KR102605281B1 - Amide pentamer and method for preparing thereof - Google Patents

Abstract

The present invention provides an amide pentamer represented by the following formula (1).
[Formula 1]

(In the above formula,
A ¹ , A ² , and B ² are each independently selected from a substituted or unsubstituted C6 to C24 aromatic ring, a substituted or unsubstituted C6 to C24 aliphatic ring, or a substituted or unsubstituted C4 to C24 heterocycle. Contains rings of more than one species,
The ring may be a single ring or a condensed ring, or two or more rings may be singlely bonded to each other, or -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH) -, -Si(CH ₃ ) ₂ -, -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' are a C4 to C10 aliphatic ring. formed) or connected to a fluorenyl group.)

Description

Amide pentamer and method for preparing the same}

The present invention relates to raw material compounds for producing polyamidoimide, and more specifically to amide pentamers, intermediates thereof, and methods for producing them.

Polyimide ('PI') is a copolymer with a repeating structure of imide rings, and is generally prepared by polymerizing an aromatic dianhydride compound and an aromatic diamine compound to produce a polyamic acid derivative. It is manufactured by ring-closure dehydration at high temperature and imidization.

Meanwhile, polyamideimide ('PAI') is a copolymer that has both an imide ring repeating structure and an amide repeating structure, and is manufactured by polymerizing aromatic dianhydride, aromatic diamine, and aromatic dicarbonyl compound. .

PI has a rigid aromatic main chain and a chemically stable imide ring, so it has the advantage of excellent mechanical strength, heat resistance, chemical resistance, weather resistance, and insulation properties. However, it is insoluble and infusible, making it difficult to mold. It has the disadvantage of poor performance and processability. PAI can solve these shortcomings of PI by improving solubility and thermoplasticity by introducing an amide structure into PI.

PI and PAI are widely used in the automotive, aerospace, and electrical and electronic materials fields, and recently, research on their use in the display, solar cell, and memory fields is actively underway. In particular, PI and PAI are lighter and more flexible than glass substrates, so they are very useful for flexible displays, for which demand has recently increased.

However, PI and PAI generally have a dark brown color due to the charge transfer complex (CTC) effect occurring in the imide ring, which imposes certain limitations in the display field where a high level of colorless transparency is required.

The CTC effect occurs when the π electrons of the benzene ring present in the main chain of the imide ring are transferred to the adjacent main chain, resulting in a change in energy level, and the light at the absorbed energy wavelength changes accordingly. In the case of general polyimide, as it absorbs light in the visible range between 400 nm and 500 nm, its color becomes yellow or red.

In order to manufacture colorless and transparent PI and PAI for displays, it is essential to suppress or reduce the CTC effect.

Methods for reducing the CTC effect, which is a disadvantage of aromatic PI and PAI, include 1) adding relatively strong electron withdrawing groups such as -CF ₃ and -F to aromatic dianhydride compounds and/or aromatic diamine compounds. group) to limit the movement of π electrons in the PI main chain to lower the resonance effect, and 2) adding -O-, -S-, -SO ₂ - to aromatic dianhydride compounds and/or aromatic diamine compounds. There is a method to reduce the CTC effect between molecules by introducing a curved structure such as -CO- to disrupt the stacking of molecules.

A variety of aromatic dianhydride compounds that can reduce the CTC effect are known, but 6FDA and BPADA are representative examples.

A variety of aromatic diamine compounds that can reduce the CTC effect are known, but TFDB is a representative example.

Meanwhile, during PAI polymerization, the dicarbonyl compound and the diamine compound react with each other to form an amide bond and produce an acid. When a base is added to remove the acid, the base reacts with the dicarbonyl compound and turns yellow. Occurs. If no base is added, the resulting acid reacts with the diamine compound to form a salt and no more amide bonds are formed. Therefore, during PAI polymerization, dicarbonyl compounds do not participate 100% in the reaction and some remain, and it is very difficult to remove these dicarbonyl compounds from the synthesized polymer.

Therefore, it is necessary to maximize the reaction participation of dicarbonyl compounds during PAI polymerization and minimize the amount of unreacted dicarbonyl compounds to prevent yellow coloring and effectively remove unreacted dicarbonyl compounds.

To solve this problem, if a diamine precursor into which an amide group is introduced is prepared by reacting a diamine compound with a dicarboxyl compound in advance, not only will the participation of dicarbonyl in the reaction be maximized, but also the unreacted dicarbonyl compound in a low molecular state can be effectively removed. It can be removed.

Japanese Patent Laid-Open No. 2010-180292 discloses a method of producing PAI by pre-synthesizing a diamine compound into which an amide group is introduced as follows, and then using this as a precursor of PAI and performing an imide reaction with a dianhydride compound.

The Japanese patent describes that an amide trimer combining two diamine molecules and one terephthalic acid molecule can be produced by reacting an aromatic diamine compound with terephthalic acid. However, as a result of the experiment, the composite was not an amide trimer but an amide oligomer ( It was confirmed that amide oligomer) was produced.

Republic of Korea Patent Publication No. 10-2017-0059900 well supports the above facts. The Korean patent is to prepare an amide oligomer having an amide structural unit by reacting TFDB (2,2'-bis(trifluoromethyl)benzidine) with TPC (terethphaloyl chloride) as follows, and then using this as a precursor to form a dianhydride compound and A method for producing PAI through imide reaction is disclosed.

Compounds prepared by the above-described prior art may be dimers, trimers, tetramers, pentamers, hexamers, and heptamers depending on the number of amide bonds. ), octamer, and decamer, etc., are a mixture of various oligomers, so there are limitations as a raw material for polyamidoimide that requires precise physical properties. In the prior art, the target compound can be manufactured with a certain purity or higher by controlling the reaction conditions, but there are still limitations in producing high-purity compounds.

Japanese Patent Laid-open No. 2010-180292 Republic of Korea Patent Publication No. 10-2017-0059900

The purpose of the present invention is to provide a high purity amide pentamer as a raw material for polyamideimide.

The present invention provides an amide pentamer represented by the following formula (1).

[Formula 1]

Meanwhile, the present invention provides an intermediate of the amide pentamer, represented by the following formula (2).

[Formula 2]

In Formulas 1 and 2,

A ¹ , A ² , and B ² are each independently selected from a substituted or unsubstituted C6 to C24 aromatic ring, a substituted or unsubstituted C6 to C24 aliphatic ring, or a substituted or unsubstituted C4 to C24 heterocycle. Contains rings of more than one species,

The ring may be a single ring or a condensed ring, or two or more rings may be singlely bonded to each other, or -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH) -, -Si(CH ₃ ) ₂ -, -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' are a C4 to C10 aliphatic ring. formed) or connected to a fluorenyl group.

In one embodiment, A ¹ and A 2 of Formulas 1 and ² may each be independently selected from Group I below.

(Group Ⅰ)

(In group Ⅰ above,

R ₁ , R ₃ , R ₅ , and R ₇ are each independently -CF ₃ , -CCl ₃ , -CBr ₃ , -CI ₃ , -F, -Cl, -Br, -I, -NO ₂ , -CN, -COCH ₃ , -CO ₂ C ₂ H ₅ It is an electron withdrawing group selected from the group consisting of,

R ₂ , R ₄ , R ₆ , and R ₈ are each independently a substituted or unsubstituted C1 to C10 alkyl group, hydroxy group, alkoxy group, or silyl group,

Q ₁ and Q ₂ are each independently -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH)-, -Si(CH ₃ ) ₂ - , -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' are Each independently is hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' form a C4 to C10 aliphatic ring) or a fluorenyl group,

n ₁ to n ₈ are each independently an integer of 0 to 4, and the number of substituents in each ring is 0 to 4.)

In one embodiment, A ¹ and A 2 of Formulas 1 and ² may each be independently selected from Group II below.

(Group Ⅱ)

In one aspect, B ² in Formulas 1 and 2 may be selected from Group III below.

(Group Ⅲ)

(In group III above,

R ₁ to R ₅ are each independently hydrogen, -CF ₃ , -CCl ₃ , -CBr ₃ , -CI ₃ , -F, -Cl, -Br, -I, a substituted or unsubstituted C1 to C10 alkyl group ego,

n ₁ to n ₃ are each independently an integer of 0 to 4, and the number of substituents in each aromatic ring is 0 to 4.)

In one embodiment, B ² in Formulas 1 and 2 may be selected from Group IV below.

(Group Ⅳ)

In one aspect, the compound of Formula 1 may be a compound of Formula 1a below.

[Formula 1a]

In one aspect, the compound of Formula 2 may be a compound of Formula 2a below.

[Formula 2a]

Meanwhile, the present invention provides a method for preparing an amide pentamer, wherein a compound of the following formula (1) is prepared by reducing a compound of the formula (2) below.

(In the above formula,

A ¹ , A ² , and B ² are each independently selected from a substituted or unsubstituted C6 to C24 aromatic ring, a substituted or unsubstituted C6 to C24 aliphatic ring, or a substituted or unsubstituted C4 to C24 heterocycle. Contains rings of more than one species,

The ring may be a single ring or a condensed ring, or two or more rings may be singlely bonded to each other, or -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH) -, -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' is each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' form a C4 to C10 aliphatic ring) or connected to a fluorenyl group. do.)

In one embodiment, the compound of Formula 2 may be prepared by performing an amide reaction between a compound of Formula 4 below and a compound of Formula 3 below.

In one embodiment, the compound of Formula 3 can be prepared by performing an amide reaction between a compound of Formula 7 below and a compound of Formula 6 to prepare a compound of Formula 5, and then deprotecting the compound of Formula 5.

Meanwhile, the present invention provides an intermediate of amino pentamer, represented by the following formula (3).

[Formula 3]

In one aspect, the compound of Formula 3 may have the following Formula 3a'.

[Formula 3a']

(In the above formula, X is halogen or hydroxy.)

The amide pentamer prepared according to the present invention has a high purity of at least 90%, preferably at least 95%, more preferably at least 98%, and most preferably at least 99%.

While various types of oligomers are produced through chain reactions in the prior art, the present invention can provide amide pentamers of high purity.

The amide pentamer according to the present invention has very high purity and can be usefully used as a raw material for polyamideimide, which requires precise physical properties.

Hereinafter, embodiments of the present invention will be described in detail.

In the present invention, “amide pentamer” refers to a compound composed of five molecules or monomers connected by an amide bond (-CONH-).

In the present invention, “amide trimer” refers to a compound consisting of three molecules or monomers connected by an amide bond.

In the present invention, “pentamer having a nitro group” refers to a compound in which nitro groups are formed at both ends of the amide pentamer.

In the present invention, “intermediate” refers to a compound that can be used in the preparation of amide pentamer and, if necessary, can be used as a starting material.

In the chemical formulas of the present invention, the symbol “*” means connection to an adjacent atom or chemical formula.

The present invention provides an amide pentamer represented by the following formula (1).

[Formula 1]

Meanwhile, the present invention provides an intermediate of an amide pentamer, represented by the following formula (2).

[Formula 2]

In Formulas 1 and 2,

A ¹ , A ² , and B ² are each independently selected from a substituted or unsubstituted C6 to C24 aromatic ring, a substituted or unsubstituted C6 to C24 aliphatic ring, or a substituted or unsubstituted C4 to C24 heterocycle. Contains rings of more than one species,

The ring may be a single ring or a condensed ring, or two or more rings may be singlely bonded to each other, or -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH) -, -Si(CH ₃ ) ₂ -, -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' are each independently hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' are a C4 to C10 aliphatic ring. formed) or connected to a fluorenyl group.

A ¹ and A 2 of Formulas 1 and ² may preferably each be independently selected from Group I below:

(Group Ⅰ)

In group 1 above,

R ₁ , R ₃ , R ₅ , and R ₇ are each independently -CF ₃ , -CCl ₃ , -CBr ₃ , -CI ₃ , -F, -Cl, -Br, -I, -NO ₂ , -CN, -COCH ₃ , -CO ₂ C ₂ H ₅ It is an electron withdrawing group selected from the group consisting of,

R ₂ , R ₄ , R ₆ , and R ₈ are each independently a substituted or unsubstituted C1 to C10 alkyl group, hydroxy group, alkoxy group, or silyl group,

Q ₁ and Q ₂ are each independently -O-, -S-, -SO ₂ -, -CO-, -C(CF ₃ ) ₂ -, -CH(OH)-, -Si(CH ₃ ) ₂ - , -(CH ₂ ) _p - (p=1~10), -(CF ₂ ) _q - (q=1~10), - CR''R'''- (R'' and R''' are Each independently is hydrogen, a substituted or unsubstituted C1 to C10 aliphatic hydrocarbon, a C6 to C20 aromatic hydrocarbon, or R'' and R''' form a C4 to C10 aliphatic ring) or a fluorenyl group,

n ₁ to n ₈ are each independently an integer of 0 to 4, and the number of substituents in each ring is 0 to 4.

More preferably, A ¹ and A 2 of Formulas 1 and ² may each be independently selected from Group II below. The compounds of Group II below are known compounds that can be used in the production of colorless and transparent PI and PAI:

(Group Ⅱ)

Meanwhile, B ² in Formulas 1 and 2 may preferably be selected from Group III below:

(Group Ⅲ)

(In group III above,

R ₁ to R ₅ are each independently hydrogen, -CF ₃ , -CCl ₃ , -CBr ₃ , -CI ₃ , -F, -Cl, -Br, -I, a substituted or unsubstituted C1 to C10 alkyl group; ,

n ₁ to n ₃ are each independently an integer of 0 to 4, and the number of substituents in each aromatic ring is 0 to 4.)

B ² of the above formulas 1 and 2 can be more preferably selected from Group IV below: Compounds of Group 4 below are known formulas that can be used for the preparation of PI and PAI:

(Group Ⅳ)

In one embodiment, the amide pentamer of Formula 1 may be of Formula 1a below.

[Formula 1a]

In one embodiment, the amide pentamer precursor of Formula 2 may be of Formula 2a below.

[Formula 2a]

Meanwhile, the present invention provides a method for producing the amide pentamer of Formula 1 above.

In one embodiment, the amide pentamer of Chemical Formula 1 may be prepared according to Scheme 1 below.

Scheme 1 below shows the overall process for preparing the amide pentamer of Formula 1 using commercially available or easily prepared compounds as starting materials. However, in Scheme 1 below, any intermediate compound, such as one of Formulas 2 to 7, can be used as a starting material. Using any one compound as a starting material is also included in the scope of the present invention.

[Scheme 1]

(In Scheme 1 above,

A ¹ , A ² , and B ² are the same as those of the above-mentioned formulas 1 and 2,

X is halogen or hydroxy,

PG is an ester protecting group.)

The amide pentamer prepared according to the present invention may have a high purity of at least 90%, preferably at least 95%, more preferably at least 98%, and most preferably at least 99%.

In embodiments of the present invention, each process is as follows.

Preparation of compounds of formula 7

In one embodiment. A compound of Formula 7 is prepared by reducing the nitro group of one of the compounds of Formula 8 using a selective reducing agent.

The selective reducing agent is not limited, but sulfide may be used. As the sulfide, an alkali metal hydrogen sulfide compound or metal sulfide may be used. The alkali metal hydrogen sulfide is preferably sodium hydrogen sulfide (NaHS). Metal sulfides include sodium sulfide (Na ₂ S), ammonium sulfide, potassium sulfide (K ₂ S), manganese sulfide (MnS), and iron sulfide (FeS).

The reduction reaction is not limited but may be carried out in the presence of water and/or alcohol.

The reducing agent is not limited, but may be in the form of an aqueous solution, and the alcohol may be methanol, ethanol, n-propanol, or isopropanol. The alcohol is preferably methanol.

The reducing agent is not limited, but may be used in an amount of 1 to 5 equivalents, preferably 3 to 4 equivalents.

Preparation of compounds of formula 5

In one embodiment, the compound of Formula 5 is prepared by subjecting the compound of Formula 7 to an amide reaction with the compound of Formula 6.

In Formula 6, PG is an ester protecting group. Ester protection reactions are well established. Known ester protecting groups (PG) include, but are not limited to, C1-C10 alkyl such as methyl, ethyl, t-butyl, allyl, 1,1-dimethylallyl, and benzyl. , 4-methoxybenzyl, phenyl, silyl, 2-trimethylsilyl ethyl, 2-(Trimethylsilyl)ethoxymethyl ), diphenylmethyl, or oxazoline.

Preparation of compounds of formula 3

In one embodiment, the compound of Formula 3 is prepared by removing the ester protecting group (PG) from the compound of Formula 5. In the field of organic synthesis, deprotection of esters is well established (C.J.Salomon et al. ChemInform Vol.49, No.18, 3691-3734, 1993). Deprotection is not limited but can be carried out under basic conditions such as sodium hydroxide or potassium hydroxide.

Preparation of compounds of formula 2

In one embodiment, the compound of Formula 2 is prepared by performing an amide reaction between the compound of Formula 4 and the compound of Formula 3.

The method described in the preparation of Chemical Formula 5 may be used for the amide reaction.

Preparation of compounds of formula 1

In one embodiment, the compound of Formula 2 is reduced to prepare the compound of Formula 1.

For the reduction reaction of the nitro group, the method described in the preparation of Chemical Formula 7 can be used.

The above-described amide reaction and reduction reaction are known reactions, and reaction temperature, reaction time, filtration, concentration, solvent removal, separation, purification, extraction, drying, etc. can be performed by using or modifying known methods at the level of those skilled in the art of the present invention. So it can be used appropriately.

Hereinafter, the method for producing the amide pentamer according to the present invention will be described in more detail through examples. However, this is not intended to limit the invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the invention.

Scheme 2 below shows the overall process of the following examples.

[Scheme 2]

Example 1: N1,N4 - bis(4'-amino-2,2'-bis ( trifluoromethyl )-[1,1'-biphenyl]-4-yl) terephthalamide Synthesis of (Formula 4a) Synthesis of 4'-nitro-2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-amine (Formula 7a)

a) 4,4'- dinitro -2,2'- bis ( trifluoromethyl )-1,1'-biphenyl (Formula 8a) synthesis

Add 500ml of DMF, 270g (1mol) of 1-bromo-4-nitro-2-(trifluoromethyl)benzene (Formula 9a), and 189g (3mol) of copper powder (Cu powder) to a 3L round bottom flask and reflux for 3 hours. When the reaction is completed, the solid is removed by filtration, and the filtrate is concentrated in vacuum. Add 1000ml of ethylacetate (EA) to the residue and dissolve it, then add 10g of acidic activated carbon and stir for 30 minutes. After filtering on Celite and concentrating the filtrate in vacuum, add 800ml of methanol (MeOH) to the residue and reflux for 1 hour. The reaction solution was cooled to room temperature, filtered, and the obtained solid was dried under vacuum at 50°C to obtain 170 g of a pale yellow solid compound (yield 89.5%).

¹ H NMR (400 MHz, DMSO, δ): 7.83 (2H), 8.63 (4H), ppm

b) 4'-nitro-2,2'- bis ( trifluoromethyl )-[1,1'-biphenyl]-4-amine (Formula 7a) synthesis

Add 150 g (0.395 mol) of 4,4'-dinitro-2,2'-bis(trifluoromethyl)-1,1'-biphenyl (Formula 7a) and 1500 ml of MeOH synthesized in the above step to a 3L 3-neck round bottom flask and reflux. Stir to completely dissolve. Put the NaSH aqueous solution (1.3 mol) prepared in advance into a dropping funnel, attach it to the reactor, reflux the reaction solution, and add it dropwise over 1 hour. When the dropwise addition is completed, the reaction solution is refluxed for 8 hours. The reaction solution is cooled to room temperature, concentrated under vacuum, and the solvent is distilled off. Add 800ml of EA and 800ml of purified water to the residue, then transfer to a separatory funnel to separate the layers. The water layer is removed, and 10 g of anhydrous magnesium sulfate and neutral activated carbon are added to the organic layer. The reaction solution was stirred for 30 minutes, filtered over Celite, and the filtrate was concentrated under vacuum. Heptane 800ml was added to the residue and refluxed for 1 hour. The reaction solution was cooled to room temperature, filtered, and the obtained solid was dried under vacuum at 50°C to obtain 124 g of a pale yellow solid compound (yield 90%).

¹ H NMR (400 MHz, DMSO, δ): 5.84 (2H), 6.83 (1H), 6.99 (2H), 7.65 (1H), 8.51 (2H), ppm

Example 2: 4 -((4'-nitro-2,2'- bis ( trifluoromethyl )-[1,1'-biphenyl]-4-yl)carbamoyl)benzoic acid (Formula 3a) synthesis

a) Methyl 4-((4'-nitro-2,2'- bis ( trifluoromethyl )-[1,1'-biphenyl]-4-yl)carbamoyl)benzoate (Formula 5a) Synthesis

50.0 g of methyl 4-(chlorocarbonyl)benzoate (Formula 6a) and 88.2 g of 4'-nitro-2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-amine (Formula 7a) were added to the reactor. Add 500 ml of THF and stir to dissolve, add 33.1 g of TEA, and stir at 30°C for 10 hours to terminate the reaction. The reaction solution was removed by vacuum concentration, 300 ml of purified water and 500 ml of EA were added, stirred for 30 minutes, and left to stand to separate the layers. MgSO ₄ was added to the organic layer, stirred for 1 hour, filtered, and the filtrate was concentrated under vacuum and purified by silica gel column to obtain 120.6 g of solid compound (yield: 93.5%).

b) 4-((4'-nitro-2,2'- bis ( trifluoromethyl )-[1,1'-biphenyl]-4-yl)carbamoyl)benzoic acid (Formula 3a) synthesis

100.0 g of methyl 4-((4'-nitro-2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-yl)carbamoyl)benzoate (Formula 5a), 15.6 g of NaOH, and THF were added to the reactor. Add 300ml, 300ml of methanol, and 400ml of purified water and reflux and stir for 4 hours to terminate the reaction. The reaction solution is removed by vacuum concentration, 500 ml of purified water is added, stirred, 3N HCl solution is added dropwise to adjust the pH to 1, and the mixture is stirred and aged for 5 hours. The precipitated solid was filtered and dried under vacuum at 40°C for 12 hours to obtain 87.3 g of solid compound (yield: 89.8%).

Example 3: Amides with nitro groups pentamer Synthesis of (Formula 2a)

34.2 g of 4-((4'-nitro-2,2'-bis(trifluoromethyl)-[1,1'-biphenyl]-4-yl)carbamoyl)benzoic acid (Formula 3a) and 600 ml of THF were added to the reactor. , 12.6 g of SOCl ₂ was added dropwise, refluxed and stirred for 10 hours, then concentrated under vacuum to remove the solvent. Then, 500 ml of THF was added and stirred to dissolve. 10.0 g of TFDB (Monomer) and 11.1 g of TEA were added and stirred at 30°C for 12 hours. This terminates the reaction. After filtering the reaction solution to remove by-products, the filtrate was concentrated under vacuum, 350 ml of MC and 200 ml of purified water were added, stirred for 30 minutes, and left to stand to separate the layers. MgSO ₄ was added to the organic layer, stirred for 1 hour, filtered, and the filtrate was concentrated under vacuum and purified by silica gel column to obtain 34.2 g of solid (yield: 85.4%).

Example 4: Amides pentamer Synthesis of (Formula 1a)

30.0 g of the pentamer having a nitro group (Formula 2a) and 1000 ml of THF were added to the pressure reactor, 1 g of 10% Pd/C was added, and the reaction was terminated by stirring for 24 hours with a hydrogen pressure of 5 bar. The reaction solution was filtered to remove Pd/C, concentrated under vacuum, and purified by column to obtain 25.8 g of solid compound (yield: 90.2%).

Claims (13)

delete delete delete delete delete An amide pentamer, represented by formula 1a below.
[Formula 1a]

delete delete delete delete An intermediate of the amide pentamer of claim 6, represented by the following formula (2a).
[Formula 2a]

delete An intermediate of the amide pentamer of claim 6, represented by the following formula (3a').
[Formula 3a']

(In the above formula, X is halogen or hydroxy.)