阅读说明：本技术 一种3-(2-溴-9-苯基-9h-芴-9-基)吡啶的合成方法 (Synthetic method of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine ) 是由 姜珍华 易炜 邵昌尧 高然 司洪福 周法政 王魁 闫浩磊 于 2021-06-21 设计创作，主要内容包括：本发明公开了一种3-(2-溴-9-苯基-9H-芴-9-基)吡啶的合成方法,包括以下步骤：a.5-溴-2-碘苯基二苯甲酮的合成,b.5-溴-(2-联苯)基二苯甲酮的合成,c.(4-溴-2-[1,1’-联苯]基)苯基甲醇的合成,d.3-(2-溴-9-苯基-9H-芴-9-基)吡啶的合成上述四个步骤,相对于同领域生产方式其降低了生产成本,而且合成收率高,适合工业化进行3-(2-溴-9-苯基-9H-芴-9-基)吡啶的生产制造。(The invention discloses a synthetic method of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine, which comprises the following steps: the synthesis method comprises the following four steps of synthesis of 5-bromo-2-iodophenyl benzophenone, synthesis of 5-bromo- (2-biphenyl) diphenyl ketone, synthesis of (4-bromo-2- [1, 1' -biphenyl ] phenyl methanol and synthesis of d.3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine, and is suitable for industrial production and manufacture of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine.)

1. A synthetic method of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine is characterized by comprising the following steps: the method comprises the following steps:

a. adding dichloromethane, thionyl chloride, 2-iodine-5-bromobenzoic acid and catalytic amount of N, N-dimethylformamide into a reaction vessel, heating to 40 ℃, stopping heating after reacting for 5-6 hours, evaporating dichloromethane, adding benzene and aluminum trichloride, heating to 80 ℃, reacting for 5-6 hours, dropwise adding water for quenching reaction, adjusting the pH to 5-6 by using a sodium carbonate solution, stirring for liquid separation, evaporating an organic phase to dryness, and drying to obtain light yellow solid 5-bromine-2-iodophenyl benzophenone;

b. dissolving the obtained 5-bromo-2-iodophenyl benzophenone in toluene and ethanol, adding phenylboronic acid and a potassium carbonate solution, adding palladium tetratriphenylphosphine under the protection of nitrogen, heating to 78 ℃, reacting for 3-4 hours, cooling to room temperature, separating liquid, and drying an organic phase to obtain 5-bromo- (2-biphenyl) benzophenone;

c. under the protection of nitrogen, adding tetrahydrofuran and 3-bromopyridine into a reaction container, cooling to-78 ℃, dropwise adding n-butyllithium n-hexane solution, stirring for 0.5 hour, adding 5-bromo- (2-biphenyl) benzophenone, carrying out heat preservation reaction for 5 hours at-78 ℃, quenching the reaction by using saturated ammonium chloride solution, carrying out liquid separation after the reaction is finished, and evaporating an organic phase to dryness to obtain (4-bromo-2- [1, 1' -biphenyl ] yl) phenylmethanol;

d. dissolving the obtained (4-bromo-2- [1, 1' -biphenyl ] yl) phenyl methanol in acetic acid, adding concentrated hydrochloric acid, heating to 100 ℃, reacting for 2-3 hours, stopping heating, cooling to room temperature, filtering to obtain a white solid, and pulping with ethanol to obtain the white solid, namely 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine.

2. The method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine according to claim 1, wherein: in the step a, the molar ratio of 2-iodine-5-bromobenzoic acid to thionyl chloride to aluminum trichloride is 1: 1.1- -1.4: the dosage of the 1-1.25, N, N-dimethylformamide is 0.5-2 percent of the 2-iodine-5-bromobenzoic acid.

3. The method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine according to claim 1, wherein: in the step b, the molar ratio of the 5-bromo-2-iodophenyl benzophenone to the phenylboronic acid, the potassium carbonate and the tetratriphenylphosphine palladium is 1: 1- -1.1: 1.2- -1.5: 0.002- -0.01.

4. The method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine according to claim 1, wherein: in the step c, the mol ratio of the 3-bromopyridine to the n-butyllithium to the 5-bromo- (2-biphenyl) benzophenone is 1: 1- -1.3: 0.8- -1.

5. The method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine according to claim 1, wherein: in the step d, the mass ratio of (4-bromo-2- [1, 1' -biphenyl ] yl) phenylmethanol to concentrated hydrochloric acid is 1: 0.05- -0.2.

Technical Field

The invention relates to the technical field of luminescent material manufacturing, in particular to a synthetic method of 3- (2-bromine-9-phenyl-9H-fluorene-9-yl) pyridine.

Background

Description of the background of the inventionthe art to which the present invention pertains is presented solely for the purpose of illustration and understanding the context of the present invention and is not to be construed as an admission or admission that the applicant is aware or appreciates that such prior art forms part of the present invention as the first filing date of the present application.

Organic Electroluminescent (EL) devices have been attracting attention as solid-state light-emitting type inexpensive large-area full-color display devices. The organic electroluminescent device (OLED) has the advantages of low driving voltage, high brightness and luminous efficiency, wide luminous viewing angle, infinitely high color contrast, high response speed, high ultrathin flexibility, foldability and the like, and is known as the flat panel display technology in the twenty-first century. The organic EL element is composed of a pair of opposed electrodes and a light-emitting layer sandwiched therebetween, and when an electric field is applied between the electrodes, electrons are injected from the cathode side and holes are injected from the anode side, the electrons and the holes are recombined in the light-emitting layer to form excitons, and the excitons transition from an excited state to a ground state and emit photons. Early organic EL devices had high driving voltage, low luminous efficiency, and poor durability. The current research and development mainly focuses on increasing the rigidity and stability of the material structure and prolonging the service life of the device. Patent WO2018038401a1 proposes that the fluorene skeleton has a high charge mobility as a material for an organic EL element, and particularly as a hole transport material, and that the organic EL element can be further reduced in voltage and prolonged in element life.

In the related patent technologies of OLEDs in recent years, a large number of luminescent materials containing fluorene structures have been developed, such as 2-bromo-9, 9 '-dimethylfluorene, 2-bromo-9, 9' -diphenylfluorene, etc., and fluorene derivatives containing aromatic heterocyclic ring substitutions have been reported.

Disclosure of Invention

The invention aims to solve the technical problem of providing a safe, green, technically feasible and simple-operation method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine.

In order to solve the technical problems, the technical scheme of the invention is as follows: a synthetic method of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine comprises the following steps:

a. adding dichloromethane, thionyl chloride, 2-iodine-5-bromobenzoic acid and catalytic amount of N, N-dimethylformamide into a reaction vessel, heating to 40 ℃, stopping heating after reacting for 5-6 hours, evaporating dichloromethane, adding benzene and aluminum trichloride, heating to 80 ℃, reacting for 5-6 hours, dropwise adding water for quenching reaction, adjusting the pH to 5-6 by using a sodium carbonate solution, stirring for liquid separation, evaporating an organic phase to dryness, and drying to obtain light yellow solid 5-bromine-2-iodophenyl benzophenone;

b. dissolving the obtained 5-bromo-2-iodophenyl benzophenone in toluene and ethanol, adding phenylboronic acid and a potassium carbonate solution, adding palladium tetratriphenylphosphine under the protection of nitrogen, heating to 78 ℃, reacting for 3-4 hours, cooling to room temperature, separating liquid, and drying an organic phase to obtain 5-bromo- (2-biphenyl) benzophenone;

c. under the protection of nitrogen, adding tetrahydrofuran and 3-bromopyridine into a reaction container, cooling to-78 ℃, dropwise adding n-butyllithium n-hexane solution, stirring for 0.5 hour, adding 5-bromo- (2-biphenyl) benzophenone, carrying out heat preservation reaction for 5 hours at-78 ℃, quenching the reaction by using saturated ammonium chloride solution, carrying out liquid separation after the reaction is finished, and evaporating an organic phase to dryness to obtain (4-bromo-2- [1, 1' -biphenyl ] yl) phenylmethanol;

d. dissolving the obtained (4-bromo-2- [1, 1' -biphenyl ] yl) phenyl methanol in acetic acid, adding concentrated hydrochloric acid, heating to 100 ℃, reacting for 2-3 hours, stopping heating, cooling to room temperature, filtering to obtain a white solid, and pulping with ethanol to obtain the white solid, namely 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine.

In a preferred embodiment, the molar ratio of 2-iodo-5-bromobenzoic acid, thionyl chloride and aluminum trichloride in step a is 1: 1.1- -1.4: the dosage of the 1-1.25, N, N-dimethylformamide is 0.5-2 percent of the 2-iodine-5-bromobenzoic acid.

As a preferred embodiment, the molar ratio of 5-bromo-2-iodophenylbenzophenone to phenylboronic acid, potassium carbonate, and tetratriphenylphosphine palladium in step b is 1: 1- -1.1: 1.2- -1.5: 0.002- -0.01.

As a preferred embodiment, the molar ratio of 3-bromopyridine to n-butyllithium, 5-bromo- (2-biphenyl) ylbenzophenone in step c is 1: 1- -1.3: 0.8- -1.

In a preferred embodiment, the mass ratio of (4-bromo-2- [1, 1' -biphenyl ] yl) phenylmethanol to concentrated hydrochloric acid in step d is 1: 0.05- -0.2.

The beneficial effects obtained by adopting the technical scheme are as follows: compared with the production mode in the same field, the method reduces the production cost, has high synthesis yield, and is suitable for industrial production and manufacture of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of the reaction process of the present invention.

FIG. 2 is a scheme showing the preparation of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine of the present invention¹H NMR (CDCl3) chart.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

The invention is further described with reference to the accompanying drawings, so as to enable the person skilled in the art to better implement the invention, and the embodiment of the invention is a method for synthesizing 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine, which comprises the following steps:

a.5-bromo-2-iodophenyl benzophenone synthesis

Adding 200mL dichloromethane, 2-iodine-5-bromobenzoate methyl (34.1g, 0.1mol), thionyl chloride (14.3g, 0.12mol), 0.5mL N, N-dimethylformamide into a reaction vessel provided with a mechanical stirrer, a reflux condenser tube, a constant pressure dropping funnel and a thermometer, heating to 40 ℃, stirring for 5-6 hours, stopping heating, TLC tracing reaction, evaporating dichloromethane, adding 100mL benzene, anhydrous aluminum trichloride (13.3g, 0.1mol), heating to 80 ℃, stirring for 5-6 hours, TLC tracing reaction, cooling to room temperature, dropwise adding water to quench reaction, adjusting pH to 5-6 with sodium carbonate solution, stirring for liquid separation, extracting an aqueous phase with ethyl acetate for 2 times, combining organic phases, evaporating an organic phase to dryness, drying to obtain pale yellow solid 5-bromine-2-iodophenyl benzophenone 34.1g, the yield thereof was found to be 88%. Ms (ei): m/z: 387.01[ M ]⁺]。Anal.calcd for C₁₃H₈BrIO(％)：C,40.35；H,2.08；found:C40.38，H 2.10。

b.5-bromo- (2-biphenyl) benzophenone synthesis

Under the protection of nitrogen, the nitrogen gas is fed into a constant-pressure condenser equipped with a mechanical stirrer and a reflux condenser150mL of toluene, 75mL of ethanol, 75mL of water, 5-bromo-2-iodophenylbenzophenone (34.1g, 0.088mol), phenylboronic acid (10.73g, 0.088mol), potassium carbonate (24.29g, 0.176mol), tetratriphenylphosphine palladium (1.02g, 0.88mmol) are added into a reaction vessel of a pressure dropping funnel and a thermometer, the mixture is heated to 78 ℃ for reaction for 3-4 hours, TLC tracking reaction is finished, the mixture is cooled to room temperature, liquid separation is carried out, organic phase is dried, the mixture is concentrated to dryness, a solid is pulped for 2-3 hours by using 2 times of ethanol, and the solid is filtered and dried to obtain 27.3g of 5-bromo- (2-biphenyl) yl benzophenone with the yield of 92%. Ms (ei): m/z: 337.22[ M ]⁺]。Anal.calcd for C₁₉H₁₃BrO(％)：C,67.67；H,3.89；found:C67.63，H 3.85。

c. Synthesis of (4-bromo-2- [1, 1' -biphenyl ] yl) phenylmethanol

Adding 250mL of anhydrous tetrahydrofuran and 3-bromopyridine (12.39g, 0.081mol) into a reaction vessel provided with a mechanical stirrer, a constant pressure dropping funnel and a thermometer under the protection of nitrogen, cooling to-78 ℃ by using a dry ice acetone cooling bath, dropwise adding 2.5M n-butyllithium (35.5mL, 0.089mol), keeping the temperature and stirring for 30 minutes, adding 5-bromo- (2-biphenyl) benzophenone (27.3g, 0.081mol) synthesized in the previous step, keeping the temperature and reacting for 5-6 hours, finishing TLC tracking reaction, quenching the reaction by using 80mL of saturated ammonium chloride aqueous solution, separating, and evaporating an organic phase to dryness to obtain (4-bromo-2- [1, 1' -biphenyl)]Yl) phenylmethanol 31.7g, yield 94%. Ms (ei): m/z: 416.32[ M ]⁺]。Anal.calcd for C24H18BrNO(％)：C,69.24；H,4.36；N,3.36；found:C 69.26，H 4.33,N,3.33。

Synthesis of 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine

200ml of glacial acetic acid, (4-bromo-2- [1, 1' -biphenyl) was added to a reaction vessel equipped with a mechanical stirrer, reflux condenser, and thermometer]Phenyl methanol (31.7g, 0.076mol), concentrated hydrochloric acid 15g with concentration of 37%, heating to 100 ℃, reacting for 2-3 hours, monitoring by TLC to finish the reaction, stopping heating, cooling to room temperature, filtering to obtain a white-like solid, and pulping by ethanol to obtain 29.42g of white solid 3- (2-bromo-9-phenyl-9H-fluoren-9-yl) pyridine with yield of 93%. Ms (ei): m/z: 416.32[ M ]⁺]。Anal.calcd for C₂₄H₁₆BrN(％)：C,72.37；H,4.05；N,3.52；found:C 72.34，H 3.99,N,3.49。¹H NMR(CDCl₃,400MHz,298K):δ8.44(m,1H,ArH),8.28(m,1H,ArH),7.90(m,1H,ArH),7.66(m,1H,ArH),7.61(m,1H,ArH),7.50(m,1H,ArH),7.42(m,1H,ArH),7.34(m,2H,ArH),7.27(m,5H,ArH),7.09(m,2H,ArH)。

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. It will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, and the scope of protection is still within the scope of the invention.