 2.38% aqueous solution of tetramethylammonium hydroxide, additive 1 is a triethanolamine borate sustained-release agent, and additive 2 is a 2-amino-2-methyl-propanol surfactant.

[0101] Table 6

[0102]

[0103] Note: Conditions Ⅰ, ⅠⅠ, ⅠⅠⅠ and ⅠV in the table correspond to the above-mentioned reference solutions Ⅰ, ⅠⅠ, ⅠⅠⅠ and ⅠV respectively.

[0104] Reference solution IV. Table 7

[0105]

[0106] Note: Condition Ⅰ, Condition ⅠⅠ, Condition ⅠⅠⅠ, and Condition ⅣV in the table correspond to the above-mentioned reference solution Ⅰ, reference solution ⅠⅠ, reference solution ⅠⅠⅠ, and reference solution ⅣV respectively.

[0107] 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 compound having a structure shown in formula I: In formula I, R is selected from furyl.

2. The method for preparing the compound of formula (I) according to claim 1, characterized in that: The preparation method comprises reacting (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol with a compound R-COOH to obtain a compound of the structure shown in formula I; wherein: R has the definition and selection as described in claim 1.

3. The preparation method according to claim 2, wherein The molar ratio of the (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol to the compound R-COOH is 1:(0.5-2).

4. The preparation method according to claim 2, wherein A catalyst and a dehydrating agent are added to the reaction of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol and the compound R-COOH.

5. The preparation method according to claim 4, wherein The amount of the catalyst used is 10 to 30 mol% of the amount of (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol used; And / or, the catalyst is selected from at least one of 4-dimethylaminopyridine (DMAP), 1,1'-bisdiphenylphosphinoferrocene, palladium dichloride, palladium dichloride, palladium acetate, tetrakistriphenylphosphine palladium and tris(dibenzylideneacetone)dipalladium.

6. The preparation method according to claim 4, wherein The molar ratio of the 1-chloromethyl-4,5,6,7-tetrahydro-1H-benzimidazole to the dehydrating agent is 1:(1-5); And / or, the dehydrating agent is selected from 1,3-dicyclohexylcarbodiimide (DCC).

7. The preparation method according to any one of claims 2 to 6, characterized in that: 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 1,2-dichloroethane and tetrahydrofuran.

8. The preparation method according to claim 7, wherein The preparation method comprises dissolving (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol and compound R-COOH in an organic solvent, adding a dehydrating agent and a catalyst, and reacting to prepare a compound with a structure shown in formula I.

9. The preparation method according to claim 8, wherein The addition temperature of the catalyst and the dehydrating agent is -10 to 10°C.

10. The preparation method according to any one of claims 2 to 6, characterized in that: The reaction temperature is room temperature; the reaction time is 1 to 48 hours.

11. The preparation method according to any one of claims 2 to 6, characterized in that: The preparation method further comprises drying the solvent to obtain a solid product after the reaction is completed.

12. The preparation method according to claim 11, 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=(1-500):

1.

13. The preparation method according to any one of claims 2 to 6, characterized in that: The method for preparing the compound of the structure shown in Formula I comprises the following steps: (1) Dissolve (4,5,6,7-tetrahydrobenzo[d]imidazol-1-yl)methanol and R-COOH in an organic solvent, and then cool the reaction solution to -10 to 10°C; (2) adding a dehydrating agent and a catalyst and stirring the reaction; (3) After the stirring reaction is completed, the solvent is concentrated to remove; (4) The crude product was purified by silica gel column chromatography using a mixed solvent of petroleum ether and ethyl acetate as eluent to obtain a compound with the structure shown in Formula I.

14. Use of the compound of formula I according to claim 1 in cleaning and anti-corrosion of metal product surfaces.

15. A detergent, characterized in that It contains the compound with the structure shown in formula I according to claim 1.

16. A preservative, characterized in that It contains the compound with the structure shown in formula I according to claim 1.

17. The preservative according to claim 16, 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.

18. The preservative according to claim 17, wherein The preservative also contains tetramethylammonium hydroxide.

19. The preservative according to claim 18, 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.

20. An anti-corrosion coating, characterized in that: It contains the compound with the structure shown in formula I according to claim 1.

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