CN105712950B - Amides compound and its preparation method and application based on benzothiazole - Google Patents

Abstract

The present invention relates to a kind of amides compound and preparation method thereof based on benzothiazole.The structure of the compound is as shown in logical formula (I), wherein R is-H or-OH；N is the integer of 1-4；R₁It is identical or different, it is independent to be selected from H, C_1‑6Alkyl, C_1‑6Alkoxy, halogen ,-NR₃R₄, aryl, heteroaryl；R₂For C_1‑18Alkyl, aryl, heteroaryl；R₃、R₄It is identical or different, it is independently H, C_1‑6Alkyl, aryl.The invention further relates to application of the compound in terms of organic optical function material.The compound can issue the fluorescence of stronger blue, green or yellow, shining for different colours can be obtained and configuring different ratios, and can be superimposed generation white light.Therefore compound of the present invention is mixed or is adulterated, white light emitting material can be prepared, can apply in the solid luminescents material such as white organic light emitting diode.

Description

Benzothiazole-based amide compounds and preparation method and application thereof

technical field

The present invention relates to benzothiazole derivatives, in particular to benzothiazole-based amide compounds, a preparation method of such compounds and their application in organic small molecule light-emitting materials.

Background technique

Excited-state intramolecular proton transfer (ESIPT) phenomenon exists widely in nature and is one of the most basic and important proton transfer methods in biological and chemical processes. Compared with other organic light-emitting compounds, ESIPT compounds have a unique E-E*-K*-K-E four-level transition behavior, resulting in larger Stokes shift and higher luminous efficiency. Compounds with aggregation-induced luminescence enhancement (AIEE) properties due to hydrogen bonding interactions have a much higher luminescence efficiency at high concentrations or in the aggregated state than in dilute solutions at low concentrations. ESIPT compounds have special photophysical processes and photophysical properties, and are a new class of solid-state (aggregated) organic light-emitting materials with excellent properties.

High-brightness organic solid-state light-emitting materials have good application prospects in the field of electroluminescence, especially in organic white light-emitting diodes. ESIPT compounds with AIEE properties can well solve the problem of aggregated fluorescence quenching (ACQ), so the application of ESIPT compounds in organic white light emitting materials is a very meaningful research direction. White light emitting materials can be mainly divided into two types: single molecule white light emitting materials and multi-molecular white light emitting materials. According to chromaticity, white light can be obtained by superposition of red, green and blue primary colors. As long as the triangle formed by the line segments connecting the color coordinates of the three lights contains white light points, then the three lights can produce white light through reasonable superposition. If the line segment formed by the color coordinates of the two kinds of light passes through the white light point, then the two kinds of light can also generate white light through reasonable superposition.

SUMMARY OF THE INVENTION

The object of the present invention is to provide benzothiazole-based amide compounds.

Another object of the present invention is to provide a preparation method of benzothiazole-based amide compounds.

Another object of the present invention is to provide the use of benzothiazole-based amide compounds for preparing organic small molecule light-emitting materials.

The object of the present invention is achieved through the following technical solutions:

A kind of amide compound based on benzothiazole, its structure is shown in general formula (I):

in,

R is -H or -OH; n is an integer of 1-4;

R ₁ are the same or different, and are independently selected from H, C _1-6 alkyl, C _1-6 alkoxy, halogen, -NR ₃ R ₄ , aryl, heteroaryl;

R ₂ is C _1-18 alkyl, aryl, heteroaryl;

R ₃ and R ₄ are the same or different, and are independently H, C _1-6 alkyl, and aryl.

Said alkyl group is a straight chain or branched chain alkyl group, for example, methyl, ethyl, propyl, butyl, isobutyl, tert-butyl and the like.

The aryl group refers to a monocyclic or polycyclic aromatic group having 6-20 carbon atoms, and representative aryl groups include: phenyl, naphthyl, anthracenyl, pyrenyl and the like.

The heteroaryl group refers to a monocyclic or polycyclic heteroaromatic group having 1-20 carbon atoms and 1-4 heteroatoms selected from N, S, O, and representative heteroaryl groups include: pyrrolyl , pyridyl, pyrimidinyl, imidazolyl, thiazolyl, indolyl, azanaphthyl, etc.

Preferably, in the compound of general formula (I), the amide group and the group R are in the para or meta position.

Preferably, R is -H and meta to the amide group; or R is -OH and meta to the amide group; or R is -OH and para to the amide group.

Preferably, n is 1 or 2.

Preferably, R ₁ are the same or different, and are independently selected from H, C _1-6 alkyl, C _1-6 alkoxy, and aryl.

Preferably, R ₂ is C _1-10 alkyl or aryl.

Further preferably, the compound of general formula (I) can be the following specific compound:

The present invention also provides a method for preparing the compound of the general formula (I), comprising: reacting the compound of the general formula (II) with R ₂ COOH to obtain the compound of the general formula (I):

wherein R, R1, _R2 , _n are as defined above.

According to the present invention, the above reaction is carried out in a solvent environment, and the solvent is preferably a toluene solvent. Preferably, a dehydrating agent such as N,N'-carbonyldiimidazole (CDI) is used to promote the amidation reaction between the amino group and the carboxyl group.

According to the present invention, the above product is separated and purified by recrystallization or silica gel column chromatography.

According to the present invention, the above-mentioned compound of general formula (II) can be prepared by the following method:

wherein R, R ₁ , n are as defined above;

The compound of general formula (III) is reacted with the compound of general formula (IV) to obtain the compound of general formula (II). Preferably, the above reaction is carried out in polyphosphoric acid. Preferably, the above reaction is carried out under argon protection. For the specific synthetic route, please refer to Chinese patent CN102993194 (application number: 201110143095.9) issued by Yang Guoqiang et al.

The compound of the invention has few synthesis steps, short reaction time, convenient purification and simple process.

The compounds of the present invention can respectively emit strong blue, green or yellow fluorescence, and can be mixed in different proportions to obtain different colors of luminescence including white luminescence. For example, the CIE coordinate can be obtained as (0.31, 0.32) of white light. Such compounds can be used in organic small molecule light-emitting materials.

The present invention also provides the use of the compounds of the general formula (I) above, which can be used in organic light-emitting materials. For example in organic light emitting diodes.

According to the present invention, the compound of the general formula (I) can be used to prepare organic light-emitting materials with different colors, such as blue, green, yellow, white and the like.

According to the present invention, a white light emitting material can be obtained by physically mixing or doping different compounds of the general formula (I).

An organic light-emitting material, comprising the compound of general formula (I) described in the present invention.

According to the present invention, the organic light-emitting material includes two or more compounds of the general formula (I) according to the present invention.

Preferably, the organic light-emitting material contains the following three compounds:

Description of drawings

Figure 1 shows the normalized fluorescence emission spectra (λem=340 nm) of the solids of compounds P1s, P2s and P3s prepared in Examples 2-4.

FIG. 2 is a photograph of the films prepared in Examples 5-7 doped with P1s, P2s, and P3s in polymethyl methacrylate under a 365 nm ultraviolet lamp.

3 is the coordinates on the CIE 1931 color space chromaticity diagram (CIE diagram) corresponding to the emission colors of the P1s, P2s, and P3s films prepared in Examples 5-7 doped in polymethyl methacrylate.

Detailed ways

The present invention is illustrated in detail by the following examples. However, those skilled in the art understand that the following embodiments do not limit the protection scope of the present invention. Any improvements and changes made on the basis of the present invention fall within the protection scope of the present invention.

Example 1: Preparation of amine compounds of benzothiazole

Preparation of 4-(benzothiazol-2-yl)aniline (P1), 5-amino-2-(benzothiazol-2-yl)phenol (P2), 4-amino-2-(benzothiazol-2- base) phenol (P3)

It was synthesized according to the method described in Chinese patent CN102993194 (application number: 201110143095.9) issued by Yang Guoqiang et al.

Examples 2-4: Preparation of amide compounds of benzothiazole

Example 2

Preparation of N-[4-(benzothiazole) phenyl] octanamide (P1s), its molecular structure is:

Weigh 2.43g (0.015mol) of N,N'-carbonyldiimidazole (CDI) into a 100mL three-necked flask, then add 50mL of anhydrous toluene and 2.16g (0.015mol) of n-octanoic acid, under argon protection The reaction was stirred at room temperature for half an hour, then the temperature was raised to make the system reflux in toluene for five hours and then the heating was stopped. After cooling to room temperature, 2.26g (0.01mol) of 4-(benzothiazol-2-yl)aniline was added, After stirring the reaction at room temperature for half an hour, the temperature was raised to reflux and the reaction was carried out overnight. The heating was stopped, cooled to room temperature, filtered, and the obtained solid was recrystallized in toluene to obtain a white solid with a yield of 47.2%. ¹ HNMR(400MHz,DMSO)δ10.18(s,1H), 8.12(d,1H), 8.02(t,3H), 7.79(d,2H), 7.52(t,1H), 7.43(t,1H) , 2.34(t, 2H), 1.60(t, 2H), 1.28(t, 8H), 0.86(t, 3H), EI-MS, m/z: 352. The molecular formula is C ₂₁ H ₂₄ N ₂ OS, element Analytical theoretical value: C 71.55, H 6.86, N 7.95; found value: C 71.37, H 6.70, N 8.09.

The compound emits strong blue fluorescence (see Figure 1). Its luminous efficiency in ethyl acetate was 0.25.

Example 3

Preparation of N-[3-hydroxy-4-(benzothiazole) phenyl] octanamide (P2s), its molecular structure is:

4-(benzothiazol-2-yl)aniline in Example 2 was replaced with 5-amino-2-(benzothiazol-2-yl)phenol, and other steps were the same as in Example 2 to obtain a pale yellow solid, The yield was 69.0%. ¹ H NMR (400MHz, CDCl ₃ )δ12.63(s,1H), 7.94(d,1H), 7.88(d,1H), 7.62(d,1H), 7.49(t,1H), 7.39(t, 1H), 7.27(d, 1H), 7.20(d, 2H), 2.38(t, 2H), 1.74(m, 2H), 1.36-1.29(m, 8H), 0.88(t, 3H).EI-MS , m/z: 368. Molecular formula is C ₂₁ H ₂₄ N ₂ O ₂ S, elemental analysis theoretical value: C 68.45, H 6.56, N7.60; measured value: C 68.19, H 6.61, N 7.43.

The compound emits strong green fluorescence (see Figure 1).

Example 4

Preparation of N-[3-(benzothiazole)-4-hydroxyphenyl] octanamide (P3s), its molecular structure is:

The 4-(benzothiazol-2-yl)aniline in Example 2 was replaced with 4-amino-2-(benzothiazol-2-yl)phenol, and other synthetic methods were the same as those in Example 2. The filtered solid was washed three times with a small amount of methanol. The product was purified by silica gel column chromatography to give a pale yellow solid in 51.9% yield. ¹ H NMR (400MHz, CDCl ₃ )δ8.13(s,1H), 7.99(d,1H), 7.90(d,1H), 7.52-7.48(m,1H), 7.43-7.39(m,1H), 7.33-7.30(m, 1H), 7.15(s, 1H), 7.05(d, 1H), 2.38(t, 2H), 1.76(t, 2H), 1.39-1.30(m, 9H), 0.89(t, 3H).EI-MS, m/z: 368. Molecular formula is C ₂₁ H ₂₄ N ₂ O ₂ S, elemental analysis theoretical value: C 68.45, H 6.56, N 7.60; measured value: C 68.10, H 6.54, N 7.40 .

This compound emits strong yellow fluorescence (see Figure 1).

Examples 5-7: Preparation of films doped with compounds prepared in Examples 2-4 in polymethyl methacrylate

Example 5

Weigh 0.3g of polymethyl methacrylate (PMMA, molecular weight is 15000), dissolve in 6g of dichloromethane, and then add 3mg of N-[4-(benzothiazole)phenyl] prepared in Example 2 Caprylamide, stir well, mix well, transfer the solution to a petri dish, cover the petri dish, put it in a fume hood, let the solvent slowly evaporate completely, and prepare N-[4-(benzothiazole)benzene [0044] [0012] thin films doped with PMMA. The mass ratio of compound to PMMA is 1:100.

The film was cut into small squares and emitted blue light under a UV lamp at 365 nm (see Figure 2).

Example 6

Replace the N-[4-(benzothiazole)phenyl]octamide in Example 5 with the N-[3-hydroxy-4-(benzothiazole)phenyl]octamide prepared in Example 3, and the other The steps and methods are the same as those in Example 5. The N-[3-hydroxy-4-(benzothiazole)phenyl]octylamide doped film in PMMA was prepared.

The film was cut into small squares and glowed green under a 365 nm UV lamp (see Figure 2).

Example 7

Replace the N-[4-(benzothiazole)phenyl]octamide in Example 5 with the N-[3-(benzothiazole)-4-hydroxyphenyl]octamide prepared in Example 4, Other steps and methods are the same as in Example 5. The N-[3-(benzothiazole)-4-hydroxyphenyl]octamide doped film in PMMA was prepared.

The film was cut into small squares and glowed yellow under a 365 nm UV lamp (see Figure 2).

The luminescence of the three films was detected by a fluorescence spectrometer, and the luminescence data were converted into coordinate points on the CIE 1931 color space chromaticity diagram (CIE diagram) (see Figure 3). Connect the three coordinate points into line segments to form a triangle. As can be seen from the figure, this triangle contains the white light emitting area. Therefore, the compounds P1s, P2s, and P3s are mixed or doped in an appropriate ratio, and a white light emitting material can be modulated.

Claims (1)

1. An organic light-emitting material, wherein the organic light-emitting material comprises the following three compounds: