JP2011225765A - METHOD FOR PRODUCING POLYBENZAMIDE-b-POLYSTYRENE BLOCK COPOLYMER - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polybenzamide-b-polystyrene block copolymer by which an object can be obtained by a short step with simple operation while being hardly influenced by steric hindrance.SOLUTION: Chain polycondensation of a compound (2) (wherein Rdenotes an 8-12C alkyl group or a benzyl group which may have a substituent and Rdenotes 1-10C alkyl group) is carried out in the presence of a base by using a compound (1) (wherein R denotes a 1-10C alkyl group and R' denotes a protective group of a hydroxyl group) as an initiator to obtain a polybenzamide derivative (A). Successively a product obtained by deprotection of the protective group is brought into reaction with an acid halide to obtain a polybenzamide derivative (B). Atom transfer radical polymerization of styrene is carried out in the presence of a metal catalyst by using the polybenzamide derivative (B) as a microinitiator to produce the polybenzamide-b-polystyrene block copolymer.

Description

  The present invention relates to a method for producing a polybenzamide-b-polystyrene block copolymer, and more specifically, a method for producing a polybenzamide-b-polystyrene block copolymer, which combines chain polycondensation and atom transfer radical polymerization. About.

  A rod-coil block copolymer in which one component is a rigid straight chain is a high molecular compound that has attracted much attention in recent years because it exhibits an interesting self-organization behavior in a solution state or a solid state.

The present inventor has already reported that rod-shaped polybenzamide having a narrow molecular weight distribution can be obtained by using a specific chain polycondensation reaction (see, for example, Patent Document 1 and Non-Patent Document 1). .
This polybenzamide can be led to a rod-coil block copolymer by a coupling reaction with another polymer utilizing the telechelic structure, a further polymerization reaction, or the like.

For example, the present inventor has reported that rod-coiled polystyrene-b-polybenzamide can be obtained by combining the above-described chain polycondensation reaction with reversible addition-fragmentation chain transfer (RAFT) polymerization. (For example, refer nonpatent literature 2).
In addition, the present inventor reports that rod-coiled polystyrene-b-polybenzamide can be obtained by performing the above-mentioned chain polycondensation reaction in the presence of a polystyrene macroinitiator obtained by living anion polymerization. (See, for example, Non-Patent Document 3).

However, the method of Non-Patent Document 3 has a problem that a high molecular weight polystyrene macroinitiator becomes a steric hindrance and inhibits the chain polycondensation reaction, and as a result, self-condensation tends to occur.
On the other hand, in the method of Non-Patent Document 2, although the problem of steric hindrance can be avoided because the chain polycondensation reaction is first performed, there is a problem that the synthesis route is very long and complicated operation is required.

JP 2005-314478 A

J. et al. Am. Chem. Soc. , 127 (29) 10172-10173 (2005) Macromol. Rapid Commun. , 30 (16) 1413-1418 (2009) J. et al. Polym. Sci. Part A: Polym. Chem. , 45 (14) 3129-3133 (2007)

  The present invention has been made in view of such circumstances, and is a method for producing a polybenzamide-b-polystyrene block copolymer that is less susceptible to steric hindrance and that provides a target product in a short process and simple operation. The purpose is to provide.

  As a result of intensive studies to achieve the above object, the present inventor made polybenzamide obtained by a chain polycondensation reaction as a macroinitiator, and polymerized styrene by an atom transfer radical polymerization reaction. The inventors have found that a polybenzamide-b-polystyrene block copolymer having a narrow molecular weight and a narrow molecular weight distribution can be efficiently obtained, thereby completing the present invention.

（式中、Ｒは、炭素数１〜１０のアルキル基を、Ｒ′は、水酸基の保護基を示す。）
で示される化合物をイニシエータとし、塩基の存在下、式（２）

（式中、Ｒ¹は、炭素数８〜１２のアルキル基または置換基を有していてもよいベンジル基を、Ｒ²は、炭素数１〜１０のアルキル基を示す。）
で示される化合物を連鎖重縮合させて式（３）

（式中、Ｒ′、Ｒ¹およびＲ²は前記と同じ。ｎは２以上の整数を示す。）
で示されるポリベンズアミド誘導体（Ａ）を得、続いて、前記保護基Ｒ′を脱保護して得られた生成物を、式（４）

（式中、Ｘ¹およびＸ²は、互いに独立して、ハロゲン原子を表す。）
で示される酸ハロゲン化物と反応させて、式（５）

（式中、Ｒ¹、Ｒ²、Ｘ¹およびｎは前記と同じ。）
で示されるポリベンズアミド誘導体（Ｂ）を得、このポリベンズアミド誘導体（Ｂ）をマクロイニシエータとし、金属触媒の存在下、スチレンを原子移動ラジカル重合させることを特徴とする、式（６）

（式中、Ｒ¹、Ｒ²、およびｎは前記と同じ。ｍは、２以上の整数を示す。）
で示されるポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、
２． 式（５）

（式中、Ｒ¹、Ｒ²、Ｘ¹およびｎは前記と同じ。）
で示されるポリベンズアミド誘導体（Ｂ）をマクロイニシエータとし、金属触媒の存在下、スチレンを原子移動ラジカル重合させることを特徴とする、式（６）

（式中、Ｒ¹、Ｒ²、およびｎは前記と同じ。ｍは、２以上の整数を示す。）
で示されるポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、
３． 前記Ｒ²が、メチル基またはエチル基である１または２のポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、
４． 前記Ｘ¹が、臭素原子である１〜３のいずれかのポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、
５． 前記金属触媒が、銅触媒である１〜４のいずれかのポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、
６． 前記式（２）で示される化合物が、式（２ａ）または（２ｂ）で示される１のポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法、

（式中、Ｒ¹およびＲ²は前記と同じ。）
７． 前記Ｒ′が、トリアルキルシリル基である１のポリベンズアミド−ｂ−ポリスチレンブロック共重合体の製造方法
を提供する。 That is, the present invention
1. Formula (1)

(In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and R ′ represents a hydroxyl-protecting group.)
And a compound represented by formula (2) in the presence of a base.

(In the formula, R ¹ represents an alkyl group having 8 to 12 carbon atoms or a benzyl group optionally having a substituent, and R ² represents an alkyl group having 1 to 10 carbon atoms.)
A compound represented by formula (3) is subjected to chain polycondensation.

(In the formula, R ′, R ¹ and R ² are the same as described above. N represents an integer of 2 or more.)
A polybenzamide derivative (A) represented by formula (4) is obtained, and then the product obtained by deprotecting the protecting group R ′ is represented by the formula (4)

(In the formula, X ¹ and X ² each independently represent a halogen atom.)
Is reacted with an acid halide represented by the formula (5)

(Wherein R ¹ , R ² , X ¹ and n are the same as above)
A polybenzamide derivative (B) represented by formula (6) is obtained, and the polybenzamide derivative (B) is used as a macroinitiator, and styrene is atom-transferred radically polymerized in the presence of a metal catalyst.

(In the formula, R ¹ , R ² and n are the same as described above. M represents an integer of 2 or more.)
A process for producing a polybenzamide-b-polystyrene block copolymer represented by:
2. Formula (5)

(Wherein R ¹ , R ² , X ¹ and n are the same as above)
A polybenzamide derivative (B) represented by the formula (6) is used as a macroinitiator, and styrene is atom transfer radical polymerized in the presence of a metal catalyst.

(In the formula, R ¹ , R ² and n are the same as described above. M represents an integer of 2 or more.)
A process for producing a polybenzamide-b-polystyrene block copolymer represented by:
3. A process for producing a 1 or 2 polybenzamide-b-polystyrene block copolymer, wherein R ² is a methyl group or an ethyl group;
4). The method for producing a polybenzamide-b-polystyrene block copolymer according to any one of 1 to 3, wherein X ¹ is a bromine atom,
5). The method for producing a polybenzamide-b-polystyrene block copolymer according to any one of 1 to 4, wherein the metal catalyst is a copper catalyst,
6). The method for producing a polybenzamide-b-polystyrene block copolymer of 1 represented by the formula (2a) or (2b), wherein the compound represented by the formula (2) is:

(In the formula, R ¹ and R ² are the same as above.)
7). Provided is a method for producing a polybenzamide-b-polystyrene block copolymer, wherein R ′ is a trialkylsilyl group.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the polybenzamide-b-polystyrene block copolymer which is hard to receive to the influence of a steric hindrance and can obtain a target object in a short process can be provided.

In the polymerization reaction of Example 5-8 is a graph showing the relationship between the reaction time and ln (M ₀ / M). It is a graph which shows the relationship between Mn, Mw / Mn, and the conversion rate in the polymerization reaction of Examples 5-8. FIG. 10 is a graph showing the change over time of the GPC chart in the reaction of Example 5. FIG. 10 is a graph showing the change over time of the GPC chart in the reaction of Example 9. In a reference example, it is a figure which shows the < ¹ > H-NMR spectrum before the addition of trifluoroacetic acid (a), 1 day after the addition (b), 4 days after the addition (c). In a reference example, it is a figure which shows the FT-IR spectrum before the addition of trifluoroacetic acid (a), 1 day after the addition (b), and 4 days after the addition (c).

Hereinafter, the present invention will be described in more detail.
The method for producing a polybenzamide-b-polystyrene block copolymer according to the present invention comprises a series of steps shown in the following scheme.

First, the substituents in the above formulas will be described.
In the above formulas, R and R ² each have an alkyl group having 1 to 10 carbon atoms, R ′ has a protecting group for a hydroxyl group, and R ¹ has an alkyl group having 8 to 12 carbon atoms or a substituent. In the benzyl group, X ¹ and X ² each independently represent a halogen atom, and n and m each represents an integer of 2 or more.

Specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, 1-methyl-n-butyl group, 2-methyl-n-butyl group, 3-methyl-n-butyl group, 1,1-dimethyl-n-propyl group, 1,2-dimethyl-n -Propyl group, 2,2-dimethyl-n-propyl group, 1-ethyl-n-propyl group, cyclopentyl group, n-hexyl group, 1-methyl-n-pentyl group, 2-methyl-n-pentyl group, 3-methyl-n-pentyl group, 4-methyl-n-pentyl group, 1,1-dimethyl-n-butyl group, 1,2-dimethyl-n-butyl group, 1,3-dimethyl-n-butyl group 2,2-dimethyl-n-butyl group 2,3-dimethyl-n-butyl group, 3,3-dimethyl-n-butyl group, 1-ethyl-n-butyl group, 2-ethyl-n-butyl group, 1,1,2-trimethyl-n- Propyl group, 1,2,2-trimethyl-n-propyl group, 1-ethyl-1-methyl-n-propyl group, 1-ethyl-2-methyl-n-propyl group, cyclohexyl group, n-heptyl group, An n-octyl group, an n-nonyl group, an n-decyl group, etc. are mentioned. Among these, as R and R ² , a methyl group and an ethyl group are preferable.

Examples of the alkyl group having 8 to 12 carbon atoms include an n-undecyl group and an n-dodecyl group in addition to the alkyl groups having 8 to 10 carbon atoms exemplified above.
Specific examples of the benzyl group which may have a substituent include a benzyl group; 4-methoxybenzyl group, 4-ethoxybenzyl group, 4-n-propoxybenzyl group, 4-i-propoxybenzyl group, 4- n-butoxybenzyl group, 4-t-butoxybenzyl group, 4-n-pentoxybenzyl group, 4-n-hexoxybenzyl group, 4-n-heptoxybenzyl group, 4-n-octoxybenzyl group, etc. 4-alkoxybenzyl group and the like. Among these, as R ¹ , an n-octyl group and a 4-alkoxybenzyl group are preferable, and as the 4-alkoxybenzyl group, a 4-octoxybenzyl group is more preferable.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. X ¹ and X ² are preferably a chlorine atom, a bromine atom, and an iodine atom, and more preferably a bromine atom.
m and n are integers of 2 or more, but an integer of 2 to 100 is preferable.

The hydroxyl-protecting group is not particularly limited as long as it is used as a hydroxyl-protecting group in a general organic synthesis reaction. For example, an acyl group having 1 to 7 carbon atoms (formyl, acetyl, fluoroacetyl) , Difluoroacetyl, trifluoroacetyl, chloroacetyl, dichloroacetyl, trichloroacetyl, propionyl, pivaloyl, tigloyl, etc.), arylcarbonyl groups (benzoyl, benzoylformyl, benzoylpropionyl, phenylpropionyl, etc.), C1-C4 alkoxycarbonyl Groups (methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl, i-propoxycarbonyl, n-butoxycarbonyl, i-butoxycarbonyl, t-butoxycarbonyl, t-amyloxycarbonyl Vinyloxycarbonyl, allyloxycarbonyl, 2- (trimethylsilyl) ethoxycarbonyl, 2,2,2-trichloroethoxycarbonyl, etc.), aryloxycarbonyl groups (benzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl) Etc.), C1-C4 alkylaminocarbonyl groups (such as methylcarbamoyl, ethylcarbamoyl, n-propylcarbamoyl), arylaminocarbonyl groups (such as phenylcarbamoyl), trialkylsilyl groups (trimethylsilyl, triethylsilyl, triisopropylsilyl) Diethylisopropylsilyl, dimethylisopropylsilyl, di-t-butylmethylsilyl, isopropyldimethylsilyl, t-butyldimethylsilyl, Such as hexyl dimethyl silyl), alkyldiarylsilyl groups (e.g., diphenylmethyl silyl, t- butyl diphenyl silyl, t- butyl dimethoxyphenylsilyl etc.), etc. triarylsilyl groups (such as triphenylsilyl) are exemplified.
Among these, R ′ is preferably a trialkylsilyl group, an alkyldiarylsilyl group, or a triarylsilyl group, more preferably a trialkylsilyl group, and most preferably a t-butyldimethylsilyl group.

Next, the manufacturing method of the polybenzamide-b-polystyrene block copolymer which concerns on this invention is demonstrated.
[1] Step 1: Production of polybenzamide derivative (A) represented by formula (3) Step 1 comprises aminobenzoic acid represented by formula (2) using a benzoic acid derivative represented by formula (1) as an initiator. This is a step of producing a polybenzamide derivative (A) by chain polycondensation of the derivative, and basically the reaction reported in Patent Document 1 and Non-Patent Document 1 described above.
In this case, the amount of the compound (initiator) represented by the formula (1) is preferably about 0.01 to 0.5 mol with respect to 1 mol of the compound represented by the formula (2).

The base used in this reaction is not particularly limited, but a strong base with low nucleophilicity is preferable, for example, t-butoxy potassium; lithium diisopropylamide (LDA), lithium hexamethyldisilazide, potassium Metal amides such as hexamethyldisilazide, sodium hexamethyldisilazide, lithium 2,2,6,6-tetramethylpiperidide are preferred, and lithium hexamethyldisilazide is most suitable.
The usage-amount of a base can be about 0.1-3 mol with respect to 1 mol of compounds shown by Formula (2) which is a polymerization substrate.

The solvent used in this reaction is arbitrary as long as the base to be used is dissolved and does not interfere with the polymerization reaction. For example, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; Ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, tetrahydrofuran, 1,4-dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, anisole; chloroform, dichloromethane, dichloroethane, tetrachloride Examples thereof include halogenated hydrocarbons such as carbon, ethers are preferable, and tetrahydrofuran is particularly preferable.
The polycondensation reaction temperature is preferably 10 ° C. or lower, more preferably 0 ° C. or lower, even more preferably −5 ° C. or lower, and most preferably about −10 ° C.

[2] Step 2: Production of polybenzamide derivative (B) represented by formula (5) Step 2 includes a deprotection product (hydroxyl thereof) obtained by deprotecting the polybenzamide derivative (A) obtained in Step 1. This is a step of reacting an acid halide represented by formula (4) (acylation) to produce a polybenzamide derivative (B) that becomes an initiator (macroinitiator) of the subsequent atom transfer radical polymerization reaction.
As the deprotection condition, a conventionally known method may be appropriately employed depending on the protecting group to be used. For example, in the case of a silyl ether protecting group such as a trialkylsilyl group, an acid such as hydrochloric acid, acetic acid, paratoluenesulfonic acid, hydrofluoric acid (HF), cesium fluoride (CsF), tetra-n-fluoride By using a reagent that generates a fluorine anion (fluoride ion) such as a fluorinated tetraalkylammonium salt such as butylammonium (TBAF), it can be easily removed. The usage-amount of these deprotection reagents is about 1-2 mol with respect to 1 mol of polybenzamide derivatives (A).
The reaction temperature is about −10 to 50 ° C., and the reaction time is about 0.1 to 5 hours.
In the deprotection reaction, a solvent that does not affect the reaction may be used, and examples of such a solvent include the same solvents as described above.

For the acylation reaction, known conditions generally used for the coupling reaction between an alcohol and an acid halide can be employed.
For example, a method of reacting a deprotected product with an acid halide represented by the formula (4) in the presence of a base in an organic solvent can be mentioned.
In this case, the usage-amount of the acid halide shown by Formula (4) can be about 1-20 mol with respect to 1 mol of deprotectors, and about 1-10 mol is suitable.
As the organic solvent, the organic solvents exemplified above can be used, but halogenated hydrocarbons such as dichloromethane are preferable.
As the base, a tertiary amine such as triethylamine is preferably used.
The reaction temperature is about -10 to 50 ° C.

[3] Step 3: Production of polybenzamide-b-polystyrene block copolymer represented by formula (6) Step 3 is atom transfer radical polymerization using the polybenzamide derivative (B) obtained in Step 2 as a macroinitiator. In this process, styrene is polymerized by a reaction to produce a target polybenzamide-b-polystyrene block copolymer.
Specifically, using a metal catalyst, styrene is radicalized based on an active species (polybenzamide derivative (B) radical) generated by radical cleavage of the halogen atom at the α-haloketone site of the macroinitiator in an organic solvent. This is a step of polymerization.
In this case, as the metal catalyst, a complex having copper, iron, nickel, ruthenium, rhodium, palladium, rhenium or the like as a central metal can be used, but a copper complex is preferable in consideration of cost. As the copper complex, a complex prepared from a copper (I) halide such as CuBr, CuI, or CuCl and an amine / imine multidentate ligand is preferably used.

Examples of amine / imine polydentate ligands include tris (2-dimethylaminoethyl) amine (Me ₆ TREN), tris [(2-pyridyl) methyl] amine (TPMA), N, N, N ′. , N ″, N ″ -pentamethyldiethylenetriamine (PMDETA), 2,2′-bipyridyl (Bpy) and the like, but considering the ease of progress of the polymerization reaction, Me ₆ TREN and TMPA are more preferable.
Examples of the organic solvent include the same ones as described above, but aromatic hydrocarbons such as toluene, xylene, and anisole are preferable.

In this reaction, the amount of styrene used varies depending on the length of the polystyrene chain, but it is preferably about 100 to 2000 mol with respect to 1 mol of the polybenzamide derivative (B).
Moreover, the usage-amount of a metal catalyst can be about 0.01-10 mol as a metal part with respect to 1 mol of polybenzamide derivatives (B), and about 0.1-2 mol is preferable.
What is necessary is just to set reaction temperature suitably from 0 degreeC to the boiling point of the solvent to be used, About 25-100 degreeC is preferable and about 40-100 degreeC is more preferable.
The reaction time varies depending on the catalyst used, but is usually about 1 to 120 hours.

In the production method described above, a chain polycondensation reaction that yields a polymer having a high molecular weight and a narrow molecular weight distribution is used in Step 1, and a polymer having a high molecular weight and a narrow molecular weight distribution is also obtained in Step 3. Since the atom transfer radical polymerization reaction is used, the target polybenzamide-b-polystyrene block copolymer also has a high molecular weight and a narrow molecular weight distribution.
For example, a highly controlled polybenzamide-b-polystyrene block copolymer having a number average molecular weight Mn (polystyrene equivalent value by GPC) of 7000 or more and a distribution (Mw / Mn) of about 1.30 or less is easy. Can get to.

EXAMPLES Hereinafter, although a synthesis example and an Example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. Each measuring device used in the examples is as follows. Styrene, triethylamine, and each solvent were purified by distillation before use.
[GC]
Device: GC-14B (manufactured by Shimadzu Corporation)
Column: OV-101 (manufactured by GL Sciences) 3m
Detector: FID
Internal standard: naphthalene (process 1), anisole (process 3)
The conversion during the polymerization was determined from the ratio between the area of the detection peak of naphthalene and anisole and the area of the monomer.
[ ¹ H-NMR]
Apparatus: JEOL ECA600 (600 MHz) (manufactured by JEOL Ltd.)
Measurement solvent: CDCl ₃ , DMF-d7
Reference materials: tetramethylsilane (TMS) (0.00 ppm), DMF (2.74 ppm)
[ ¹³ C-NMR]
Apparatus: JEOL ECA600 (600 MHz) (manufactured by JEOL Ltd.)
Measurement solvent: CDCl ₃ , DMSO-d6
Reference materials: CDCl ₃ (77.0 ppm), DMSO-d6 (39.5 ppm)
[FT-IR]
Apparatus: FT / IR-410 (manufactured by JASCO Corporation)
[GPC]
Apparatus: HLC-8200 (manufactured by Tosoh Corporation)
Column: 2 TSK-GEL Multipore HXL-M (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Solvent: Tetrahydrofuran 1 mL / min Detector: UV (254 nm), RI
Calibration curve: Standard polystyrene

（式中、ＴＢＳはｔ−ブチルジメチルシリル基を意味する） [Synthesis Example 1] Synthesis of Compound [1]

(In the formula, TBS means t-butyldimethylsilyl group)

In a 250 mL round bottom flask, 5.42 g (36 mmol) of t-butylchlorodimethylsilane, 2.45 g (36 mmol) of imidazole, and 50 mL of dry tetrahydrofuran (THF) were added and stirred. Into this mixture, 4.99 g (30 mmol) of methyl 4- (hydroxymethyl) benzoate dissolved in 20 mL of dry THF was gradually added dropwise at room temperature using a dropping funnel, and the mixture was stirred at 23 ° C. for 22 hours.
Thereafter, 50 mL of pure water was added to stop the reaction, and the mixture was extracted with 100 mL of methylene chloride. The organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and pure water, 20 g of magnesium sulfate was added, and the mixture was allowed to stand overnight and dried, and then filtered. The crude product obtained by distilling off the solvent with an evaporator was purified by silica gel column chromatography (hexane → methylene chloride) to obtain 7.54 g (yield 75%) of a colorless liquid compound [1].
¹ H-NMR (600 MHz, CDCl ₃ , δ, ppm): 8.02-7.98 (m, 2H), 7.40-7.36 (m, 2H), 4.78 (s, 2H) 3.89 (s, 3H), 0.94 (s, 9H), 0.10 (s, 6H).
¹³ C-NMR (150 MHz, DMSO-d ₆ , δ, ppm): 165.92, 146.64, 128.97, 128.08, 125.72, 63.67, 51.81, 25.60, 17.82, -5.54.

[Synthesis Example 2] Synthesis of Compound [2a]

Ethyl 4-aminobenzoate 8.23 g (50 mmol), octanal 7.08 mL (45.3 mmol) and THF 100 mL were mixed. To this mixture, 2.9 mL (50 mmol) of acetic acid was dropped with a pipette over 5 minutes, and the mixture was stirred at 23 ° C. for 10 minutes. Immediately thereafter, 16.3 g (77 mmol) of sodium triacetoxyborohydride was added. After the mixture was stirred at room temperature for 24 hours, a saturated aqueous sodium hydrogen carbonate solution was added to the reaction solution to adjust the solution slightly basic (pH = 8), and the mixture was extracted with 100 mL of ethyl acetate. The organic layer was washed with 100 g of saturated brine, 20 g of anhydrous magnesium sulfate was added, and the mixture was left to dry overnight, and then filtered. The solvent was distilled off under reduced pressure, and the residue was recrystallized from methanol to obtain 7.799 g (yield 62%) of colorless crystalline compound [2a].
¹ H-NMR (600 MHz, CDCl ₃ ) δ (ppm) = 7.87-7.84 (m, 2H), 6.54-6.52 (m, 2H), 4.31 (q, J = 7.21 Hz, 2H), 4.05 (s, 1H), 3.15 (t, J = 7.21 Hz, 2H), 1.65-1.60 (p, J = 7.21 and 7) .56 Hz, 2H), 1.42-1.26 (m, 13H), 0.88 (t, J = 6.87 Hz, 3H).
¹³ C-NMR (150 MHz, CDCl ₃ ) δ (ppm) = 166.88, 152.03, 131.46, 118.35, 111.24, 60.11, 43.38, 31.78, 29. 33, 29.21, 27.06, 22.63, 14.45, 14.08.

[1] Synthesis of polybenzamide derivative by chain polycondensation reaction [Example 1] Synthesis of polybenzamide derivative [3a]

To a 10 mL flask with a three-way cock that was dried and filled with argon, 0.5 mL of dry THF was added in an argon atmosphere and stirred at −10 ° C. for 10 minutes, and then a 1.0 M THF solution of lithium hexamethyldisilazide (LiHMDS) 0.5 mL (0.5 mmol) was added, cooled to −10 ° C., and stirred for 10 minutes. Among them, compound [1] obtained in Synthesis Example 1 (Initiator: I) 14 mg (0.05 mmol), compound [2a] obtained in Synthesis Example 2 (monomer: M) 0.132 g (0.5 mmol) ) ([M] ₀ / [I] ₀ = 10) and 64 mg (0.50 mmol) of naphthalene (internal standard) dissolved in 1 mL of dry THF were cooled to −10 ° C. and added all at once. In order to confirm the conversion rate of the reaction, a part of the reaction solution was taken out at regular intervals and the polymerization reaction was followed by GC. After confirming that the reaction was complete, a saturated aqueous ammonium chloride solution was added to stop the reaction. After diluting with 10 mL of methylene chloride, the organic layer was washed with pure water, added with 1 g of anhydrous magnesium sulfate and allowed to stand overnight to dry, and then filtered. Concentration under reduced pressure gave the crude product as a yellow oil. This crude product was dissolved in 1 mL of methylene chloride, precipitated twice in 10 mL of a mixed solvent of methanol / water (9/1, v / v), and polybenzamide derivative [3a] (hereinafter referred to as PpBzAm) as a yellow viscous product. -OTBS1 in some cases) was obtained (Mn = 3010, Mw / Mn = 1.07, yield 71.5%).

[Example 2] Synthesis of polybenzamide derivative [3b]

The compound [2a] was changed to the compound [2b], and a polybenzamide derivative was obtained in the same manner as in Example 1 except that the reaction was performed by adding 0.105 g (2.5 mmol) of lithium chloride together with a THF solution of LiHMDS. [3b] (hereinafter also referred to as PmOOBBzAm-OTBS) was obtained (Mn = 4520, Mw / Mn = 1.09).
In addition, compound [2b] Polym. Sci. Part A: Polym. Chem. 2006, 44, 4990-5003.
A summary of Examples 1-2 above is shown in Table 1.

[2] Synthesis of Macroinitiator [Example 3] Synthesis of polybenzamide derivative [4a]

(1) Deprotection 0.51 g (0.17 mmol) of the polybenzamide derivative [3a] (PpBzAm-OTBS1) obtained in Example 1 was dissolved in 3 mL of dry THF, and a 1.0 M THF solution of tetrabutylammonium fluoride (TBAF). 0.20 mL (0.20 mmol) was added at room temperature under an argon atmosphere. The resulting mixture was stirred at 23 ° C. for 2 hours. After confirming that the reaction proceeded quantitatively by ¹ H-NMR analysis, 5 mL of pure water was added to stop the reaction, and the mixture was extracted with 10 mL of methylene chloride. The organic layer was washed with pure water, 1 g of anhydrous magnesium sulfate was added, and the mixture was left to dry overnight, and then filtered. Concentration under reduced pressure gave 0.48 g (yield 94%) of the deprotected product (PpBzAm-OH1) as a yellow viscous product.

(2) Acylation In a 50 mL one-necked round bottom flask dried and filled with nitrogen, 0.48 g (0.16 mmol) of the deprotected product (PpBzAm-OH) obtained above and 0.22 mL (1. 6 mmol) was mixed with 10 mL of methylene chloride, stirred at 23 ° C. for 15 minutes, and then cooled to 0 ° C. Thereafter, a solution of 0.20 mL (1.6 mmol) of 2-bromoisobutyryl bromide in 5 mL of dry methylene chloride was added dropwise, and stirring was continued at 23 ° C. for 23 hours under a nitrogen atmosphere. After confirming that the reaction proceeded quantitatively by ¹ H-NMR analysis, 5 mL of pure water was added to stop the reaction, and the mixture was extracted with 10 mL of methylene chloride. The organic layer was washed with a saturated aqueous sodium hydrogen carbonate solution and pure water, and the organic layer was separated. After adding 1 g of magnesium sulfate to the organic layer and leaving it to stand overnight, it was filtered. The crude product obtained by distilling off the solvent under reduced pressure was dissolved in 2 mL of methylene chloride, and precipitated twice in 20 mL of a mixed solvent of methanol / water (9/1, v / v) to give a polybenzamide derivative as a yellow viscous oil. [0a] 0.40 g (yield 83%) of (PpBzAm-Br1) was obtained.

[Example 4] Synthesis of polybenzamide derivative [4b]

  A polybenzamide derivative [4b] (PmOOBBzAm-Br) was obtained in the same manner as in Example 3, except that the polybenzamide derivative [3b] (PmOOBBzAm-OTBS) was used instead of the polybenzamide derivative [3a] ( Yield 81%).

[3] Synthesis of polybenzamide-b-polystyrene block copolymer by atom transfer radical polymerization In the following, molecular weight and molecular weight distribution were measured by GPC, and conversion was measured by GC.
[Example 5] Synthesis of polybenzamide-b-polystyrene block copolymer [5a]

A 25 mL Schlenk flask was charged with styrene, Me ₆ TREN, polybenzamide derivative [4a] (PpBzAm-Br1), and anisole. The mixture was cooled to −78 ° C. to solidify, deoxidized by repeating freeze-pump-thaw three times, and filled with nitrogen gas. Subsequently, CuBr was added to the frozen solution. The flask was sealed, vacuum degassed, and freeze degassing was repeated twice. After taking out an initial sample with a syringe, the flask was put into an oil bath preheated to 70 ° C. to initiate polymerization. In order to confirm the conversion rate of the reaction, a part of the reaction solution was taken out at regular intervals and the polymerization reaction was followed by GC (internal standard: anisole). After confirming that the reaction was completed, the flask was put into an ice bath and exposed to air to stop the polymerization reaction. The obtained mixture was diluted with THF, the copper catalyst was removed through a column packed with neutral aluminum oxide (alumina), precipitated in methanol, filtered and dried in vacuo, and the target product, polybenzamide-b-polystyrene. A block copolymer [5a] was obtained (Mn = 23400 g / mol, Mw / Mn = 1.24, conversion = 40%).
In the above reaction, the use ratio of each reagent is styrene / polybenzamide derivative [4] (PpBzAm-Br) / CuBr / Me ₆ TREN = 600/1/1/1 (molar ratio), and 13 volume% anisole. It was carried out in solution (vs. styrene: 7.56M).

[Examples 6 to 8] Synthesis of polybenzamide-b-polystyrene block copolymer [5a] Same as Example 5 except that Me ₆ TREN, which is a ligand for Cu, was changed to TPMA, PMDETA, and Bpy, respectively. Thus, a polybenzamide-b-polystyrene block copolymer [5a] was synthesized. However, the amount of Bpy used was 2 mol.

[Example 9] Synthesis of polybenzamide-b-polystyrene block copolymer [5b]

A polybenzamide-b-polystyrene block copolymer [5b] was synthesized in the same manner as in Example 5 except that the polybenzamide derivative [4b] (PmOOBBzAm-Br) was used instead of the polybenzamide derivative [4a]. (Mn = 20000 g / mol, Mw / Mn = 1.37, conversion = 27%).
The results of Examples 5 to 9 are summarized in Table 2.

Regarding the polymerization reactions of Examples 5 to 9, the relationship between reaction time and ln (M ₀ / M) is shown in FIG. 1, and the relationship between Mn, Mw / Mn and conversion is shown in FIG. 1 and 2, Me ₆ TREN corresponds to Example 5, TPMA corresponds to Example 6, PMDETA corresponds to Example 7, and Bpy corresponds to Example 8.
Moreover, the GPC tracking result in the reaction of Example 5 is shown in FIG. 3, and the GPC tracking result in the reaction of Example 9 is shown in FIG. 4, respectively.
FIG. 1 shows the respective monomer consumption rates, which are found to be consistent with the conversion of styrene monomer in Table 2.
Further, as shown in FIG. 2, in principle, the monomer conversion rate and the theoretical molecular weight are almost the same in any system, so that it is assumed that styrene is polymerized from Br of polybenzamide as ideal.
Further, FIGS. 3 and 4 show changes in molecular weight with time. Since the molecular weight distribution of a general polymer increases as the molecular weight increases, the base of the mountain is widened, but it is understood that this is not seen in this system.

[Reference Example] Deprotection of polybenzamide-b-polystyrene block copolymer [5b]

A 10 mL flask equipped with a three-way cock was dried and filled with argon, and then charged with 32 mg of the polybenzamide-b-polystyrene block copolymer [5b] obtained in Example 9 and 1.5 mL of dry methylene chloride. After adding 1 mL of trifluoroacetic acid thereto, the mixture was stirred at room temperature for 1 day under an argon atmosphere in order to remove the octyloxybenzyl group. The solvent was distilled off under reduced pressure, and the resulting crude product was dissolved in 1 mL of methylene chloride, precipitated twice in 10 mL of hexane, and poly (N-H-metabenzamide) -b-polystyrene block copolymer of white powder. A coalescence was obtained (22 mg, 78% yield).
FIG. 5 shows ¹ H-NMR spectra before (a), 1 day after the addition of trifluoroacetic acid (b), and 4 days after the addition (c).
As shown in FIG. 5, it can be seen that one day after the addition, peaks derived from octyloxybenzyl groups located at 4.25 to 4.85 ppm and 3.35 to 3.45 ppm disappeared. As shown in the FT-IR spectrum of FIG. 6, it was confirmed that the ester and amide in the polymer main chain remained.
From this result, it was shown that selective hydrolysis was possible and that the ester bond in the main chain was excellent in stability.

Claims (7)

Formula (1)

(In the formula, R represents an alkyl group having 1 to 10 carbon atoms, and R ′ represents a hydroxyl-protecting group.)
And a compound represented by formula (2) in the presence of a base.

(In the formula, R ¹ represents an alkyl group having 8 to 12 carbon atoms or a benzyl group optionally having a substituent, and R ² represents an alkyl group having 1 to 10 carbon atoms.)
A compound represented by formula (3) is subjected to chain polycondensation.

(In the formula, R ′, R ¹ and R ² are the same as described above. N represents an integer of 2 or more.)
A polybenzamide derivative (A) represented by formula (4) is obtained, and then the product obtained by deprotecting the protecting group R ′ is represented by the formula (4)

(In the formula, X ¹ and X ² each independently represent a halogen atom.)
Is reacted with an acid halide represented by the formula (5)

(Wherein R ¹ , R ² , X ¹ and n are the same as above)
A polybenzamide derivative (B) represented by formula (6) is obtained, and the polybenzamide derivative (B) is used as a macroinitiator, and styrene is atom-transferred radically polymerized in the presence of a metal catalyst.

(In the formula, R ¹ , R ² and n are the same as described above. M represents an integer of 2 or more.)
The manufacturing method of the polybenzamide-b-polystyrene block copolymer shown by these. Formula (5)

(Wherein R ¹ , R ² , X ¹ and n are the same as above)
A polybenzamide derivative (B) represented by the formula (6) is used as a macroinitiator, and styrene is atom transfer radical polymerized in the presence of a metal catalyst.

(In the formula, R ¹ , R ² and n are the same as described above. M represents an integer of 2 or more.)
The manufacturing method of the polybenzamide-b-polystyrene block copolymer shown by these. The method for producing a polybenzamide-b-polystyrene block copolymer according to claim 1 or 2, wherein R ² is a methyl group or an ethyl group. Wherein X ¹ is, the production method of the poly benzamide -b- polystyrene block copolymer according to any one of claims 1 to 3 is a bromine atom.   The method for producing a polybenzamide-b-polystyrene block copolymer according to any one of claims 1 to 4, wherein the metal catalyst is a copper catalyst. The method for producing a polybenzamide-b-polystyrene block copolymer according to claim 1, wherein the compound represented by the formula (2) is represented by the formula (2a) or (2b).

(In the formula, R ¹ and R ² are the same as above.)   The method for producing a polybenzamide-b-polystyrene block copolymer according to claim 1, wherein R 'is a trialkylsilyl group.

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