JP6252032B2 - Benzodifuran derivatives and organic thin film transistors - Google Patents

Description

  The present invention relates to a novel benzodifuran derivative that can be developed into an electronic material such as an organic semiconductor material, and an organic thin film transistor using the same. Particularly, since it has excellent solubility in a solvent, it is easy to form an organic material for film formation. The present invention relates to a novel benzodifuran derivative that can be developed into a semiconductor solution and an organic thin film transistor using the same.

  Organic semiconductor devices typified by organic thin film transistors have been attracting attention in recent years because they have features not found in inorganic semiconductor devices such as energy saving, low cost, and flexibility. This organic semiconductor device is composed of several kinds of materials such as an organic semiconductor layer, a substrate, an insulating layer, and an electrode. Among them, the organic semiconductor layer responsible for charge carrier movement has a central role of the device. And since organic-semiconductor device performance is influenced by the carrier mobility of the organic-semiconductor material which comprises this organic-semiconductor layer, the appearance of the organic-semiconductor material which gives a high carrier mobility is desired.

In addition, as a method for producing the organic semiconductor layer, a method such as a vacuum deposition method in which an organic material is vaporized under a high temperature vacuum, a coating method in which an organic material is dissolved in an appropriate solvent, and a solution thereof is applied is generally used. Known. In the coating method, the coating can be performed using a printing technique without using a high temperature and high vacuum condition. Therefore, the coating method is an economically preferable process because it can greatly reduce the manufacturing cost of device fabrication by printing. Organic semiconductor materials used for such coating methods include low molecular weight and high molecular weight materials, but low molecular weight materials that can obtain carrier mobility exceeding 1.0 cm ² / Vs are preferred. preferable. Furthermore, it is preferable from the viewpoint of device fabrication process that it has a solubility of 1.0% by weight or more at room temperature and also has a heat resistance of 130 ° C. or more. However, there is currently no known low molecular weight organic semiconductor material that combines high carrier mobility, high solubility, and high heat resistance.

  Examples of the low molecular weight material include bis ((triisopropylsilyl) ethynyl) pentacene (see, for example, Non-Patent Document 1), dialkyl-substituted benzothienobenzothiophene (see, for example, Patent Document 1), and dialkyldithienobenzo. Dithiophene (see, for example, Patent Document 2) has been proposed.

Re-published patent WO2008 / 047896 (see, for example, the claims) Japanese translations of PCT publication No. 2011/526588 (see, for example, claims)

Journal of Polymer Science: Part B: Polymer Physics, 2006, 44, 3631-3641

However, bis {(triisopropylsilyl) ethynyl} pentacene described in Non-Patent Document 1 has a coating film mobility of 0.3 to 1 cm ² / Vs. It has been reported to drop to ² cm ² / Vs. Also, in the case of dialkyl-substituted benzothienobenzothiophene described in Patent Document 1, it has been reported that transistor operation is lost when heat-treated at 130 ° C. The dihexyl dithienobenzodithiophene proposed in Patent Document 2 shows a mobility of 0.112 cm ² / Vs by a drop cast method, but has a problem in solubility in a solvent at room temperature.

  Accordingly, a coating type organic semiconductor material having high carrier mobility, high heat resistance, and high solubility is desired, and the present invention aims to provide a novel organic semiconductor material that solves the conventional problems. To do.

  As a result of intensive studies to solve the above problems, the present inventors have found that an organic thin film transistor having high carrier mobility and high solubility and high heat resistance can be obtained by using a novel benzodifuran derivative. The present invention has been completed.

  That is, the present invention relates to a benzodifuran derivative represented by the following general formula (1) and an organic thin film transistor using the benzodifuran derivative.

(Wherein the substituents R ¹ and R ² are the same or different and are hydrogen, bromine, iodine, an alkyl group having 1 to 12 carbon atoms, an aryl group having 4 to 14 carbon atoms, an alkynyl group having 2 to 14 carbon atoms, A C2-C14 alkenyl group, and T ¹ and T ² are the same or different and represent sulfur and oxygen.)
The present invention is described in detail below.

The benzodifuran derivative of the present invention is a derivative represented by the above general formula (1), and the substituents R ¹ and R ² are the same or different and are hydrogen, bromine, iodine, an alkyl group having 1 to 12 carbon atoms, and 4 carbon atoms. -14 aryl group, alkynyl group having 2 to 14 carbon atoms, and alkenyl group having 2 to 14 carbon atoms, and T ¹ and T ² are the same or different and represent sulfur and oxygen.

Examples of the alkyl group having 1 to 12 carbon atoms in the substituents R ¹ and R ² include methyl group, ethyl group, n-propyl group, n-butyl group, isobutyl group, n-pentyl group, n-hexyl group, n- An alkyl group such as a heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-dodecyl group, a 2-ethylhexyl group, a cyclohexyl group, and a cyclooctyl group.

Examples of the aryl group having 4 to 14 carbon atoms in the substituents R ¹ and R ² include a 2-furyl group, a 5-fluoro-2-furyl group, a 5-methyl-2-furyl group, and a 5-ethyl-2-furyl group. , 5- (n-propyl) -2-furyl group, 5- (n-butyl) -2-furyl group, 5- (n-pentyl) -2-furyl group, 5- (n-hexyl) -2- Furyl group, 5- (n-octyl) -2-furyl group, 5- (2-ethylhexyl) -2-furyl group, 2-thienyl group, 5-fluoro-2-thienyl group, 5-methyl-2-thienyl group Group, 5-ethyl-2-thienyl group, 5- (n-propyl) -2-thienyl group, 5- (n-butyl) -2-thienyl group, 5- (n-pentyl) -2-thienyl group, 5- (n-hexyl) -2-thienyl group, 5- (n-octyl) -2-thienyl group Alkyl-substituted chalcogenophene groups such as 5- (2-ethylhexyl) -2-thienyl group, phenyl group, p-tolyl group, p- (n-hexyl) phenyl group, p- (n-octyl) phenyl group, p- ( And alkyl-substituted phenyl groups such as 2-ethylhexyl) phenyl group.

Examples of the alkynyl group having 2 to 14 carbon atoms in the substituents R ¹ and R ² include ethynyl group, n-propynyl group, n-butynyl group, n-pentynyl group, n-hexynyl group, n-heptynyl group, and n-octynyl group. Group, n-noninyl group, n-decynyl group, n-dodecynyl group, {5- (n-butyl) -2-furyl} ethynyl group, {5- (n-pentyl) -2-furyl} ethynyl group, { 5- (n-hexyl) -2-furyl} ethynyl group, {5- (n-heptyl) -2-furyl} ethynyl group, {5- (n-butyl) -2-thienyl} ethynyl group, {5- (N-pentyl) -2-thienyl} ethynyl group, {5- (n-hexyl) -2-thienyl} ethynyl group, {5- (n-heptyl) -2-thienyl} ethynyl group, {4- (n -Hexyl) phenyl} ethynyl group, etc. An alkynyl group.

Examples of the alkenyl group having 2 to 14 carbon atoms in the substituents R ¹ and R ² include an ethenyl group, an n-propenyl group, an n-butenyl group, an n-pentenyl group, an n-hexenyl group, an n-heptenyl group, and an n-octenyl group. Group, n-nonel group, n-decenyl group, n-dodecenyl group, 2- {5- (n-butyl) -2-furyl} ethenyl group, 2- {5- (n-pentyl) -2-furyl} Ethenyl group, 2- {5- (n-hexyl) -2-furyl} ethenyl group, 2- {5- (n-heptyl) -2-furyl} ethenyl group, 2- {5- (n-butyl)- 2-thienyl} ethenyl group, 2- {5- (n-pentyl) -2-thienyl} ethenyl group, 2- {5- (n-hexyl) -2-thienyl} ethenyl group, 2- {5- (n -Heptyl) -2-thienyl} ethenyl group, 2- {4- (n Hexyl) alkenyl group such as a phenyl} ethenyl group.

  Among them, an alkyl group having 1 to 6 carbon atoms and an aryl group having 4 to 12 carbon atoms are preferable because of particularly high heat resistance and high solubility, and an ethyl group, n-propyl group, n-butyl group, n- Pentyl group, n-hexyl group, 5-ethyl-2-furyl group, 5- (n-propyl) -2-furyl group, 5- (n-butyl) -2-furyl group, 5- (n-pentyl) 2-furyl group, 5- (n-hexyl) -2-furyl group, 5- (n-heptyl) -2-furyl group, 5- (n-octyl) -2-furyl group, 5- (n- Propyl) -2-thienyl group, 5- (n-butyl) -2-thienyl group, 5- (n-pentyl) -2-thienyl group, 5- (n-hexyl) -2-thienyl group, 5- ( n-heptyl) -2-thienyl group and 5- (n-octyl) -2-thienyl group are particularly preferable.

T ¹ and T ² are the same or different and represent sulfur and oxygen, preferably sulfur.

  Specific examples of the benzodifuran derivative of the present invention include the following.

  More preferred are diethyl dithienobenzodifuran, di-n-propyldithienobenzodifuran, di-n-pentyldithienobenzodifuran, di-n-hexyldithienobenzodifuran, di-n-heptyldifuran. Thienobenzodifuran, di-n-octyldithienobenzodifuran, bis (5-ethyl-2-furyl) dithienobenzodifuran, bis {5- (n-propyl) -2-furyl} dithienobenzodifuran Bis {5- (n-butyl) -2-furyl} dithienobenzodifuran, bis {5- (n-pentyl) -2-furyl} dithienobenzodifuran, bis {5- (n-hexyl) -2-furyl} dithienobenzodifuran, bis {5- (n-heptyl) -2-furyl} dithienobenzodifuran, bis {5- (n-octyl) -2-furyl Dithienobenzodifuran, bis (5-ethyl-2-thienyl) dithienobenzodifuran, bis {5- (n-propyl) -2-thienyl} dithienobenzodifuran, bis {5- (n-butyl) ) -2-thienyl} dithienobenzodifuran, bis {5- (n-pentyl) -2-thienyl} dithienobenzodifuran, bis {5- (n-hexyl) -2-thienyl} dithienobenzodi And furan, bis {5- (n-octyl) -2-thienyl} dithienobenzodifuran, and the like.

Among the benzodifuran derivatives of the present invention, a compound in which T ¹ and T ² are sulfur, that is, a dithienobenzodifuran derivative can be produced by any production method as long as the dithienobenzodifuran derivative can be produced. It is also possible to use. In the case of producing a dithienobenzodifuran derivative in which the substituents R ¹ and R ² are alkyl groups having 1 to 12 carbon atoms, dithienobenzodifuran is produced by a production method through the following steps (A1) to (E1). It is preferred to produce derivatives.

  (A1) step; 1,4 by palladium-catalyzed cross-coupling of 3-bromofuran-2-zinc derivative prepared from 2,3-dibromofuran and 1,4-dibromo-2,5-dihalobenzene in the presence of a palladium catalyst. A step of producing di (3-bromofuryl) -2,5-dihalobenzene.

  (B1) step; a step of synthesizing a bromohalomonocyclized product by a monomolecular cyclization reaction using 1,4-di (3-bromofuryl) -2,5-dihalobenzene obtained in step (A1) and sodium sulfide.

  Step (C1): A step of producing a diacyl derivative of a bromohalomonocyclized product by Friedel-Crafts acylation reaction of the bromohalomonocyclized product obtained in Step (B1) and an acyl chloride compound in the presence of aluminum chloride as a catalyst.

  (D1) Step; (C1) A step of subjecting the diacyl of the bromomonocyclized product obtained in Step (C1) to a reduction reaction to produce a dialkyl of bromohalomonocyclized product.

  (E1) Step; (D1) A dialkyl form of the bromohalomonocyclized product obtained in Step (D1) is subjected to a method of dilithiation with n-butyllithium / a second ring with bis (phenylsulfonyl) sulfide, and dithienobenzo A step of producing a gifuran derivative.

  A preferred more specific production method is shown in the following reaction scheme 1.

(Here, the substituent X ¹ represents fluorine and iodine, the substituent X ² represents fluorine and bromine, and the substituent R ³ represents hydrogen and an alkyl group having 1 to 11 carbon atoms.)
Here, the step (A1) is carried out by cross-coupling of a 3-bromofuran-2-zinc derivative and 1,4-dibromo-2,5-dihalobenzene in the presence of a palladium catalyst to produce 1,4-di (3-bromofuryl). This is a process for producing -2,5-dihalobenzene.

  The 3-bromofuran-2-zinc derivative is prepared by using, for example, an organometallic reagent such as isopropyl magnesium bromide, ethyl magnesium chloride, phenyl magnesium chloride, etc., replacing bromine at the 2-position of 2,3-dibromofuran with magnesium halide, and then zinc chloride. And can be prepared by exchanging metals. It is also possible to prepare a Grignard reagent of 2,3-dibromofuran using magnesium metal instead of the organometallic reagent. The conditions for preparing the 2,3-dibromofuran Grignard reagent are, for example, in a solvent such as tetrahydrofuran (hereinafter referred to as THF), diethyl ether, or N, N-dimethylformamide (hereinafter referred to as DMF). It can implement within the temperature range of -50-100 degreeC. A 3-bromofuran-2-zinc derivative can be prepared by reacting the Grignard reagent solution with zinc chloride. Zinc chloride may be used as it is, or it may be THF or diethyl ether solution. As temperature, it can implement within the range of -70 degreeC-30 degreeC.

  1,4-di (3-bromofuryl) -2,5-dihalobenzene is obtained by cross-coupling 3-bromofuran-2-zinc derivative and 1,4-dibromo-2,5-dihalobenzene in the presence of a palladium catalyst. Can be synthesized. Examples of the palladium catalyst at that time include tetrakis (triphenylphosphine) palladium, bis (triphenylphosphine) dichloropalladium and the like. The amount of the catalyst used is 1,4-dibromo-2,5-dihalobenzene 1 0.1-10 mol% is preferable with respect to mol, and 20-80 degreeC of reaction temperature is preferable.

  In the step (B1), 1,4-di (3-bromofuryl) -2,5-dihalobenzene is subjected to a monomolecular cyclization reaction with sodium sulfide in a solvent such as N-methylpyrrolidone (hereinafter referred to as NMP) or DMF. In a temperature range of 80 to 200 ° C. Sodium sulfide may be a hydrate. The amount of sodium sulfide used is preferably 0.9 to 1.5 equivalents per equivalent of 1,4-di (3-bromofuryl) -2,5-dihalobenzene.

  Step (C1) is a step of producing a diacyl derivative of bromohalomonocyclized product by Friedel-Crafts acylation reaction of bromohalomonocyclized product and acyl chloride compound in the presence of aluminum chloride as a catalyst.

  Examples of the acyl chloride compound include butanoyl chloride, pentanoyl chloride, hexanoyl chloride, heptanoyl chloride, octanoyl chloride and the like. The Friedel-Crafts acylation reaction can be performed in a solvent such as dichloromethane, 1,2-dichloroethane, toluene and the like at a temperature range of −80 to 40 ° C. The amount of aluminum chloride used is preferably 1.8 to 3.5 equivalents per equivalent of bromohalomonocyclized compound, and the amount of acyl chloride compound used is preferably 1.8 to 3.0 equivalents per equivalent of bromohalomonocyclized product. .

  Step (D1) is a step of producing a dialkyl body of a bromomonocyclized product by subjecting the diacyl body of the bromohalomonocyclic product to a reduction reaction.

  The reduction reaction of the diacyl derivative of bromohalomonocyclized product can be performed, for example, using hydrazine as a reducing agent in diethylene glycol, ethylene glycol or triethylene glycol in the presence of potassium hydroxide or sodium hydroxide at a temperature range of 80 to 250 ° C. it can. Further, for example, sodium borohydride / aluminum chloride can be used as a reducing agent, and the reaction can be performed in a solvent of diethyl ether, diisopropyl ether, methyl tertiary butyl ether or THF at a temperature range of −10 to 80 ° C. The amount of sodium borohydride used is preferably 1.8 to 8.0 equivalents per equivalent of diacyl bromohalomonocyclide, and the amount of aluminum chloride used is 2.0 per equivalent of diacyl bromohalomonocyclide. To 6.0 equivalents are preferred. Further, for example, trifluoroacetic acid / triethylsilane can be used as a reducing agent, and the reaction can be performed in a temperature range of −10 to 40 ° C. The amount of trifluoroacetic acid used is preferably 10 to 50 equivalents relative to 1 equivalent of diacyl bromohalomonocyclide, and the amount of triethylsilane used is 1.8 to 6.0 equivalents relative to 1 equivalent of diacyl bromohalomonocyclized. Is preferred.

  Step (E1) is a step of producing a dithienobenzodifuran derivative by subjecting a dialkyl form of a bromohalomonocyclized product to dilithiation with n-butyllithium / cyclization reaction with bis (phenylsulfonyl) sulfide.

  The cyclization reaction can be performed in a temperature range of −80 to 30 ° C. in a solvent such as THF and diethyl ether. The amount of n-butyllithium used is preferably 1.8 to 2.8 equivalents relative to 1 equivalent of dialkyl bromohalomonocyclide, and the amount of bis (phenylsulfonyl) sulfide used is 1 equivalent of bromohalomonocyclized dialkyl. 0.9 to 1.5 equivalents are preferred.

Further, if the substituents R ¹ and R ² to produce a di-thieno benzodioxanyl furan derivative is an alkyl group having 1 to 12 carbon atoms, by a production method through the steps below (A2) ~ (E2), Jichienobenzo Difuran derivatives can also be produced.

  Step (A2): 1,4-di (3-bromofuryl) -2 by palladium-catalyzed cross-coupling of a 3-bromofuran-2-zinc derivative and 1,4-dibromo-2,5-dihalobenzene in the presence of a palladium catalyst. , 5-Dihalobenzene production step.

  (B2) Step; A step of producing a bromohalomonocyclized product by a monomolecular cyclization reaction using 1,4-di (3-bromofuryl) -2,5-dihalobenzene obtained by the step (A2) and sodium sulfide.

(C2) Step; Substituent represented by the general formula (1) by a method in which the bromohalomonocyclized product obtained in Step (B2) is dilithiated with n-butyllithium / a second ring is formed with bis (phenylsulfonyl) sulfide. A step of producing a compound (unsubstituted dithienobenzodifuran) in which R ¹ and R ² are hydrogen.

  Step (D2): In the presence of aluminum chloride as a catalyst, Dithieno is obtained by a Friedel-Crafts acylation reaction between the unsubstituted dithienobenzodifuran obtained in Step (C2) and an acyl chloride compound having 1 to 12 carbon atoms. The process of manufacturing the diacyl body of benzodifuran.

  (E2) Step; (D2) A step of producing a dithienobenzodifuran derivative by subjecting the diacyl derivative of dithienobenzodifuran obtained in the step to a reduction reaction.

  A preferred more specific production method is shown in the following reaction scheme 2.

(Here, the substituent X ¹ represents fluorine and iodine, the substituent X ² represents fluorine and bromine, and the substituent R ³ represents hydrogen and an alkyl group having 1 to 11 carbon atoms.)
The manufacturing conditions from the (A1) process to the (E1) process of the said manufacturing method can be applied to the manufacturing conditions from the (A2) process to the (E2) process of this manufacturing method.

  In step (B2), the amount of sodium sulfide used is 1.8 to 3.5 equivalents per 1 equivalent of 1,4-di (3-bromofuryl) -2,5-dihalobenzene, and is used in a solvent such as NMP or DMF. The unsubstituted dithienobenzodifuran can also be synthesized by a method carried out in the temperature range of 120 to 200 ° C.

When producing a dithienobenzodifuran derivative in which the substituents R ¹ and R ² are an aryl group having 4 to 14 carbon atoms, a compound in which the substituents R ¹ and R ² are hydrogen atoms (unsubstituted dithienobenzodifuran) ) Is used as a raw material, and the dithienobenzodifuran derivative is preferably produced by a production method through the following steps (A3) and (B3).

  Step (A3): A step of producing dibromodithienobenzodifuran by bromination of unsubstituted dithienobenzodifuran with N-bromosuccinimide (hereinafter referred to as NBS) and bromine.

  Step (B3): In the presence of a palladium catalyst, a dithienobenzodifuran derivative is produced by palladium-catalyzed cross coupling of dibromodithienobenzodifuran obtained in step (A3) and an aryl zinc derivative having 4 to 14 carbon atoms. Process.

  A preferred more specific production method is shown in Reaction Scheme 3 below.

(Here, the substituent Ar represents an aryl group having 4 to 14 carbon atoms.)
Step (A3) is bromination of unsubstituted dithienobenzodifuran, and NBS is preferred as a brominating agent, and is carried out in a temperature range of −30 to 50 ° C. in a solvent such as THF, DMF, chloroform, and acetic acid. To do. The bromination reaction is preferably performed under light shielding. The amount of NBS used is preferably 1.8 to 3.2 equivalents per equivalent of unsubstituted dithienobenzodifuran.

  The palladium-catalyzed cross coupling in step (B3) can be carried out in a temperature range of 20 to 100 ° C. in a solvent such as THF, diethyl ether, or toluene. Examples of the palladium catalyst include tetrakis (triphenylphosphine) palladium and bis (triphenylphosphine) dichloropalladium. The amount of the catalyst used is 0.1 to 1 mol of dibromodithienobenzodifuran. 10 mol% is preferable. The amount of the arylzinc derivative having 4 to 14 carbon atoms is preferably 1.8 to 3.0 equivalents per 1 equivalent of dibromodithienobenzodifuran.

In the case of producing a dithienobenzodifuran derivative in which the substituents R ¹ and R ² are alkynyl groups having 2 to 14 carbon atoms, dibromodithienobenzodifuran obtained in the step (A3) and 2 to 2 carbon atoms are produced. Dithienobenzodifuran derivatives can be prepared by palladium / copper iodide catalyzed cross coupling of 14 alkyne derivatives (Soto coupling). A preferred more specific production method is shown in Reaction Scheme 4 below.

(Here, the substituent R ⁴ represents hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 1 to 12 carbon atoms.)
The palladium / copper iodide-catalyzed cross coupling can be carried out in a temperature range of 0 to 80 ° C. in a solvent such as THF, toluene and DMF and an amine such as triethylamine and pyridine. Examples of the palladium catalyst include tetrakis (triphenylphosphine) palladium and bis (triphenylphosphine) dichloropalladium. The amount of the catalyst used is 0.1 to 1 mol of dibromodithienobenzodifuran. 10 mol% is preferable. The amount of the alkyne derivative having 2 to 14 carbon atoms is preferably 1.8 to 3.0 equivalents per 1 equivalent of dibromodithienobenzodifuran.

In the case of producing a dithienobenzodifuran derivative in which the substituents R ¹ and R ² are alkenyl groups having 2 to 14 carbon atoms, dibromodithienobenzodifuran obtained in the above-described step (A3) and 2 to 2 carbon atoms. Dithienobenzodifuran derivatives can be produced by palladium-catalyzed cross coupling (Heck reaction) of 14 alkene derivatives. A preferred more specific production method is shown in the following reaction scheme 5.

(Here, the substituent R ⁵ represents hydrogen, an alkyl group having 1 to 12 carbon atoms, or an aryl group having 1 to 12 carbon atoms.)
The palladium-catalyzed cross coupling can be carried out in a temperature range of 20 to 140 ° C. in a solvent such as THF, toluene, and DMF and an amine such as triethylamine, tripropylamine, and pyridine. Examples of the palladium catalyst include tetrakis (triphenylphosphine) palladium, bis (triphenylphosphine) dichloropalladium and the like. The catalyst is 0.1 to 10 mol% with respect to 1 mol of dibromodithienobenzodifuran. Used within the range of The amount of the alkene derivative having 2 to 14 carbon atoms is preferably 1.8 to 3.0 equivalents per 1 equivalent of dibromodithienobenzodifuran.

  Moreover, as a manufacturing method of the dithienobenzodifuran of this invention, it can also implement by the manufacturing method which passes through the process of the following (A6)-(C6) using the intramolecular cyclization of a methylsulfinyl group.

(A6) Step: A step of synthesizing a compound in which a metal is introduced into the 5-position by lithiation of furan having an R ¹ substituent at the 2-position with n-butyllithium and reaction with zinc chloride, trimethoxyborane or the like.

  (B6) step; bis (methylsulfinyl) by palladium-catalyzed cross-coupling of the furan compound obtained in step (A6) and 1,4-dibromo-2,5-bis (methylsulfinyl) benzene in the presence of a palladium catalyst Producing a derivative;

  Step (C6): After reacting the bis (methylsulfinyl) derivative obtained in Step (B6) with trifluoromethanesulfonic acid and diphosphorus pentoxide, the compound represented by the general formula (1) Of producing a dithienobenzodifuran derivative of

  A preferred more specific production method is shown in Reaction Scheme 6 below.

Among the benzodifuran derivatives of the present invention, a compound in which T ¹ and T ² are oxygen, that is, a difuranobenzodifuran derivative can be produced by any production method as long as the difuranobenzodifuran derivative can be produced. It is also possible to use. For example, when a difuranobenzodifuran derivative is produced, a difuranobenzodifuran derivative in which the substituents R ¹ and R ² are hydrogen is produced by a production method through the following steps (A7) to (C7). Can do.

  (A7) Step: 1,4-di (3-bromofuryl) -2,5-dimethoxy with 3-bromofuran-2-boronic acid derivative and 1,4-dibromo-2,5-dimethoxybenzene in the presence of a palladium catalyst A process for producing benzene.

  Step (B7); 1,4-di (3) by demethylation of 1,4-di (3-bromofuryl) -2,5-dimethoxybenzene obtained in Step (A7) in the presence of boron tribromide. -Bromofuryl) -2,5-dihydroxybenzene production step.

Step (C7): In the presence of a palladium catalyst, the substituents R ¹ and R ² are converted by intramolecular cyclization of 1,4-di (3-bromofuryl) -2,5-dihydroxybenzene obtained in Step (B7). A process for producing difuranobenzodifuran, which is hydrogen.

  A more preferred production method is shown in the following reaction scheme 7.

  Here, the step (A7) can be carried out under the same reaction conditions as in the step (A1) of the aforementioned reaction scheme 1.

  Step (B7) is carried out by demethylation of 1,4-di (3-bromofuryl) -2,5-dimethoxybenzene in the presence of boron tribromide, and 1,4-di (3-bromofuryl) -2,5. -A process for producing dihydroxybenzene.

  The demethylation reaction can be performed in a temperature range of 0 to 30 ° C. in a solvent such as dichloromethane and chloroform.

Step (C7) is a difuranobenzodi wherein the substituents R ¹ and R ² are hydrogen by intramolecular cyclization of 1,4-di (3-bromofuryl) -2,5-dihydroxybenzene in the presence of a palladium catalyst. This is a process for producing furan.

  The intramolecular cyclization reaction is performed using, for example, palladium acetate as a catalyst, 2-ditertiarybutylphosphinobiphenyl, 2-ditertiarybutylphosphino-2′-methylbiphenyl as a ligand, and 2,6-ditertiarybutyl. It can be carried out in a temperature range of 80 to 120 ° C. in a solvent such as toluene and dimethoxyethane in the presence of potassium acetate base using -4-methylphenol as a stabilizer.

  Other examples of the palladium catalyst include tetrakis (triphenylphosphine) palladium and bis (triphenylphosphine) dichloropalladium.

  In addition, this cyclization reaction can also be implemented, for example using the method described in Journal of Organic Chemistry (USA), 2007, 72, 5119-5128.

Furthermore, regarding the method for producing difuranobenzodifurans in which the substituents R ¹ and R ² are other than hydrogen, they can be introduced by the methods described in Reaction Schemes 2 to 5 above.

  Furthermore, the produced benzodifuran derivative can be purified by subjecting it to column chromatography and the like, and examples of the separating agent include silica gel and alumina, and examples of the solvent include hexane, heptane, toluene and chloroform. Can do.

  The produced benzodifuran derivative may be further purified by recrystallization, and the number of recrystallizations is preferably 2 to 5 times. Purity can be improved by increasing the number of recrystallizations. Examples of the solvent used for recrystallization include hexane, heptane, octane, toluene, xylene, chloroform, chlorobenzene, dichlorobenzene, and the like, and a mixture of any ratio thereof may be used. As the recrystallization method, a solution of a benzodifuran derivative is prepared by heating (the concentration of the solution is preferably in the range of 0.01 to 10.0% by weight, more preferably in the range of 0.05 to 5.0% by weight). Preferably, the solution is cooled to precipitate and isolate crystals of the benzodifuran derivative, and the final cooling temperature in the isolation is preferably -20 to 40 ° C. In addition, when measuring purity, it can measure by analyzing by liquid chromatography.

  The organic semiconductor layer forming solution of the present invention contains the benzofuran derivative and a solvent, and the concentration of the benzofuran derivative in the solution is suitable for film formation by a drop casting method, particularly an ink jet method or a slit coating method. Therefore, it is preferable that the solubility is 1.0% by weight or more with respect to the solvent at room temperature.

  Examples of the solvent used include toluene, xylene, mesitylene, ethylbenzene, pentylbenzene, hexylbenzene, octylbenzene, cyclohexylbenzene, indane, tetralin, anisole, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, 1,2- C7-14 aromatic hydrocarbon solvents such as dimethylanisole, 2,3-dimethylanisole, 3,4-dimethylanisole; fats having 6-14 carbon atoms such as hexane, heptane, octane, decane, dodecane, and tetradecane Group hydrocarbon solvents; halogen solvents having 1 to 7 carbon atoms such as o-dichlorobenzene, chlorobenzene, trichlorobenzene, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chloroform, dichloromethane; THF, , 2-Dimet Ether solvents such as sietan and dioxane; ketone solvents such as acetone, methyl ethyl ketone, diethyl ketone, diisopropyl ketone and acetophenone; ester solvents such as ethyl acetate, γ-butyrolactone, cyclohexanol acetate and 3-methoxybutyl acetate; DMF, Amide solvents such as NMP; dipropylene glycol dimethyl ether, dipropylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol Diacetate, 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, ethylene glycol monomethyl ether acetate, propylene Examples include glycol solvents such as lenglycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate. Among them, it is possible to obtain a high boiling point solution, toluene, It is preferably an aromatic hydrocarbon solvent having 7 to 14 carbon atoms such as xylene, mesitylene, ethylbenzene, pentylbenzene, cyclohexylbenzene, tetralin, 3,4-dimethylanisole, particularly mesitylene, cyclohexylbenzene, tetralin, 3, 4 -Dimethylanisole is preferred. Here, room temperature is generally referred to as room temperature, and examples thereof include a temperature of 20 to 26 ° C.

  A solution for forming an organic semiconductor layer containing the benzodifuran derivative represented by the general formula (1) is prepared by mixing the solvent listed above and the benzodifuran derivative represented by the general formula (1), and heating and stirring. Can do. The temperature during heating and stirring is preferably 15 to 70 ° C, particularly preferably 20 to 60 ° C. The concentration of the benzodifuran derivative represented by the general formula (1) at the time of heating and stirring is preferably 0.1 to 10.0% by weight.

  In addition, since the benzodifuran derivative itself has appropriate cohesiveness, the solution can be prepared at a relatively low temperature and has oxidation resistance, so that the solution can be suitably applied to the production of an organic thin film by a coating method. . That is, since it is not necessary to remove air from the atmosphere, the coating process can be simplified. Further, the solution may be, for example, polystyrene, poly-α-methylstyrene, polyvinyl naphthalene, ethylene-norbornene copolymer, polymethyl methacrylate, polytriarylamine, poly (9,9-dioctylfluorene-co-dimethyltriarylamine), etc. A polymer can also be present as a binder. The concentration of these polymer binders is preferably 0.1 to 10.0% by weight, and since the solution has excellent coating properties, it has a viscosity in the range of 0.5 to 50 mPa · s. Is preferred.

  The benzodifuran derivative contained in the organic semiconductor layer forming solution of the present invention has excellent characteristics as an organic semiconductor material because it imparts high carrier mobility, and has high solubility in a solvent. The organic semiconductor layer can be easily and efficiently formed from the contained organic semiconductor layer forming solution by a method such as a drop casting method, particularly an ink jet method.

  The organic thin film transistor is obtained by laminating an organic semiconductor layer provided with a source electrode and a drain electrode on a substrate and a gate electrode through an insulating layer, and the organic semiconductor layer is formed from the benzodifuran derivative of the present invention. By using such an organic semiconductor layer, an organic thin film transistor can be obtained.

  FIG. 1 shows a structure of a general organic thin film transistor by a sectional shape. Here, (A) is a bottom gate-top contact type, (B) is a bottom gate-bottom contact type, (C) is a top gate-top contact type, and (D) is a top gate-bottom contact type. 1 is an organic semiconductor layer, 2 is a substrate, 3 is a gate electrode, 4 is a gate insulating layer, 5 is a source electrode, 6 is a drain electrode, and the organic semiconductor layer made of the benzodifuran derivative of the present invention is It can be applied to any organic thin film transistor.

  Examples of the substrate include polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polymethyl acrylate, polyethylene, polypropylene, polystyrene, cyclic polyolefin, polyimide, polycarbonate, polyvinyl phenol, polyvinyl alcohol, poly (diisopropyl fumarate), poly ( (Diethyl fumarate), poly (diisopropyl maleate), polyethersulfone, polyphenylene sulfide, cellulose triacetate and other plastic substrates; glass, quartz, aluminum oxide, silicon, highly doped silicon, silicon oxide, tantalum dioxide, tantalum pentoxide, indium Inorganic material substrates such as tin oxide; Metal substrates such as gold, copper, chromium, titanium, aluminum, etc. Can. When highly doped silicon is used for the substrate, the substrate can also serve as the gate electrode.

  As the gate electrode, for example, aluminum, gold, silver, copper, highly doped silicon, tin oxide, indium oxide, indium tin oxide, chromium, titanium, tantalum, chromium, graphene, carbon nanotube and other inorganic materials; doped An organic material such as a conductive polymer (for example, PEDOT-PSS) can be given.

  Examples of the gate insulating layer include inorganic materials such as silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, titanium oxide, tantalum dioxide, tantalum pentoxide, indium tin oxide, tin oxide, vanadium oxide, barium titanate, and bismuth titanate. Material substrate: polymethyl methacrylate, polymethyl acrylate, polyimide, polycarbonate, polyvinyl phenol, polyvinyl alcohol, poly (diisopropyl fumarate), poly (diethyl fumarate), polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polycyclopentane, Polycyclohexane, polycyclohexane-ethylene copolymer, polyfluorinated cyclopentane, polyfluorinated cyclohexane, polyfluorinated cyclohexane-ethylene The plastic material of the polymer, and the like can be given. The surfaces of these gate insulating layers are, for example, octadecyltrichlorosilane, decyltrichlorosilane, decyltrimethoxysilane, octyltrichlorosilane, octadecyltrimethoxysilane, β-phenethyltrichlorosilane, β-phenethyltrimethoxysilane, phenyltrichlorosilane. Silanes such as phenyltrimethoxysilane; phosphonic acids such as octadecylphosphonic acid, decylphosphonic acid and octylphosphonic acid, and those modified with silylamines such as hexamethyldisilazane can also be used. In general, the surface treatment of the gate insulating layer is preferable in order to increase the crystal grain size and molecular orientation of the organic semiconductor material, and to improve the carrier mobility and current on / off ratio, and to lower the threshold voltage. Results are obtained.

  As a material of the source electrode and the drain electrode, the same material as that of the gate electrode can be used, and the material may be the same as or different from the material of the gate electrode, or different materials may be stacked. In order to increase the carrier injection efficiency, surface treatment can be performed on these electrode materials. Examples thereof include benzene thiol and pentafluorobenzene thiol.

  When the organic semiconductor layer made of the benzodifuran derivative of the present invention is used as the organic semiconductor layer, for example, a drop casting method such as spin coating, cast coating, ink jet, slit coating, etc .; blade coating; dip coating, screen printing, gravure It is possible to use a method such as printing, flexographic printing, etc. Among them, it is possible to easily and efficiently form an organic semiconductor layer, so that it is a drop cast method such as spin coating, cast coating, ink jet, etc. Particularly preferred is an ink jet. Moreover, there is no restriction | limiting in the film thickness of the organic-semiconductor layer in that case, Preferably it is 1 nm-1 micrometer, Most preferably, it is 10-300 nm.

  The organic semiconductor layer containing the benzodifuran derivative of the present invention can be annealed at 40 to 200 ° C. after coating and drying.

  The benzodifuran derivative of the present invention is used for an organic semiconductor layer of an electronic paper, an organic EL display, a liquid crystal display, an IC tag (RFID tag), a transistor such as a pressure sensor; an organic EL display material; an organic semiconductor laser material; Materials: Can be used for electronic materials such as photonic crystal materials.

  The novel benzodifuran derivative of the present invention is a coating-type organic semiconductor material that gives high carrier mobility and has high heat resistance and high solubility, and the present invention is a novel organic semiconductor material that solves the conventional problems As a semiconductor device material typified by an organic thin film transistor, the effect is extremely high.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

For the identification of the product, ¹ H-NMR spectrum and mass spectrum were used. The ¹ H NMR spectrum uses JEOL GSX-400 (400 MHz) manufactured by JEOL, and the mass spectrum (MS) uses JEOL JMS-700 (trade name) manufactured by JEOL. It was measured by the (EI) method (70 electron volts).

  Confirmation of the progress of the reaction was performed by thin layer chromatography, gas chromatography (GC) and gas chromatography-mass spectrum (GCMS) analysis.

Gas chromatography analyzer; manufactured by Shimadzu Corporation (trade name) GC14B
Column; made by J & W Scientific, (trade name) DB-1, 30 m
Gas chromatography-mass spectrum analyzer; manufactured by PerkinElmer, (trade name) Auto System XL (MS unit: Turbomass Gold)
Column; J & W Scientific (trade name) DB-1, 30 m.

Liquid chromatographic analysis was used to measure the purity of the benzodifuran derivative.
Device: manufactured by Tosoh (controller; PX-8020, pump; CCPM-II, degasser; SD-8022)
Column: manufactured by Tosoh (trade name) ODS-100V, 5 μm, 4.6 mm × 250 mm
Column temperature: 23 ° C
Eluent; dichloromethane: acetonitrile = 3: 7 (volume ratio)
Flow rate: 1.0 ml / min detector; UV (manufactured by Tosoh, (trade name) UV-8020, wavelength: 254 nm).

Synthesis Example 1 Synthesis of 1,4-dibromo-2,5-diiodobenzene 1,4-dibromo-2,5-diiodobenzene is described in Journal of American Chemical Society, 1997, 119, 4578-4593. The synthesis was carried out as follows with reference to the method.

Periodic acid 16.7 g (73.0 mmol) and sulfuric acid 525 ml were added to a 1 l three-necked flask equipped with a mechanical stirrer. After the periodic acid was dissolved, 36.4 g (219 mmol) of potassium iodide was added little by little. The temperature of the contents was cooled to −30 ° C., and 34.5 g (146 mmol) of 1,4-dibromobenzene was added over 5 minutes. The resulting mixture was stirred at −25 ° C. for 36 hours. The reaction mixture was poured into ice (2 Kg) and filtered to remove the solid. The solid was dissolved in chloroform, washed with 5% aqueous sodium hydroxide solution and water, and the organic phase was dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was recrystallized from chloroform to obtain 36.0 g of white crystals (yield 50%).
¹ H NMR (CDCl ₃ , 21 ° C.): δ = 8.02 (s, 2H).
It was confirmed that 1,4-dibromo-2,5-diiodobenzene was obtained because the ¹ H NMR spectrum was consistent with the literature value.

Synthesis Example 2 (Synthesis of 1,4-di (3-bromofuryl) -2,5-dibromobenzene (reaction scheme 1, step (A1)))
Under a nitrogen atmosphere, 2.950 g (13.06 mmol) of 2,3-dibromofuran (manufactured by Sigma-Aldrich) and 19 ml of THF (dehydrated grade) were added to a 100 ml Schlenk reaction vessel. The mixture was brought to −20 ° C., and 6.6 ml (13.2 mmol) of a THF solution of ethylmagnesium chloride (manufactured by Sigma-Aldrich, 2.0M) was added dropwise. By aging at −20 ° C. for 30 minutes, 3-bromo-2-furylmagnesium chloride was prepared. On the other hand, 1.83 g (13.4 mmol) of zinc chloride (manufactured by Wako Pure Chemical Industries) and 20 ml of THF (dehydrated grade) were added to another 100 ml Schlenk reaction vessel and cooled to -20 ° C. Here, the previously prepared THF solution of 3-bromo-2-furylmagnesium chloride was charged using a Teflon (registered trademark) cannula. After reacting at −20 ° C. for 30 minutes and aging at room temperature for 30 minutes, a THF solution of 3-bromo-2-furyl zinc chloride was prepared. Here, 2.66 g (5.45 mmol) of 1,4-dibromo-2,5-diiodobenzene synthesized in Synthesis Example 1 and 32.1 mg of tetrakis (triphenylphosphine) palladium (manufactured by Tokyo Chemical Industry) as a catalyst ( 0.0278 mmol, 0.51 mol% with respect to 1,4-dibromo-2,5-diiodobenzene) was added. After carrying out the reaction at 60 ° C. for 8 hours, the vessel was cooled with water and the reaction was stopped by adding 3 ml of 3N hydrochloric acid. Extraction was performed with toluene, and the organic phase was washed with brine and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was purified by silica gel short column chromatography (toluene), and the resulting concentrate was washed with hexane and further recrystallized and purified from heptane / toluene (= 2/1 vol%). A pale yellow solid of 1.13 g of 4-di (3-bromofuryl) -2,5-dibromobenzene was obtained (39% yield).
¹ H-NMR (CDCl ₃ , 24 ° C.): δ = 7.81 (s, 2H), 7.52 (d, J = 1.9 Hz, 2H), 6.59 (d, J = 1.9 Hz, 2H).
MS m / z: 527 (M ^{++ 2,} 67%), 525 (M ⁺ , 100%), 523 (M ⁺ -2, 69%), 446 (M ⁺ -Br + 1, 5).

Synthesis Example 3 (Synthesis of dibromomonocyclized product (reaction scheme 1, step (B1)))
Under a nitrogen atmosphere, 1.02 g (1.95 mmol) of 1,4-di (3-bromofuryl) -2,5-dibromobenzene synthesized in Synthesis Example 2 and 40 ml of NMP (dehydrated grade) were added to a 200 ml Schlenk reaction vessel. . To this mixture, 189 mg (2.42 mmol) of ground sodium sulfide (anhydrous grade, manufactured by Wako Pure Chemical Industries, Ltd.) was added. The resulting mixture was heated at 140 ° C. for 5 hours. The obtained reaction solution was ice-cooled, and the reaction was stopped by adding 5 ml of 1N hydrochloric acid. Extraction was performed with toluene, the organic phase was washed twice with water, and the organic phase was dried over anhydrous sodium sulfate. The residue was purified by silica gel column chromatography (heptane / toluene (= 2/1 vol%)) to obtain 596 mg of a dibromomonocyclized solid (yield 77%).
¹ H-NMR (CDCl ₃ , 24 ° C.): δ = 8.18 (s, 1H), 7.89 (s, 1H), 7.71 (d, J = 1.9 Hz, 1H), 7.51 (D, J = 1.9 Hz, 1H), 6.86 (d, J = 1.9 Hz, 1H), 6.59 (d, J = 1.9 Hz, 1H).
MS m / z: 400 (M ^{++ 2,} 51%), 398 (M ⁺ , 100%), 396 (M ⁺ -2, 49), 319 (M ⁺ -Br + 1, 18).

Synthesis Example 4 (Synthesis of dihexanoyl dibromomonocyclized product (reaction scheme 1, step (C1)))
Under a nitrogen atmosphere, 158 mg (1.17 mmol) of hexanoyl chloride (manufactured by Sigma-Aldrich) and 10 ml of dichloromethane (dehydrated grade) were added to a 100 ml Schlenk reaction vessel. The mixture was cooled to −25 ° C., 165 mg (1.23 mmol) of aluminum chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred for 5 minutes. The obtained mixture was cooled to −70 ° C., and a solution consisting of 191 mg (0.479 mmol) of the dibromomonocyclized product synthesized in Synthesis Example 3 and 4 ml of dichloromethane (dehydrated grade) was added. After heating up to -20 degreeC over 2 hours, the reaction was stopped by adding water. Extracted with dichloromethane and the organic phase was washed twice with water and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was purified by silica gel column chromatography (hexane / dichloromethane (= 5/1 vol% to 1/2 vol%)) to obtain 199 mg of a dibromomonocyclized dihexanoyl compound (yield 70%). ).
¹ H-NMR (CDCl ₃ , 24 ° C.): δ = 8.36 (s, 1H), 7.99 (s, 1H), 7.58 (s, 1H), 7.31 (s, 1H), 2.96 (t, J = 7.1 Hz, 2H), 2.86 (d, J = 7.1 Hz, 2H), 1.84 to 1.68 (m, 4H), 1.44 to 1.25 (M, 8H), 0.98-0.87 (m, 6H).
MS m / z: 596 (M ^{++ 2,} 56%), 594 (M ⁺ , 100%), 592 (M ⁺ -2, 51%).

Synthesis Example 5 (Synthesis of dihexyl form of dibromomonocyclized product (reaction scheme 1, step (D1)))
Under a nitrogen atmosphere, 184 mg (0.309 mmol) of the dibromomonocyclized dihexanoyl compound synthesized in Synthesis Example 4 and 0.7 ml of trifluoroacetic acid (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a 100 ml Schlenk reaction vessel. This mixture was ice-cooled, and 244 mg (2.10 mmol) of triethylsilane (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After reaction at room temperature for 18 hours, the reaction was stopped by cooling with ice and adding an aqueous sodium hydrogen carbonate solution. Extracted with toluene, the organic phase was washed twice with water and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the obtained residue was purified by silica gel column chromatography (hexane / toluene (= 15/1 vol%)) to obtain 119 mg of dihexyl dicyclohexyl monocycle (yield 68%).
MS m / z: 568 (M ^{++ 2,} 50%), 566 (M ⁺ , 100%), 564 (M ⁺ -2, 53%).

Example 1 (Synthesis of di-n-hexyldithienobenzodifuran (Reaction Scheme 1, Step (E1)))
In a 100 ml Schlenk reaction vessel, 119 mg (0.210 mmol) of the dibromomonocyclized dihexyl compound synthesized in Synthesis Example 5 and 5 ml of THF (dehydrated grade) were added under a nitrogen atmosphere. The obtained mixture was cooled to −78 ° C., and 0.28 ml (0.46 mmol) of a hexane solution of n-butyllithium (manufactured by Kanto Chemical Co., Ltd., 1.66 M) was added dropwise. After reacting at −78 ° C. for 10 minutes, 72.3 mg (0.230 mmol) of bis (phenylsulfonyl) sulfide (manufactured by Acros) was added, and the temperature was gradually raised. After 18 hours, when the temperature rose to 5 ° C., water was added. Extraction with toluene was performed, and the organic phase was washed once with water and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was purified by silica gel column chromatography (hexane / toluene (= 20/1 vol%) and recrystallized twice from hexane to obtain di-n-hexyldithienobenzodifuran white. 53.4 mg of crystals were obtained (58% yield).
Melting point: 141 ° C
¹ H-NMR (C ₆ D ₆ , 24 ° C.): δ = 8.01 (s, 2H), 6.05 (s, 2H), 2.54 (t, J = 7.2 Hz, 4H), 1 .58 (m, 4H), 1.24 (m, 12H), 0.88 (t, J = 7.2 Hz, 6H).
_{^{MS m / z: 438 (M}} +, 100%), 367 (M + -C 5 H 11, 49), 296 (M + -2C 5 H 11, 22).

Synthesis Example 6 (Synthesis of dibutyl monobromo product (reaction scheme 1, steps (C1) and (D1)))
The same procedure as in Synthesis Example 4 was repeated except that butanoyl chloride was used instead of hexanoyl chloride in Synthesis Example 4 to synthesize a dibutanoyl form of dibromomonocyclized product (yield 73%).

Further, the same procedure as in Synthesis Example 5 was repeated except that the dibutanoyl dibromomonocyclide was used instead of the dihexanoyl dibromomonocyclide in Synthesis Example 5 to synthesize a dibutyl monobromomonocyclide (recovery). Rate 60%).
MS m / z: 512 (M ^{++ 2,} 55%), 510 (M ⁺ , 100%), 508 (M ⁺ -2, 52%).

Example 2 (Synthesis of di-n-butyldithienobenzodifuran (reaction scheme 1, step (E1)))
The same procedure as in Example 1 was repeated except that the dibutyl monobromo product obtained in Synthesis Example 6 was used in place of the dihexyl dibromo monocyclide in Example 1, and di n-butyl dithieno was used. Benzodifuran was synthesized (54% yield).
Melting point: 152 ° C
¹ H-NMR (C ₆ D ₆ , 24 ° C.): δ = 8.02 (s, 2H), 6.06 (s, 2H), 2.54 (t, J = 7.2 Hz, 4H), 1 .58 (m, 4H), 1.35 (m, 4H), 0.96 (t, J = 7.2 Hz, 6H).
_{^{MS m / z: 382 (M}} +, 100%), 339 (M + -C 3 H 7, 45), 296 (M + -2C 3 H 7, 20).

Example 3 (Synthesis of dithienobenzodifuran (reaction scheme 2, step (C2)))
Under a nitrogen atmosphere, 80.0 mg (0.200 mmol) of the dibromomonocyclized product synthesized in Synthesis Example 3 and 5 ml of THF (dehydrated grade) were added to a 100 ml Schlenk reaction vessel. The obtained mixture was cooled to −78 ° C., and 0.27 ml (0.45 mmol) of a hexane solution of n-butyllithium (manufactured by Kanto Chemical Co., Ltd., 1.66 M) was added dropwise. After reacting at −78 ° C. for 2 minutes, a solution consisting of 69.7 mg (0.221 mmol) of bis (phenylsulfonyl) sulfide (manufactured by Acros) and 3 ml of THF (dehydrated grade) was added, and the temperature was gradually raised. After 18 hours, when the temperature rose to 5 ° C., water was added. Extraction with toluene was performed, and the organic phase was washed once with water and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was purified by silica gel column chromatography (hexane / toluene (= 3/1 vol%), and recrystallized once from hexane to obtain 27.7 mg of dithienobenzodifuran white solid. (51% yield) was obtained.
¹ H-NMR (C ₆ D ₆ , 24 ° C.): δ = 7.91 (s, 2H), 7.09 (d, J = 1.6 Hz, 2H), 6.20 (d, J = 1. 6Hz, 2H).
MS m / z: 270 (M ^<+> , 100%).

Example 4 (Synthesis of dibromodithienobenzodifuran (reaction scheme 3, step (A3)))
Under a nitrogen atmosphere, 50.0 mg (0.184 mmol) of dithienobenzodifuran synthesized in Example 3 and 10 ml of THF (dehydrated grade) were added to a 100 ml Schlenk reaction vessel. The obtained mixture was shielded from light and 98.2 mg (0.552 mmol) of NBS (manufactured by Wako Pure Chemical Industries) was added. 2 ml of DMF was added and stirred at room temperature for 18 hours. Water was added, extracted with toluene, and the organic phase was washed once with water and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the obtained residue was washed with hexane, and the residue was vacuum-dried to obtain 61.4 mg of dibromodithienobenzodifuran (yield 78%).
MS m / z: 430 (M ⁺ +2, 56%), 428 (M ⁺ , 100%), 426 (M ⁺ −2, 51%).

Example 5 (Synthesis of bis {5- (n-pentyl) -2-furyl} dithienobenzodifuran (Reaction Scheme 3, Step (B3)))
Under a nitrogen atmosphere, 59.2 mg (0.429 mmol) of 2-pentylfuran (manufactured by Wako Pure Chemical Industries) and 4 ml of THF (dehydrated grade) were added to a 100 ml Schlenk reaction vessel. The mixture was cooled to −78 ° C., and 0.39 ml (0.64 mmol) of a hexane solution of n-butyllithium (manufactured by Kanto Chemical Co., Ltd., 1.66 M) was added dropwise. The mixture was heated to 0 ° C. and then cooled again to −78 ° C. On the other hand, 72.2 mg (0.529 mmol) of zinc chloride (manufactured by Wako Pure Chemical Industries) and 4 ml of THF (dehydrated grade) were added to another 100 ml Schlenk reaction vessel and cooled to -78 ° C. Here, the THF solution of 2-pentyl-5-furyllithium prepared previously was charged using a Teflon (registered trademark) cannula. The solution was gradually warmed to room temperature and aged to prepare a THF solution of 2-pentyl-5-furylzinc chloride. Here, 61.4 mg (0.143 mmol) of dibromodithienobenzodifuran synthesized in Example 4, and 4.6 mg (0.00398 mmol, dibromodithieno) tetrakis (triphenylphosphine) palladium (manufactured by Tokyo Chemical Industry Co., Ltd.) as a catalyst. 2.8 mol% relative to 1 mol of benzodifuran). After carrying out the reaction at 60 ° C. for 5 hours, the reaction was stopped by cooling the vessel with water and adding 3 ml of 1N hydrochloric acid. Extraction was performed with toluene, and the organic phase was washed with brine and dried over anhydrous sodium sulfate. After concentration under reduced pressure, the resulting residue was purified by silica gel short column chromatography (toluene), and the resulting concentrate was washed with hexane and further recrystallized from toluene to give bis {5- (n-pentyl) -2. 32.5 g of pale yellow crystals of -furyl} dithienobenzodifuran were obtained (42% yield).
Melting point: 216 ° C
MS m / z: 542 (M ⁺ , 100%), 485 (M ⁺ -57, 32%).

Example 6
12.6 mg of di-n-hexyldithienobenzodifuran synthesized in Example 1 and 617 mg of toluene (Pure Grade manufactured by Wako Pure Chemical Industries, Ltd.) were added, dissolved by heating at 50 ° C., and then allowed to cool at room temperature (25 ° C.). Then, a solution for forming a drop cast organic semiconductor layer was prepared. The solution state is maintained even after 10 hours at 25 ° C. (di-n-hexyldithienobenzodifuran concentration is 2.0% by weight), and it is confirmed that the compound is suitable for film formation by drop casting and ink jet. did.

  And the drop cast obtained on a silicon substrate (semi-tech, resistance value: 0.001 to 0.004Ω, with a silicon oxide film of 200 nm on the surface) that is n-type highly doped with arsenic having a diameter of 2 inches under air A microsyringe was filled with 0.2 ml of the organic semiconductor layer forming solution and drop-cast. The organic semiconductor layer of di n-hexyl dithienobenzodifuran having a film thickness of 58 nm was produced by natural drying at room temperature (25 ° C.).

  A shadow mask having a channel length of 30 μm and a channel width of 250 μm was placed on the organic semiconductor layer, and gold was vacuum-deposited to form a source / drain electrode pair, thereby producing a bottom gate-top contact type p-type organic thin film transistor.

Using the semiconductor parameter analyzer (Keutley 4200SCS), the electrical properties of the fabricated organic thin film transistor were scanned with a drain voltage (Vd = -50V) and a gate voltage (Vg) from +5 to -60V in 1V increments, and the transfer characteristics were evaluated. Went. The hole carrier mobility was 0.76 cm ² / V · s, and the current on / off ratio was 2.1 × 10 ⁷ .

Furthermore, the electrical properties of the organic thin film transistor after annealing at 130 ° C. for 15 minutes were measured. The carrier mobility of holes was 0.69 cm ² / V · s, the current on / off ratio was 1.2 × 10 ⁷ , and almost no deterioration in performance due to heat treatment was observed.

Example 7
11.5 mg of di-n-butyldithienobenzodifuran synthesized in Example 2 and 563 mg of toluene (Pure Grade manufactured by Wako Pure Chemical Industries, Ltd.) were added, dissolved by heating at 50 ° C., and then allowed to cool to room temperature (25 ° C.). Then, a solution for forming a drop cast organic semiconductor layer was prepared. The solution state is maintained even after 10 hours at 25 ° C. (the concentration of di-n-butyldithienobenzodifuran is 2.0% by weight), and it is confirmed that the compound is suitable for film formation by drop casting and ink jet. did.

Then, a 63 nm-thick organic semiconductor layer of di-n-butyldithienobenzodifuran was produced by the same method as in Example 6, and a bottom gate-top contact type p-type organic thin film transistor was further produced. The hole carrier mobility was 0.53 cm ² / V · s, and the current on / off ratio was 1.1 × 10 ⁸ .

Furthermore, the electrical properties of the organic thin film transistor after annealing at 130 ° C. for 15 minutes were measured. The hole carrier mobility was 0.50 cm ² / V · s, the current on / off ratio was 7.8 × 10 ⁷ , and almost no deterioration in performance due to heat treatment was observed.

Example 8
Add 10.3 mg of bis {5- (n-pentyl) -2-furyl} dithienobenzodifuran synthesized in Example 5 and 1.02 g of toluene (pure grade manufactured by Wako Pure Chemical Industries, Ltd.), and heat to 50 ° C. After dissolution, the solution was allowed to cool to room temperature (25 ° C.) to prepare a solution for forming a drop cast organic semiconductor layer. The solution state is maintained after 10 hours at 25 ° C. (the concentration of bis {5- (n-pentyl) -2-furyl} dithienobenzodifuran is 1.0% by weight). It was confirmed that the compound was suitable for the membrane.

Then, an organic semiconductor layer of bis {5- (n-pentyl) -2-furyl} dithienobenzodifuran having a film thickness of 42 nm is prepared in the same manner as in Example 6, and further a bottom gate-top contact type. A p-type organic thin film transistor was produced. The hole carrier mobility was 0.95 cm ² / V · s, and the current on / off ratio was 7.9 × 10 ⁷ .

Furthermore, the electrical properties of the organic thin film transistor after annealing at 130 ° C. for 15 minutes were measured. The hole carrier mobility was 0.88 cm ² / V · s, the current on / off ratio was 5.8 × 10 ⁷ , and almost no deterioration in performance due to heat treatment was observed.

Comparative Example 1 (Di-n-octylbenzothienobenzothiophene)
Di n-octylbenzothienobenzothiophene was synthesized as follows according to the method described in the republished patent WO2008 / 047896.

In a 100 ml Schlenk reaction vessel, 2,7-di (1-octynyl) [1] benzothieno [3,2-b] [1] benzothiophene 286 mg (0.626 mmol), 10% Pd / C (manufactured by Wako Pure Chemical Industries, Ltd.) 62 mg and 10 ml of toluene (dehydration grade manufactured by Wako Pure Chemical Industries) were added. A hydrogen balloon was attached, and pressure reduction-hydrogen replacement with an aspirator was repeated three times, followed by stirring at room temperature for 10 hours. The solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (hexane) and recrystallized and purified twice from hexane (pure grade manufactured by Wako Pure Chemical Industries, Ltd.). White solid of di-n-octylbenzothienobenzothiophene 227 mg was obtained (yield 78%).
MS m / z: 464 (M ^<+> , 100%).

  12.1 mg of the obtained di-n-octylbenzothienobenzothiophene and 0.801 g of toluene (pure grade manufactured by Wako Pure Chemical Industries, Ltd.) were added, dissolved by heating at 50 ° C., and then allowed to cool to room temperature (25 ° C.). A solution for forming a drop cast organic semiconductor layer was prepared. The solution state was maintained even after 10 hours at 25 ° C. (di-n-octylbenzothienobenzothiophene concentration was 1.5% by weight), and it was confirmed that the compound was suitable for film formation by drop casting and ink jet. .

Then, an organic semiconductor layer of di-n-octylbenzothienobenzothiophene having a film thickness of 51 nm was produced by the same method as in Example 1, and a bottom gate-top contact p-type organic thin film transistor was further produced. The hole carrier mobility was 0.167 cm ² / V · s, and the current on / off ratio was 1.3 × 10 ⁶ .

  Furthermore, the electrical properties of the organic thin film transistor after annealing at 130 ° C. for 15 minutes were measured. However, the transistor operation cannot be obtained, and the material is inferior in heat resistance.

Comparative Example 2 (6,13-bis ((triisopropylsilyl) ethynyl) pentacene)
11.8 mg of 6,13-bis ((triisopropylsilyl) ethynyl) pentacene (manufactured by Sigma-Aldrich) and 0.775 g of toluene (pure grade manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the mixture was heated and dissolved at 50 ° C. at room temperature ( 25 ° C.) to prepare a drop cast organic semiconductor layer forming solution. A compound that is maintained in solution even after 10 hours at 25 ° C. (the concentration of 6,13-bis ((triisopropylsilyl) ethynyl) pentacene is 1.5% by weight), and is suitable for film formation by drop casting or ink jet. It was confirmed that.

Then, an organic semiconductor layer of 6,13-bis ((triisopropylsilyl) ethynyl) pentacene having a film thickness of 60 nm is manufactured in the same manner as in Example 1, and a bottom gate-top contact type p-type organic thin film transistor is formed. Produced. The hole carrier mobility was 0.0524 cm ² / V · s, and the current on / off ratio was 1.2 × 10 ⁵ .

  The novel benzodifuran derivative of the present invention can be expected to be applied as a semiconductor device material typified by an organic thin film transistor because it provides high carrier mobility and is excellent in solubility in a solvent and heat resistance of a transistor element.

; It is a figure which shows the structure by the cross-sectional shape of an organic thin-film transistor.

(A): Bottom gate-top contact organic thin film transistor (B): Bottom gate-bottom contact organic thin film transistor (C): Top gate-top contact organic thin film transistor (D): Top gate-bottom contact organic thin film transistor 1: Organic semiconductor layer 2: Substrate 3: Gate electrode 4: Gate insulating layer 5: Source electrode 6: Drain electrode

Claims (5)

A benzodifuran derivative represented by the following general formula (1):

(Wherein the substituents R ¹ and R ² are the same or different and are hydrogen, methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, n-hexyl, n- A heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-dodecyl group, 2-ethylhexyl group, cyclohexyl group, or cyclooctyl group having 1 to 12 carbon atoms, 2-furyl group 5-fluoro-2-furyl group, 5-methyl-2-furyl group, 5-ethyl-2-furyl group, 5- (n-propyl) -2-furyl group, 5- (n-butyl) -2 -Furyl group, 5- (n-pentyl) -2-furyl group, 5- (n-hexyl) -2-furyl group, 5- (n-octyl) -2-furyl group, 5- (2-ethylhexyl) 2-furyl group, 2-thienyl group, 5-fluoro 2-thienyl group, 5-methyl-2-thienyl group, 5-ethyl-2-thienyl group, 5- (n-propyl) -2-thienyl group, 5- (n-butyl) -2-thienyl group, 5- (n-pentyl) -2-thienyl group, 5- (n-hexyl) -2-thienyl group, 5- (n-octyl) -2-thienyl group, 5- (2-ethylhexyl) -2-thienyl group Aryl group having 4 to 14 carbon atoms, which is a group, phenyl group, p-tolyl group, p- (n-hexyl) phenyl group, p- (n-octyl) phenyl group, or p- (2-ethylhexyl) phenyl group , an alkynyl group having 2 to 14 carbon atoms, or indicates an alkenyl group having a carbon number of 2 to 14, ^{T 1} and ^{T 2} represents a sulfur.) The benzodifuran derivative according to claim ^1, wherein the substituents R ¹ and R ² are the same or different and are an alkyl group having 1 to 12 carbon atoms or an aryl group having 4 to 14 carbon atoms. A solution for forming an organic semiconductor layer comprising the benzodifuran derivative according to claim 1 or 2 and a solvent. It forms with the solution for organic-semiconductor-layer formation of Claim 3 , The manufacturing method of the organic-semiconductor layer characterized by the above-mentioned. A method for producing an organic thin film transistor, comprising: an organic semiconductor layer according to claim 4 , wherein a source electrode and a drain electrode are provided on a substrate; and the gate electrode is laminated via an insulating layer.

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