1-pyrenecarboxaldehyde 4-(1, 2, 4-triazole-1-yl methyl) aniline Schiff base compound as well as preparation method and application thereof

Abstract

The invention discloses a Schiff base compound generated by condensation of 1-pyrenecarboxaldehyde and 4-(1, 2, 4-triazole-1-yl methyl) aniline as well as a preparation method and application of the Schiff base compound. The Schiff base compound has certain fluorescence and anti-DPPH free radical activity, and has potential application value in preparation of fluorescent materials and antioxidants.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical industry and pharmaceutical chemistry, in particular to a Schiff base compound generated by condensation reaction of 1-pyrromethane formaldehyde and 4-(1,2,4-triazole-1-ylmethyl) aniline, a preparation method thereof and an application thereof in the field of chemical industry and pharmaceuticals. BACKGROUND

[0002] Schiff base is a kind of organic compound containing-RC=N-structure, which is generally synthesized by condensation reaction of amine and aldehyde or ketone containing carbonyl group. It has very important application in various fields, especially in the fields of pharmaceuticals and chemical industry. Since the first Schiff base was synthesized in 1963, the synthesis and biological activity research of Schiff base and its derivatives have shown a rapid growth trend. By changing the structure of aldehyde or ketone, different Schiff base compounds can be synthesized in multiple ways, which have wide application in the fields of medicine, dyes, conductivity reagents and antioxidant activity.

[0003] DPPH (1,1-diphenyl-2-trinitrophenylhydrazine) method is widely used for quantitative analysis of free radical scavenging capacity, which has the advantages of good stability, high sensitivity and simple operation. Free radicals are the products of human metabolism, which show strong oxidative reaction capacity in the body. Excessive free radicals can cause oxidative damage to proteins, nucleic acids, lipids and other substances in the body, thereby causing various diseases such as atherosclerosis, neurodegeneration, chronic depression, cancer and physiological aging. Antioxidants have the effect of scavenging free radicals, and finding high-efficiency, non-toxic and safe antioxidants is an important research direction in the field of free radical biology.

[0004] In the prior art, Chinese patent CN108147997 A discloses a pyrazole aldehyde condensation aniline Schiff base compound, a preparation method and an application thereof, and the structural general formula is Chinese patent CN111087341 A discloses a carbazole-based Schiff base fluorescent material, and the structural general formula is Chinese patent CN202110720254.0 discloses a 1-pyrromethane formaldehyde condensation 3-amino-9-ethyl carbazole Schiff base compound and its antioxidant performance, and the structural formula is Chinese patent CN202111114981.9 discloses a plurality of 1-pyrromethane formaldehyde condensation morpholine aniline Schiff base compounds and their antioxidant activity, and the structural general formula is wherein R is selected from H, F

[0005] wherein R1 is selected from or As our research work in-depth, the present application provides a Schiff base condensed from 1-pyrene carboxaldehyde and 4-(1,2,4-triazole-1-ylmethyl) aniline, and its fluorescence properties and anti-DPPH free radical activity are explored. SUMMARY

[0006] The present application provides a Schiff base compound with structural formula III, and its structure is as follows:

[0007]

[0008] The preparation method of the Schiff base compound with general formula III comprises the following steps:

[0009] (1) dissolving the 4-(1,2,4-triazole-1-ylmethyl) aniline compound of formula II with a solvent;

[0010] (2) adding the 1-pyrene carboxaldehyde of formula I and the 4-(1,2,4-triazole-1-ylmethyl) aniline compound of formula II solution into a reaction device, heating to reflux, and reacting for 5 h;

[0011] (3) cooling, filtering, washing, and recrystallizing to obtain the target compound.

[0012] Preferably, the solvent in the step (1) is selected from the group consisting of anhydrous ethanol.

[0013] Preferably, the molar ratio of the raw material I to the raw material II in the step (2) is 1.0~1.5:1.

[0014] Preferably, the step (2) further comprises monitoring the reaction progress by TLC.

[0015] Preferably, the step (3) uses ethanol for washing and recrystallization.

[0016] In the specific embodiment of the present application, the reflux time is 5 h.

[0017] The present application provides a free radical scavenger, which comprises the Schiff base compound with structural formula III.

[0018] The present application provides a novel 1-pyrene carboxaldehyde condensed 4-(1,2,4-triazole-1-ylmethyl) aniline Schiff base, its preparation method and application. The preparation method of the Schiff base compound is simple, easy to purify, and easy to industrialize. The performance test shows that the Schiff base compound provided by the present application has certain free radical scavenging activity, and has potential application value in free radical scavengers and anti-aging drugs. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1Compound III 1 H NMR spectrum.

[0020] Figure 2 Compound III 13 C NMR spectrum.

[0021] Figure 3 HRMS spectrum of Compound III.

[0022] Figure 4 Radical scavenging rate curve of Compound III.

[0023] Figure 5 Fluorescence spectrum of Compound III. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0025] Example 1 Preparation of Compound III

[0026]

[0027] In a 100 mL three-necked flask, 0.23 g (1 mmol) of 1-pyrene carboxaldehyde and 0.174 g (1 mmol) of 4-(1,2,4-triazol-1-ylmethyl) aniline dissolved in 30 mL of anhydrous ethanol were added, heated and refluxed, the reaction was monitored by TLC, and the reaction was completed after 5 h. The solid was precipitated after cooling; the solid was washed with anhydrous ethanol for several times, recrystallized, filtered and dried to obtain 0.25 g of bright yellow solid, which was the target compound III. Yield: 65%; melting point: 184.6-185.9°C.

[0028] 1 H NMR (400Hz, DMSO, δ / ppm): 9.26 (s, 1H, CH=N), 8.12-8.23 (m, 11H, H on pyrrole and pyrene), 7.39-7.48 (m, 4H, H on benzene), 5.47 (s, 2H, CH2); the test spectrum is shown in Figure 1. Figure 1 .

[0029] 13C NMR (100 Hz, DMSO, δ / ppm): 159.90, 152.23, 152.11, 144.66, 134.50, 133.43, 131.24, 130.58, 130.55, 129.41, 128.70, 127.87, 127.20, 127.08, 126.79, 126.53, 125.52, 124.51, 124.15, 123.44, 122.06, 52.30. Test spectrum see attached Figure 2 .

[0030] Mass spectral data: HRMS (ESI) C 26 H 18 N4[M+H] + , the theoretical value: 387.1605; the test value: 387.1604. Test spectrum see attached Figure 3 .

[0031] Example 2 Determination of antioxidant activity of 1-pyrene formaldehyde condensed 4- (1, 2, 4-triazole-1-ylmethyl) aniline Schiff base compound

[0032] The antioxidant activity was determined by DPPH method.

[0033] DPPH method: DPPH is a very stable free radical centered on nitrogen, and its ethanol solution has a maximum absorption peak at 517 nm. If the Schiff base can scavenge it, it indicates that the Schiff base has the effect of reducing hydroxyl free radicals and breaking the lipid peroxidation chain reaction. At present, DPPH method has been widely used in the screening of free radical scavengers.

[0034] Experimental method: 0.2 mL of different concentrations of sample solution were mixed uniformly with 3.8 mL of DPPH ethanol solution with a concentration of 6.35 x 10 -6 mol / L, and placed in the dark for 30 min. With anhydrous ethanol as reference, the absorbance at 517 nm was measured, and the scavenging rate K of DPPH was calculated.

[0035] K = [(A0- As) / A0] * 100%,

[0036] A0is the absorbance of DPPH ethanol solution at 517 nm, and As is the absorbance at 517 nm after different concentrations of sample and DPPH solution react for 30 min. The scavenging rate of Schiff base on DPPH free radical was plotted against the concentration of solution, and the results are shown in the attached Figure 4 . From the attached Figure 4It can be known that the Schiff base has a certain degree of scavenging effect on hydroxyl radicals at different concentrations, the scavenging rate is between 6.8% and 13.4%, shows a certain antioxidant activity, and the activity is obviously affected by the concentration, the scavenging rate is the largest when the concentration is 0.10 g / L, and the scavenging rate is 13.4%. The Schiff base has potential application value in the field of antioxidants.

[0037] Example 3 Fluorescence performance test of 1-pyrene formaldehyde condensed 4-(1,2,4-triazole-1-ylmethyl) aniline Schiff base compound

[0038] At 10 -5 mol / L concentration, the fluorescence spectrum of the compound III is tested at room temperature; there is an attached Figure 5 It can be known that the compound has a very strong fluorescence spectrum at 438 nm.

Claims

1. A Schiff base compound having the structural formula III: (III)。 2. A method for preparing the Schiff base compound according to claim 1, comprising: 。 3.(1) Dissolve the compound of formula II 4-(1,2,4-triazol-1-ylmethyl)aniline in a solvent; (2) Add the solution of Formula I 1-pyrene formaldehyde and Formula II 4-(1,2,4-triazol-1-ylmethyl)aniline compound into the reaction apparatus, heat to reflux, and react for 5 h; (3) Cooling, filtering, washing, and recrystallization yield the target compound.

4. The method for preparing the Schiff base compound according to claim 2, characterized in that, The solvent used in step (1) is selected from anhydrous ethanol.

5. The method for preparing the Schiff base compound according to claim 2, characterized in that, Step (2) also includes monitoring the reaction process using TLC.

6. The method for preparing the Schiff base compound according to claim 2, characterized in that, The molar ratio of raw material I to raw material II is 1.0~1.5:

1.

7. The Schiff base of claim 1, in the application of fluorescent materials and DPPH radical scavenging.

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