阅读说明：本技术 一种多环双酮稠环分子的制备方法 (Preparation method of polycyclic diketone fused ring molecule ) 是由 邵静 孟维利 屈苏平 于 2020-12-31 设计创作，主要内容包括：本发明提供一种多环双酮稠环分子的制备方法,通过对反应前驱体的结构进行优化,在前驱体的酯基上引入能够能够提供空间位阻的支化烷基侧链,找到了一条更加简单制备难溶的多环(环数≧7)双酮稠环分子的方法。对于环数≧7、需要发生两次分子内傅-克酰基化反应的多环双酮稠环分子的制备,简化了合成步骤,提高了目标产物的得率,降低了对操作环境的要求。(The invention provides a preparation method of a polycyclic diketone and condensed ring molecule, which is a method for more simply preparing an insoluble polycyclic (the number of rings is not less than 7) diketone and condensed ring molecule by optimizing the structure of a reaction precursor and introducing a branched alkyl side chain capable of providing steric hindrance to an ester group of the precursor. For the preparation of polycyclic diketone condensed ring molecules with the ring number not less than 7 and needing two intramolecular Friedel-crafts acylation reactions, the synthesis steps are simplified, the yield of target products is improved, and the requirements on the operation environment are reduced.)

1. A preparation method of polycyclic diketone fused ring molecules is characterized by comprising the following steps:

mixing 1 mol part of the reaction precursor (4) and 5-7 mol parts of hydrated p-toluenesulfonic acid, dissolving in o-dichlorobenzene, and reacting at 170-190 ℃ for 10-16 h under the protection of argon. After the reaction is cooled to room temperature, filtering the reaction mixture, sequentially washing a filter cake for at least 2 times by using o-dichlorobenzene, chloroform and acetone, extracting the obtained product for 10-12 hours by using acetone, performing suction drying to obtain a crude product, and further purifying to obtain a target product, namely the polycyclic diketone and diketone fused ring compound (3);

R₁represents-H orR₂represents-H orR₁And R₂Only one isR₁≠R₂；

R₃Represents a branched alkyl side chain with the carbon number of more than or equal to 8;

ar represents monocyclic aryl or condensed ring aryl which is easy to generate ortho-position substitution and has a mirror symmetry or central symmetry structure, Ar ' represents monocyclic aryl, substituted monocyclic aryl, condensed ring aryl or substituted condensed ring aryl which have ortho-position reaction active sites, and Ar is not necessarily equal to Ar ', and the sum of the number of aromatic ring rings of Ar and the number of aromatic ring rings of Ar ' is more than or equal to 5.

2. The method of making a polycyclic diketone fused ring molecule according to claim 1, wherein: r₃Is isooctyl, 2-butyloctyl or 2-octyldodecyl.

3. A method of making a polycyclic diketone fused ring molecule according to claim 1 or 2, wherein:

ar is selected from

Ar' is selected from

4. The method of making a polycyclic diketone fused ring molecule according to claim 3, wherein: r₁is-H, R₂Is thatR₃Is isooctyl, Ar isAr' is

5. The method of making a polycyclic diketone fused ring molecule according to claim 3, wherein: r₁Is thatR₂is-H, R₃Is isooctyl, Ar isAr' is

Technical Field

The invention relates to the field of chemical industry, in particular to a preparation method of polycyclic diketone fused ring molecules.

Background

The fused ring unit containing the diketone structure can be directly used as an organic photoelectric material, can also be chemically modified at the position of the diketone to obtain a quinoid structure or fluorene ring structure unit, and can also be used as a structure unit to construct a polymer photoelectric material. As the basic structural unit, synthesis of a fused ring unit having a ketone structure (═ O) is important. As shown in the formula I, the arone structure is generally prepared by Friedel-crafts reaction catalyzed by protonic acid (such as concentrated sulfuric acid, polyphosphoric acid) or Lewis acid (boron trifluoride, aluminum trichloride), and the reaction precursor of the arone structure mainly comprises acyl chloride or carboxylic acid. However, the friedel-crafts acylation of acyl chloride and carboxylic acid generally requires lower reaction temperature, and puts higher requirements on the solubility of the precursor (1) or the intermediate product (2) of a polycyclic reaction system (shown in the reaction formula II); the Friedel-crafts acylation reaction based on methyl ester or ethyl ester (in a reaction formula II, R ═ methoxy or ethoxy) reported in the literature at present has the defects that the system temperature is too low (-78 ℃) by adopting Lewis acid catalysis, and the solubility of the polycyclic and poly-ketone fused ring molecular intermediate is insufficient; the system adopting concentrated sulfuric acid or trifluoromethanesulfonic acid has high corrosivity; when R is equal to ethoxy, the reaction system can be completely dissolved after being heated to 100 ℃, but after the system is reacted for 36 hours at 180 ℃, only 15% of crude product can be obtained by filtration, the yield is low, and the subsequent purification is difficult due to more by-products or impurities.

Therefore, a simpler and safer synthetic method is urgently needed for a polycyclic (ring number ≧ 7) diketone fused ring system with poor solubility.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a preparation method of polycyclic diketone fused ring molecules, and a method for preparing difficultly soluble polycyclic diketone (ring number is not less than 7) diketone fused ring molecules more simply is found by optimizing the structure of a precursor of a Friedel-crafts acylation reaction. The preparation of polycyclic diketone condensed ring molecules with the ring number not less than 7 and needing two intramolecular Friedel-crafts acylation reactions simplifies the synthesis steps and reduces the requirements on the operation environment.

In order to solve the technical problems, the invention adopts the following technical scheme: the preparation method of the polycyclic diketone fused ring molecule comprises the following steps: mixing 1 mol part of the reaction precursor (4) and 5-7 mol parts of hydrated p-toluenesulfonic acid, dissolving in o-dichlorobenzene, and reacting at 170-190 ℃ for 10-16 h under the protection of argon. After the reaction is cooled to room temperature, filtering the reaction mixture, sequentially washing a filter cake for at least 2 times by using o-dichlorobenzene, chloroform and acetone, extracting the obtained product for 10-12 hours by using acetone, performing suction drying to obtain a crude product, and further purifying to obtain a target product, namely the polycyclic diketone and diketone fused ring compound (3);

R₁represents-H orR₂represents-H orR₁And R₂Only one isR₁≠R₂；

R₃Represents a branched alkyl side chain with the carbon number of more than or equal to 8;

ar represents monocyclic aryl or condensed ring aryl which is easy to generate ortho-position substitution and has a mirror symmetry or central symmetry structure, Ar ' represents monocyclic aryl, substituted monocyclic aryl, condensed ring aryl or substituted condensed ring aryl which have ortho-position reaction active sites, and Ar is not necessarily equal to Ar ', and the sum of the number of aromatic ring rings of Ar and the number of aromatic ring rings of Ar ' is more than or equal to 5.

Preferably, R₃Selected from isooctyl, 2-butyloctyl, 2-octyldodecyl or 3-methylhexyl;

ar is selected from

Ar' is selected from

Specifically, R₁is-H, R₂Is thatR₃Is isooctyl, Ar isAr' isOr R₁Is thatR₂is-H, R₃Is isooctyl, Ar isAr' is

The experimental results demonstrate that steric hindrance can be provided only by introducing a branched alkyl side chain (R) on the reaction precursor₃) The ester group can directly and efficiently complete intramolecular Friedel-crafts acylation reaction to obtain the indissolvable polycyclic diketone condensed ring molecules. Compared with the literature report, the synthesis method simplifies the synthesis steps and improves the yield of the target product. And the introduced ester group side chain containing a branching site solves the problem of difficult dissolution of an intermediate product, so that the method can be used for synthesizing the diketone condensed ring molecules with more rings (the ring number is not less than 7).

The preparation method of the polycyclic diketone condensed ring molecule of the invention introduces a functional group R with large steric hindrance into an ester group₃Instead of methyl or ethyl, the solubility of the reaction precursor and the semi-reaction intermediate product is improved, thereby improving the yield of the target product. And the aromatic ester substituted by the branched side chain is directly subjected to Friedel-crafts acylation reaction, so that the step of converting the ester saponification reaction into acid and then converting the acid into acyl chloride is omitted, and an effective method for synthesizing the insoluble polycyclic (the number of rings is not less than 7) diketone condensed ring molecule is provided. The aromatic ketone product can be directly used as an organic thin film transistor material, and can also be used for constructing other organic photoelectric materials through further chemical modification.

Drawings

FIG. 1 is an infrared absorption spectrum of the reaction precursor (5).

FIG. 2 is an infrared absorption spectrum of the objective product (6).

FIG. 3 is a NMR spectrum of the objective product (6).

FIG. 4 is a NMR spectrum of the product (9).

Detailed Description

The invention is further described below with reference to the following examples:

example 1: r₁＝-H，R₃＝—CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃(isooctyl group) in the presence of a catalyst,

the reaction precursor (5) (537.7mg, 0.82mmol) and p-toluenesulfonic acid hydrate (780mg, 4.1mmol) were mixed and dissolved in 180mL o-dichlorobenzene and reacted at 180 ℃ for 12h under the protection of argon. After the reaction was cooled to room temperature, the reaction mixture was filtered and the filter cake was washed 2 times with o-dichlorobenzene, chloroform and acetone in that order, and the resulting product was extracted with acetone for 10h and dried by suction to give 285mg of a brown crude product (Y ═ 88%). The crude product is further purified by a vacuum sublimation device, and the dark green product 213mg at the stage of 135-145 ℃ is collected, namely the yield of the target product, namely the heptacyclic diketone condensed ring molecule (6), is 66%. Dissolving the target product (6) of 2mg/mL in deuterated ethane and carrying out high temperature treatment¹H NMR test (solubility of target product is too low to calculate coupling constant).¹H NMR(400MHz,C₂D₂Cl₄,δ):8.184(d,2H),7.878(s,2H),7.527～7.330(m,6H)。

As can be seen from the infrared absorption spectra (fig. 1, fig. 2): ketocarbonyl groupThe peak of the stretching vibration is 1699.17cm^-1Carbonyl group of esterThe peak of the stretching vibration is 1724.28cm^-1(ii) a And the ester group is 1400-1000cm^-1The fingerprint area has obvious absorption peaks, mainly comprises peak values such as bending vibration of saturated C-H bonds, stretching vibration of C-O bonds, framework vibration of C-C single bonds and the like, and the target molecules (6) are weakly absorbed in the area, so that the molecular structure is determined.

In the experimental process, when the precursor (5) is reacted under the catalysis of p-toluenesulfonic acid, the system is completely dissolved when the temperature is raised to 50 ℃, and a brown crude product is obtained after reaction for 12 hours at 180 ℃ (the structure of the product is verified through vacuum sublimation and purification). Then, the temperature of the reaction system was lowered, and it was found that when the temperature was lowered to 160 ℃, the reaction time was prolonged to 36 hours, but the yield of the insoluble crude product was lowered to 37%. It is presumed that: introduction of isooctyl radical (R)₃) The solubility of the reaction intermediate is improved.

Example 2:R₂＝-H，R₃＝—CH₂CH(CH₂CH₃)CH₂CH₂CH₂CH₃(isooctyl group) in the presence of a catalyst,

precursor (7) (612.8mg, 1mmol) and p-toluenesulfonic acid hydrate (951.2mg, 5mmol) were mixed and dissolved in 20mL o-dichlorobenzene and reacted at 180 ℃ for 12h under argon protection. After the reaction was cooled, the reaction mixture was filtered, the filter cake was washed 2 times with o-dichlorobenzene, chloroform and acetone in that order, and the resulting product was extracted with acetone for 10h and dried by suction to give 323.5mg of dark brown crude product (8) (Y ═ 82%).

The crude product (8) was dispersed in 50mL of dry tetrahydrofuran, and slowly dropped into 19mL of a tetrahydrofuran solution of lithium triisopropylsilyl (TIPS-Li 1.9mmol) after the reaction, and the reaction was carried out at-78 ℃ for 2 hours. After the reaction system naturally warmed to room temperature, 1mL of deionized water was added and the reaction was continued for 10 min.The reaction mixture was poured into 300mL of water, extracted 3 times with 150mL of dichloromethane, washed three times with saturated brine, dried over anhydrous magnesium sulfate, rotary evaporated to remove the solvent, and vacuum dried to give 566.8mg of a purplish black crude product. After flash column separation with dichloromethane as eluent, 480mg of the magenta product (9) was obtained by recrystallization (tetrahydrofuran: petroleum ether ═ 1:1), with an overall yield of about 61% for the two steps.¹H NMR(400MHz,CHCl₃,δ):7.352(t,2H),7.256(m,4H),7.131(m,4H)，1.201-1.384(m,96H)。

(note: the purple-red product (9) was deteriorated during the separation by acidic and neutral liquid chromatography columns, possibly affecting the final reaction yield; and the chloroform solution of the purple-red product (9) was remarkably discolored after one day at room temperature, which further confirmed the structure of the product (this quinoid structure was poor in stability).