4-amino-5-iminomethylpyrimidine derivatives, processes for their preparation and use in polyurethane materials

Abstract

The application discloses a novel compound 4-amino-5-iminomethyl pyrimidine derivative, a preparation method thereof and application of the compound as an ultraviolet absorber in polyurethane materials, and a structure formula of the compound is as follows: The compound is prepared by reacting a certain amount of 4,6-dichloro-5-pyrimidine formaldehyde, 5-amino-2-methyl quinoline and a solvent under certain temperature conditions. After the reaction is completed, the crude product is extracted and filtered, and then washed to obtain the pure 4-amino-5-iminomethyl pyrimidine derivative. The 4-amino-5-iminomethyl pyrimidine derivative contains multiple amine quinoline skeletons, can effectively absorb 200-300 nm ultraviolet light, and the amine active groups in the molecular structure can exist in the polyurethane material in the form of chemical reaction. The 4-amino-5-iminomethyl pyrimidine derivative prepared by the application can be used as an ultraviolet absorber, and is expected to improve the light stability of the polyurethane material.

Description

Technical Field

[0001] This invention relates to a novel compound, a 4-amino-5-imine methylpyrimidine derivative, its preparation method, and its application in polyurethane materials. Background Technology

[0002] Polyurethane materials are widely used in industries such as toys, furniture, automobiles, and medical and health care. When exposed to ultraviolet light, polyurethane materials are prone to discoloration and degradation. Adding ultraviolet absorbers to polyurethane materials can effectively alleviate the impact of ultraviolet light on the performance of polyurethane materials. Some ultraviolet absorbers are added directly and exist in polyurethane materials in a mixed physical form (Plastics Technology, 2024, 52(8):126-131). These ultraviolet absorbers often have migration and dissolution properties during use. Other ultraviolet absorbers exist in polyurethane materials in a chemical reaction form through polyurethane chain extender components (CN121801297A). The synthesis of these ultraviolet absorbers often has disadvantages such as multiple synthesis steps and high raw material costs. Therefore, the development of high-performance ultraviolet absorbers is of great significance for inhibiting the photo-oxidative degradation of polyurethane products, enhancing color stability, and extending product life. Schiff base ultraviolet absorbers have great flexibility in synthesis, highly adjustable structure, and active groups in the molecule can participate in the synthesis reaction of polyurethane. These unique structural and performance advantages have prompted extensive, systematic, and in-depth theoretical and applied research on Schiff alkaline ultraviolet absorbers. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a 4-amino-5-imine methylpyrimidine derivative with a simple preparation method, mild reaction conditions, no need for catalysts or additives, concise operation steps, complex product structure, and active groups in the molecular structure that can participate in polyurethane reactions, as well as the preparation method and application of the derivative.

[0004] This invention discloses a novel 4-amino-5-imine methylpyrimidine derivative, the structural formula of which is as follows: .

[0005] This invention patent also discloses a method for preparing the above-mentioned novel compound 4-amino-5-imine methyl pyrimidine derivative, specifically including the following steps: Step 1) Reacting a certain amount of 4,6-dichloro-5-pyrimidinecarboxaldehyde, 5-amino-2-methylquinoline and solvent under certain temperature conditions;

[0006] Step 2) After the reaction is complete, the crude product is obtained by filtration and washing to obtain the pure 4-amino-5-imine methylpyrimidine derivative; wherein the structural formula of the 4-amino-5-imine methylpyrimidine derivative is as follows: .

[0007] The above-mentioned 4-amino-5-imine methylpyrimidine derivative was prepared in anhydrous ethanol to form 10 -5 The solution, at room temperature, exhibits good UV absorption properties when tested for UV absorption at a concentration of mol / L.

[0008] Preferably, the solvent is anhydrous ethanol or ethyl acetate.

[0009] Preferably, the reaction temperature is 20-40°C. o C.

[0010] Preferably, the molar ratio of 4,6-dichloro-5-pyrimidinecarboxaldehyde and 5-amino-2-methylquinoline is 1:2.0-3.0.

[0011] Preferably, when the amount of 4,6-dichloro-5-pyrimidinecarboxaldehyde is 1 mmol, the amount of solvent is 1-3 mL.

[0012] This invention patent also discloses the application of a novel compound, a 4-amino-5-imine methylpyrimidine derivative, as an ultraviolet absorber in polyurethane materials.

[0013] The above technical solution has the following beneficial effects: 1. The reaction does not require catalysts or additives, the conditions are mild, and the product has a complex structure containing multiple aminoquinoline skeletons; 2. The substrate has three reaction sites, resulting in one condensation reaction and one substitution reaction, with high chemical selectivity; 3. The synthesis reaction steps are simple and efficient, and the condensation reaction and substitution reaction can be completed in one step; 4. The product structure contains active groups, which can exist in polyurethane materials in the form of chemical reactions through polyurethane end-capping agent components; 5. The 4-amino-5-imine methylpyrimidine derivative synthesized in this invention has good ultraviolet absorption performance. Attached Figure Description

[0014] Figure 1 The target compound of the present invention 1 H NMR spectrum.

[0015] Figure 2 The target compound of the present invention 13 C10 NMR spectrum.

[0016] Figure 3 This is the ultraviolet-visible absorption spectrum of the target compound in an embodiment of the present invention. Detailed Implementation

[0017] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0018] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make the invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of the invention. However, those skilled in the art will recognize that the technical solutions of the invention may be practiced with one or more of these specific details omitted, or other methods, components, apparatus, steps, etc., may be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the invention.

[0019] The present invention will be further described in detail below with reference to the embodiments.

[0020] This invention patent discloses a 4-amino-5-imine methylpyrimidine derivative, the structural formula of which is as follows: The preparation method of this derivative is described below in the examples.

[0021] Example: Preparation method of N,N'-bis(5-(2-methylquinolinyl))-6-chloro-4-amino-5-iminemethylpyrimidine.

[0022] Step 1) Add 1.0 mmol of 4,6-dichloro-5-pyrimidinecarboxaldehyde, 2.0 mmol of 5-amino-2-methylquinoline, and 2.0 mL of anhydrous ethanol to the reaction tube, and incubate at 25°C. o React for 5 hours under C conditions;

[0023] Step 2) After the reaction is complete, the crude product is obtained by filtration and washed with anhydrous ethanol to obtain pure N,N'-bis(5-(2-methylquinolinyl))-6-chloro-4-amino-5-iminemethylpyrimidine, with the following structural formula:

[0024]

[0025] Yield: 62%; Orange-yellow solid; as Figures 1 to 2As shown, its 1H NMR spectrum (DMSO-d6, 400 MHz) is as follows: δ 11.12 (s, 1H), 10.43 (s, 1H), 9.12 (d, J = 8.8 Hz, 1H), 8.44 (s, 1H), 8.23 ​​(d, J = 8.8 Hz, 1H), 7.94–7.64 (m, 5H), 7.51 (d, J = 8.8 Hz, 1H), 7.37 (d, J = 8.4 Hz, 1H), 6.87 (d, J = 8.0 Hz, 1H), 2.87 (s, 3H), 2.71 (s, 3H). Carbon NMR spectrum (DMSO-d6, 101 MHz): δ 192.2, 164.8, 161.2, 160.8, 159.5, 157.3, 147.6, 135.7, 133.5, 123.0, 123.7, 123.1, 122.8, 120.1, 116.5, 109.6, 109.2, 24.7, 20.8. High-resolution mass spectrometry (ESI) calcd for C 25 H 20 ClN6 + [M+H] + 439.1438, found 439.1428.

[0026] The preparation method employs mild reaction conditions, produces a complex product structure containing multiple aminoquinoline skeletons, and achieves condensation and substitution reactions through a single-step transformation. The synthesis steps are simple, requiring no catalysts or additives, and exhibit high chemical selectivity. The product structure contains active groups, allowing it to exist chemically in polyurethane materials via polyurethane end-capping agents. The 4-amino-5-imine methylpyrimidine derivative synthesized in this invention possesses excellent ultraviolet absorption properties.

[0027] Experimental example: in 10 -5 The UV-Vis absorption spectrum of N,N'-bis(5-(2-methylquinolinyl))-6-chloro-4-amino-5-iminemethylpyrimidine was measured at room temperature at a concentration of mol / L; Figure 3 It is known that N,N'-bis(5-(2-methylquinolinyl))-6-chloro-4-amino-5-iminemethylpyrimidine has strong ultraviolet absorption at 200-300 nm.

[0028] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A 4-amino-5-imine methylpyrimidine derivative, characterized in that: Its structural formula is as follows: .

2. A method for preparing the 4-amino-5-imine methylpyrimidine derivative of claim 1, characterized in that, It includes the following steps: Step 1) A certain amount of 4,6-dichloro-5-pyrimidinecarboxaldehyde, 5-amino-2-methylquinoline and solvent are reacted under certain temperature conditions; Step 2) After the reaction is complete, the crude product is obtained by filtration and washing to obtain the pure 4-amino-5-imine methylpyrimidine derivative; wherein the structural formula of the 4-amino-5-imine methylpyrimidine derivative is as follows: .

3. The method for preparing the novel 4-amino-5-imine methylpyrimidine derivative according to claim 2, characterized in that: The solvent is anhydrous ethanol or ethyl acetate.

4. The method for preparing the novel 4-amino-5-imine methylpyrimidine derivative according to claim 2, characterized in that: The reaction temperature is 20-40°C. o C.

5. The method for preparing the novel 4-amino-5-imine methylpyrimidine derivative according to claim 2, characterized in that: The molar ratio of 4,6-dichloro-5-pyrimidinecarboxaldehyde and 5-amino-2-methylquinoline is 1:2.0-3.

0.

6. The method for preparing the novel 4-amino-5-imine methylpyrimidine derivative according to claim 2, characterized in that: When the amount of 4,6-dichloro-5-pyrimidinecarboxaldehyde used is 1 mmol, the amount of solvent used is 1-3 mL.

7. The application of the novel 4-amino-5-imine methylpyrimidine derivative of claim 1, characterized in that: It is used to prepare ultraviolet absorbers for polyurethane materials.

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