JP7047608B2 - Method for producing aromatic compounds - Google Patents

Description

The present invention relates to a method for producing an aromatic compound.

An organic thin film transistor (organic TFT) made of an organic material for a semiconductor layer does not require a high temperature heat treatment process for its manufacture, so that it can be mounted on a plastic substrate having poor heat resistance. Therefore, the use of these substrates is possible. It is expected to be applied to next-generation electronics (for example, flexible display devices and wearable devices) that are expected to be used. Among such organic materials, a compound having a [1] benzothiophene [3,2-b] [1] benzothiophene ring (hereinafter, [1] benzothiophene [3,2-b] [1] benzothiophene ring is used. BTBT (or BTBT ring), a compound having a BTBT ring (that is, a compound having a substituent on the BTBT ring) may be referred to as a BTBT derivative) or Zinaft [2,3-b: 2', 3'-f]. Compounds having a thieno [3,2-b] thiophene ring (hereinafter, ginaft [2,3-b: 2', 3'-f] thieno [3,2-b] thiophene ring is referred to as DNTT (or DNTT ring), A compound having a DNTT ring (that is, a compound having a substituent on the DNTT ring) may be referred to as a DNTT derivative) because its semiconductor properties (mobility) surpass those of amorphous silicon (Patent Document 1). And 2), in promoting the practical use of organic TFTs, a method for practically (industrialally) producing these BTBT derivatives (or DNTT derivatives) is desired.

In general, a BTBT derivative (or DNTT derivative) "constructs a BTBT ring (or DNTT ring) as a first stage (performs a BTBT ring (or DNTT ring) formation reaction)", and then "the BTBT ring" as a second stage. It is obtained by "introducing a desired substituent into the ring (or DNTT ring)" (note that when the BTBT ring (or DNTT ring) is constructed (formed) in the previous stage, the ring is provided in a form having a substituent in advance. It may be constructed (formed).) Here, the latter stage is a "substituent introduction reaction into an aromatic compound" performed by combining known and conventional synthetic reactions, whereas the first stage forms an aromatic ring (constructing an aromatic ring by a ring closure reaction). It has the peculiarity of). Therefore, in order to practically produce a BTBT derivative (or DNTT derivative), it is necessary to provide a practical "method for constructing (forming) a BTBT ring (or DNTT ring)" as a first step.

Patent Documents 3 to 7, 11, 12 and 15, and Non-Patent Documents 1 to 4, 8 to 10, 12 to 15, and 22 disclose a method for forming a BTBT ring by a ring closure reaction. Common to these reactions is that the BTBT ring, which is the target compound (product), has two sulfur atoms, whereas the starting compound (reactant), which is the substrate, is sulfur. In the reactions disclosed in Patent Documents 3-7 and 15 and Non-Patent Documents 1-4, 12-15, and 22 that carry less than two atoms, the reactants do not contain sulfur atoms. In the reactions disclosed in Patent Documents 11 and 12 and Non-Patent Documents 8-10, the reactants contain only one sulfur atom), so it is necessary to add a sulfur source substance separately. In general, such sulfur source substances need to be added in an amount larger than the amount of the substance determined by the chemical reaction formula in order to increase the reaction yield, and from the viewpoint of environmental friendliness and green chemistry, waste reduction can be achieved. Considering what is required, these reactions (reactions in which a sulfur source substance is added separately) are not preferable as an industrial production method.

Patent Documents 3 and 4 and Non-Patent Documents 1 and 2 describe a method for obtaining a BTBT ring (or DNTT ring) by reacting an o-chlorobenzaldehyde derivative with a sulfur compound such as a metal hydrosulfide. However, it is known that the o-chlorobenzaldehyde derivative gives a polymer by-product by reacting with a metal hydrosulfide or the like (Non-Patent Document 2). Polymer by-products, which are concerned about poor solubility, may cause adhesion to reaction vessels and clogging of pipes, and easily remain as impurities, which is essential for organic semiconductors to achieve high purity. Not preferred. In view of the above, these reactions are not preferable as an industrial production method.

Patent Document 5 describes a method for obtaining a BTBT ring (or DNTT ring) by reacting a benzaldehyde derivative with a halogenating agent and a sulfur compound. However, a halogenating agent such as thionyl chloride decomposes in air to generate highly toxic hydrogen chloride gas, sulfite gas, etc., so that it is difficult to handle, and the reaction carried out at a high temperature is the halogenating agent. Promotes decomposition. In view of the above, the reaction is not preferable as an industrial production method.

Patent Documents 6 and 7 and Non-Patent Documents 3 and 4 describe a method for obtaining a BTBT ring by reacting benzyl chloride, α, α-dichlorotoluene or α, α, α-trichlorotoluene with elemental sulfur. There is. However, these reactions require heating at a high temperature of 200 ° C. or higher for 10 hours or longer, resulting in high production cost. Further, according to Patent Documents 6 and 7, the reaction is accompanied by the generation of corrosive and irritating hydrogen chloride gas and sulfur chloride gas during the reaction. In view of the above, these reactions are not preferable as an industrial production method. In the comparative example described later, when a reproduction experiment was carried out, when α, α-dichlorotoluene was used, BTBT was not produced at 230 ° C. for 3 hours, and a small amount of BTBT was produced at 260 ° C. for 3 hours (). It was actually confirmed that the reaction required a high temperature of 200 ° C. or higher). In addition, the generation of acid gas was also confirmed in the reproduction experiment.

Patent Documents 8 and 9 and Non-Patent Documents 5 to 7 describe a method for obtaining a BTBT ring by intramolecularly condensing a 3- (phenylthio) benzo [b] thiophene derivative using a transition metal catalyst. There is. However, since an expensive transition metal catalyst is used, the production cost is high. Furthermore, it is stated that the reaction is carried out under nitrogen, and such restrictions also lead to an increase in cost. In view of the above, these reactions are not preferable as an industrial production method.

Patent Document 10 describes a method for obtaining a BTBT ring by intramolecularly condensing a 2- [2- (methylsulfinyl) phenyl] benzo [b] thiophene derivative using a strong acid as a solvent. However, since a large amount of strong acid is used, it is necessary to treat these acid waste liquids, and therefore, the reaction is not preferable as an industrial production method.

In Patent Document 11 and Non-Patent Document 8, butyllithium is allowed to act on a 3-bromo-2- (2-bromophenyl) benzo [b] thiophene derivative, and then bis (phenylsulfonyl) sulfide is allowed to act on the molecule. A method for obtaining a BTBT ring by intramolecular condensation is described. However, butyllithium is difficult to handle because it reacts with moisture in the air and ignites, and therefore these reactions are industrially unfavorable.

Patent Document 12 and Non-Patent Documents 9 and 10 describe a method for obtaining a BTBT ring by allowing a sulfur compound to act on an iodonium salt derivative. However, since it is necessary to carry out the reaction under an inert gas in order to improve the yield, it leads to high cost, and therefore these reactions are not preferable as an industrial production method.

Patent Documents 13, 14, 17 and 18 and Non-Patent Documents 11, 18, 19 and 21 describe methods for cyclizing a stilbene derivative to obtain a BTBT ring. However, these reactions use hydrogen iodide, bromine or iodine as additives, which are irritating and difficult to handle. Therefore, these reactions are not preferable as an industrial production method.

Patent Document 16 describes a method for obtaining a BTBT ring by allowing an elemental iodine to act on a bis [2- (methylthio) phenyl] acetylene derivative in an amount of 20 equivalents to cause an intramolecular condensation. However, as mentioned above, iodine is irritating and difficult to handle. Further, when a large amount of added iodine is quenched, the sulfur simple substance generated by the reaction between sodium thiosulfate, which is a quenching agent, and iodine becomes an emulsion, which complicates the liquid separation operation. Therefore, the reaction is not preferable as an industrial production method.

Non-Patent Document 17 describes a method for obtaining a BTBT derivative by thermally decomposing a phosphorus ilide derivative at 850 ° C. However, since it requires a high temperature of 850 ° C., it cannot be said to be a practical manufacturing method.

Non-Patent Document 20 describes a method for obtaining a BTBT ring by allowing a base such as KOtBu to act on a dithiocarbamic acid derivative. However, metal alkoxides such as KOtBu have the property of absorbing moisture and igniting, and are difficult to handle. According to Non-Patent Document 20, the reaction takes a long time. In view of the above, the reaction is not preferable as an industrial production method.

Non-Patent Document 22 describes a method for obtaining a BTBT ring by allowing diphenylethanedione to act on diphosphorus pentasulfide. However, the yield is as low as 3.9%, which is not a practical production method.

Patent Document 19 describes a method for obtaining a BTBT ring by allowing a base such as KOtBu to act on a stilbene derivative or a diphenylacetylene derivative. However, metal alkoxides such as KOtBu have the property of absorbing moisture and igniting, and are difficult to handle. Therefore, the reaction is not preferable as an industrial production method.

International Publication No. 2012/121393 International Publication No. 2012/115236 Japanese Unexamined Patent Publication No. 2010-275192 JP-A-2015-030727 Japanese Unexamined Patent Publication No. 2008-290963 U.S. Pat. No. 3,278,552 U.S. Pat. No. 3,433,874 International Publication No. 2014/030700 Japanese Unexamined Patent Publication No. 2016-193868 Japanese Unexamined Patent Publication No. 2011-256144 Japanese Unexamined Patent Publication No. 2011-184309 China Publication No. 105820098 International Publication No. 2015/028768 Japanese Unexamined Patent Publication No. 2009-062302 Japanese Unexamined Patent Publication No. 2010-20523 Japanese Unexamined Patent Publication No. 2009-196975 Japanese Unexamined Patent Publication No. 2009-07780 International Publication No. 2009/11359 US Publication No. 2017/0117484

Journal of Materials Chemistry C, 2016, Vol. 4, pp. 6742 Tetrahedron Letters, 2011, Vol. 52, p. 285 Collection of Czechoslovak Chemical Communications, 2002, Vol. 67, p. 645. Journal of the American Chemical Society, 2012, Vol. 134, p. 16548 Tetrahedron Letters, 2014, Vol. 55, p. 4175 Journal of the American Chemical Society, 2013, Vol. 135, p. 13900 Angewandte Chemie International Edition, 2015, Vol. 54, p. 5772 Tetrahedron, 2016, Vol. 72, p. 8085 Chemical Communications, 2017, Vol. 53, p. 2918 Organic Letters, 2016, Vol. 18, p. 5756 Zhurnal Organicheskoi Kimii, 1980, Vol. 16, p. 425 European Journal of Organic Chemistry, 2011, p. 7331 Journal of Heterocyclic Chemistry, 1998, Vol. 35, p. 725 Journal of Materials Chemistry C, 2016, Vol. 4, p. 5981 Tetrahedron Letters, 2010, Vol. 51, p. 5277 Collection of Czechoslovac Chemical Communications, 2009, Vol. 74, p. 785. Synlett, 1995, p. 53 Zhurnal Organicheskoi Kimii, 1980, Vol. 16, p. 430 Journal of Organic Chemistry, 1993, Vol. 58, p. 5209 Angewandte Chemie, International Edition, 2010, Vol. 49, p. 4751 Journal of Organic Chemistry, 2013, Vol. 78, p. 7741 Phosphorus, Sulfur and Silicon, 2002, 177, p. 2725

As described above, the known and commonly used BTBT ring (or DNT ring) manufacturing method has problems in terms of an industrial manufacturing method. Therefore, an object of the present invention is to provide a method for producing a BTBT derivative (or DNTT derivative) in which the above-mentioned problems are solved. Specifically, the reaction proceeds at low temperature (200 ° C or less) in the atmosphere without adding a sulfur source substance separately and without using corrosive, irritating, toxic, or ignitable raw materials. It is an object of the present invention to provide a method for constructing a BTBT ring (or DNT ring), and thus to provide a method for producing a BTBT derivative (or DNT T derivative).

The present inventors have conducted diligent studies, and by using the compound represented by the general formula (2) as a starting compound (reactant), a BTBT ring (or DNT ring) is formed, which is represented by the general formula (1). We have found that a BTBT derivative (or DNTT derivative) can be obtained, and have completed the present invention.

（１）

(1)

（２）

(2)

(In each formula, m represents 0 or 1, and R ¹ is a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a cyano group, a nitro group, a carbonyl group, an alkyl group having 1 to 20 carbon atoms, and a carbon atom number. Represents an alkoxy group from 1 to 20, an alkylsulfanyl group having 1 to 20 carbon atoms, or an aryl group (R ¹ may be the same or different), and X represents a halogen atom (X represents a halogen atom). They may be the same or different.).).

According to the present invention, a BTBT derivative (or DNTT derivative) can be produced by a low temperature of 200 ° C. or lower and an atmospheric reaction without the addition of a sulfur source substance. Therefore, it is possible to provide a method for producing a BTBT derivative (or DNTT derivative) that is compatible with green chemistry.

Hereinafter, the production method of the present invention will be described. The manufacturing scheme of the present invention is as follows.

（Ｓ１）
（ただし、Ｒ^１、ｍ、Ｘは前記と同義。）

(S1)
(However, ^R1 , m, and X are synonymous with the above.)

(About R ¹ )
In the general formulas (1) and (2), R ¹ is a hydrogen atom, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), a hydroxyl group, an amino group, a cyano group, a nitro group, a carbonyl group, and a carbon atom. Alkyl groups of numbers 1 to 20, alkoxy groups of 1 to 20 carbon atoms, alkylsulfanyl groups of 1 to 20 carbon atoms, or aryl groups, and the plurality of R1s may be the same or different from ^each other. good.

Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a neopentyl group and an n-hexyl. Group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, 1-methylhexyl group, cyclohexylmethyl group, n-octyl group, tert-octyl group, 1-methylheptyl group, 2-ethylhexyl group, 2-propylpentyl group, n-nonyl group, 2,2-dimethylheptyl group, 2,6-dimethyl-4-heptyl group, 3,5 5-trimethylhexyl group, n-decyl group, n-undecyl group, 1-methyldecyl group, n-dodecyl group, n-tridecyl group, 1-hexylheptyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group. Groups, n-heptadecyl group, n-octadecyl group, n-eicosyl group and the like can be mentioned (these are examples, and the alkyl group having 1 to 20 carbon atoms is not limited thereto. In addition, they may be substituted with halogen atoms (eg, trifluoromethyl group, etc.). In the present invention, the alkyl group may be a cycloalkyl group, a cycloalkylalkyl group, or an alkylcycloalkyl group.

Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, an n-pentyloxy group and an isopentyloxy group. Neopentyloxy group, n-hexyloxy group, 1-methylpentyloxy group, 4-methyl-2-pentyloxy group, 3,3-dimethylbutyloxy group, 2-ethylbutyloxy group, n-heptyloxy group, 1-Methylhexyloxy group, Cyclohexylmethyloxy group, n-octyloxy group, tert-octyloxy group, 1-methylheptyloxy group, 2-ethylhexyloxy group, 2-propylpentyloxy group, n-nonyloxy group, 2 , 2-Dimethylheptyloxy group, 2,6-dimethyl-4-heptyloxy group, 3,5,5-trimethylhexyloxy group, n-decyloxy group, n-undecyloxy group, 1-methyldecyloxy group, n-dodecyloxy group, n-tridecyloxy group, 1-hexylheptyloxy group, n-tetradecyloxy group, n-pentadecyloxy group, n-hexadecyloxy group, n-heptadecyloxy group, n- Examples thereof include an octadecyloxy group and an n-eicosyloxy group (these are examples, and the alkoxy group having 1 to 20 carbon atoms is not limited thereto). In the present invention, the alkoxy group may be a cycloalkyloxy group, a cycloalkylalkyloxy group, or an alkylcycloalkyloxy group.

Examples of the alkylsulfanyl group having 1 to 20 carbon atoms include methylsulfanyl group, ethylsulfanyl group, n-propylsulfanyl group, isopropylsulfanyl group, n-butylsulfanyl group, isobutylsulfanyl group, n-pentylsulfanyl group and iso. Pentylsulfanyl group, neopentylsulfanyl group, n-hexylsulfanyl group, 1-methylpentylsulfanyl group, 4-methyl-2-pentylsulfanyl group, 3,3-dimethylbutylsulfanyl group, 2-ethylbutylsulfanyl group, n- Heptylsulfanyl group, 1-methylhexylsulfanyl group, cyclohexylmethylsulfanyl group, n-octylsulfanyl group, tert-octylsulfanyl group, 1-methylheptylsulfanyl group, 2-ethylhexylsulfanyl group, 2-propylpentylsulfanyl group, n- Nonylsulfanyl group, 2,2-dimethylheptylsulfanyl group, 2,6-dimethyl-4-heptylsulfanyl group, 3,5,5-trimethylhexylsulfanyl group, n-decylsulfanyl group, n-undecylsulfanyl group, 1 -Methyldecylsulfanyl group, n-dodecylsulfanyl group, n-tridecylsulfanyl group, 1-hexylheptylsulfanyl group, n-tetradecylsulfanyl group, n-pentadecylsulfanyl group, n-hexadecylsulfanyl group, n-hepta Examples thereof include a decylsulfanyl group, an n-octadecylsulfanyl group, an n-eicosylsulfanyl group, and the like (these are examples, and the alkylsulfanyl group having 1 to 20 carbon atoms is not limited thereto. not.). In the present invention, the alkylsulfanil group may be a cycloalkylsulfanil group, a cycloalkylalkylsulfanil group, or an alkylcycloalkylsulfanil group.

The aryl group is not particularly limited as long as it is an aromatic group (aromatic hydrocarbon group or heteroaromatic group) which may have an alkyl group or a halogen atom (halogeno group) as a substituent. for example,
From a phenyl group, a naphthyl group, an azulenyl group, an anthrasenyl group, a phenanthrenyl group, an acenaphthylenyl group, an acenaphthenyl group, a fluorenyl group, a naphthacenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a monovalent group derived from biphenyl, and p-terphenyl. Aromatic hydrocarbon groups such as derived monovalent groups and monovalent groups derived from p-quarterphenyl;
o-tolyl group, m-tolyl group, p-tolyl group, 2,4-xylyl group, 2,6-xylyl group, mesityl group, juryl group, 4-ethylphenyl group, 4-n-propylphenyl group, 4 -Isopropylphenyl group, 4-n-butylphenyl group, 4-n-pentylphenyl group, 4-n-hexylphenyl group, 4-n-decaphenyl group, 4-stearylphenyl group, 9,9-dihexylfluore An aromatic hydrocarbon group having an alkyl group as a substituent such as an nyl group;
An aromatic hydrocarbon group having a halogen atom as a substituent such as a 4-fluorophenyl group, a 2,6-difluorophenyl group, a 4-chlorophenyl group, a 2,3,4,5,6-perfluorophenyl group;

Complex aromatic groups such as pyrrolyl group, thienyl group, oxadiazolyl group, pyridyl group, benzothienyl group, benzoxazolyl group, benzothiazolyl group, monovalent group derived from dibenzothiophene;
Examples thereof include a heteroaromatic group having an alkyl group as a substituent such as a 2-methylthienyl group, a 2-butylthienyl group, and a 2-hexylthienyl group; and the like.

(About X)
In the general formula (2), the two Xs may be the same or different from each other, and each represents a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and preferably each of them is a fluorine atom. , Chlorine atom or bromine atom.

(Specific compound represented by the general formula (2))
Specific examples of the compound represented by the general formula (2) include, but are not limited to, the following compounds.

(Specific compound represented by the general formula (1))
Specific examples of the compound represented by the general formula (1) include, but are not limited to, the following compounds.

(Synthetic conditions of the present invention)
The reaction temperature in the reaction of the present invention is not particularly limited as long as it is the temperature at which the reaction proceeds, and is in the range of room temperature to 300 ° C., but is preferably 80 to 250 ° C. Below 80 ° C, the reaction is slow and impractical, and above 250 ° C, the product may decompose.

The reaction solvent may not be used, but it is preferably used from the viewpoint of stirring efficiency and reaction uniformity. As the reaction solvent, known and commonly used ones can be used.
Hydrocarbon solvents such as pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, octadecane, cyclohexane, methylcyclohexane, tetralin;
Halogen solvents such as dichloromethane, chloroform, dibromomethane, dichloroethane, dibromoethane, 1,1,2-trichloroethane, dichloropropane, dibromopropane;
Toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, n-butylbenzene, n-amylbenzene, n-hexylbenzene, decalin, chlorobenzene, o-dichlorobenzene, 1,2,4-trichlorobenzene, bromo Aromatic solvents such as benzene and bromonaphthalene;
Ketone solvents such as acetone, 2-butanone, methyl isobutyl ketone, cyclohexanone;

Ether-based solvents such as diethyl ether, tetrahydrofuran, diisopropyl ether, dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, tetramethylene glycol dimethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and diphenyl ether;
Ester solvents such as ethyl acetate, propyl acetate, butyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, propylene glycol methyl ether acetate;

Amide solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformaldehyde, N, N-dimethylacetamide;
Urea-based solvents such as 1,3-dimethyl-2-imidazolindinone, N, N'-dimethylpropylene urea;
Sulfoxide-based solvents such as dimethyl sulfoxide and sulfolane; and the like can be mentioned.

Among the above solvents, a solvent having a boiling point of 80 ° C. or higher is preferable, and in particular, from the viewpoint of reaction yield, polar solvents such as ether-based solvents, amide-based solvents and sulfoxide-based solvents, hydrocarbon-based solvents and aromatic solvents are used. Is preferable. In addition, the solvent can be used alone or in combination of two or more.

The reaction atmosphere is not particularly limited to the atmosphere, oxygen, nitrogen, argon, carbon dioxide and the like.

In the production method of the present invention, additives may be added in order to allow the reaction to proceed efficiently. To exemplify these,
Bicarbonates such as sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate;
Carbonates such as sodium carbonate, potassium carbonate, cesium carbonate;
Phosphates such as sodium phosphate, disodium phosphate, trisodium phosphate, potassium phosphate, calcium phosphate, diammonium phosphate;
Hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, etc.
Fluoride such as potassium fluoride, cesium fluoride, tetrabutylammonium fluoride;
Alkoxides such as sodium methoxide, sodium ethoxide, potassium tert-butoxide;
Trimethylamine, triethylamine, tributylamine, diisopropylethylamine, N-methylmorpholine, N-methylpyrrolidin, N-methylpiperidine, 1,8-diaza-bicyclo [5.4.0] undec-7-ene, 1,4-diaza -Primary amines such as bicyclo [2.2.2] octane;
Pyridine, picolin, ethyl pyridine, propyl pyridine, butyl pyridine, t-butyl pyridine, 2,3-dimethyl pyridine, 2,4-dimethyl pyridine, 2,5-dimethyl pyridine, 2,6-dimethyl pyridine, 3,5- Pyridine derivatives such as dimethylpyridine, 2-methyl-5-ethyl-pyridine, 2,6-diisopropylpyridine, 2,6-dit-butylpyridine; and the like can be mentioned.

Among the above additives, hydrogen carbonate, carbonate, and hydroxide salt are preferable from the viewpoint of improving the reaction yield.

The additive can be used alone or in combination of two or more, and the amount thereof is not particularly limited as long as a BTBT derivative (or DNTT derivative) can be obtained, and the reaction can be effectively promoted. With respect to the compound of the general formula (2), 0.2 to 60 mol is preferable, 0.4 to 30 mol is more preferable, and 1 to 12 mol is further preferable.

Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited to these Examples.

(High performance liquid chromatography measurement)
When confirming the existence of BTBT by high performance liquid chromatography (hereinafter, may be abbreviated as HPLC), HPLC manufactured by Shimadzu Corporation (device configuration is as follows: system controller: SCL-10ADVP, liquid transfer unit). : LC-10ADVP, column oven: CTO-10ASVP, autosampler: SIL-10ADVP, detector: SPD-M10AVP.) Was used. A Kinetex 5 μm column (stationary phase: C18, particle system: 5 μm, length: 100 mm, inner diameter: 4.6 mm) manufactured by Phenomenex was used as the column, and the flow velocity: 1.0 ml / min, eluent: acetonitrile / water /. Measurement was performed under the conditions of acetonitrile = 50/50/0 → 50/0/50 (linear gradient: 10 min), measurement time: 20 min, detection wavelength: 340 nm, column temperature: 40 ° C., and injection amount: 1 uL. The measurement solution was prepared by filtering (pore diameter: 0.22 um) a solution of the sample in tetrahydrofuran (without stabilizer) (0.1% by mass).
(Measurement of hydrogen ion index)
The hydrogen ion index (pH) was measured with Whatman's pH test paper 2600-100A.
(Yield of target compound BTBT)
The yield of the target compound BTBT was determined by "((Yield of actually obtained BTBT (amount of substance)) x 100) / (Theoretical yield (amount of substance))". Here, the theoretical yield (amount of substance) is the "amount of substance charged (amount of substance) of the starting compound" when o-chlorobenzyldisulfide is used as the starting compound (Example), and o-chlorobenzaldehyde is used as the starting compound. Or, when α, α-dichlorotoluene is used (reference example and comparative example), it is “amount of starting compound charged (amount of substance) × 0.5”. The latter is due to the theoretical production of 0.5 mol of BTBT from 1 mol of the starting compound.
(Synthesis Example 1: Method for synthesizing o-chlorobenzyl disulfide)
To a 300 mL three-necked flask, 50.0 g (310 mmol) of o-chlorobenzyl chloride, 73.4 g (296 mmol) of sodium thiosulfate pentahydrate, and 102 mL of dimethyl sulfoxide were added, and the mixture was stirred at 80 ° C. for 8 hours. The reaction solution was cooled to room temperature, 200 mL of water was added, and the precipitated solid was filtered. The obtained solid was washed with water and methanol to obtain 43.0 g (yield 87.9%) of white crystals of o-chlorobenzyl disulfide.
^{1 1} H NMR (400 MHz, CDCl ₃ ): δ7.40-7.33 (m, 2H), δ7.28-7.18 (m, 6H), δ3.79 (s, 4H).
(Example 1)
0.30 g (0.95 mmol) of o-chlorobenzyl disulfide, 70% (measured value is 73%. The same applies hereinafter) 0.073 g (0.95 mmol) of sodium hydrosulfide, 0.90 mL of dimethyl sulfoxide in a 10 mL two-necked flask. Was added, and the mixture was stirred at 180 ° C. for 2 hours under the atmosphere. The reaction solution was cooled to room temperature, 2 mL of methanol was added, and the precipitated solid was filtered. The obtained solid was washed with water and acetone to obtain 0.025 g (yield 11%) of pale yellow crystals of BTBT.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): 7.85-7.95 ppm (m, 4H), 7.39-7.50 ppm (m, 4H).

(Example 2)
The same operation as in Example 1 was carried out except that 0.16 g (1.9 mmol) of sodium hydrogen carbonate was used instead of 70% sodium hydrosulfide in Example 1, and 0.094 g (yield 41) of pale yellow crystals of BTBT was used. %) Was obtained.
(Example 3)
The same operation as in Example 1 was carried out except that 0.076 g (1.9 mmol) of sodium hydroxide was used instead of 70% sodium hydrosulfide in Example 1, and 0.074 g (yield 32) of pale yellow crystals of BTBT was used. %) Was obtained.

(Example 4)
The same operation as in Example 1 was carried out except that 0.11 g (1.9 mmol) of potassium hydroxide was used instead of 70% sodium hydrosulfide in Example 1, and 0.058 g of pale yellow crystals of BTBT (yield 25). %) Was obtained.
(Example 5)
Same as Example 1 except that 0.16 g (1.9 mmol) of sodium hydrogen carbonate was used instead of 70% sodium hydrosulfide, and 0.9 mL of N, N-dimethylacetamide was used instead of dimethyl sulfoxide. To obtain 0.068 g (yield 30%) of pale yellow crystals of BTBT.
(Reference example 1)
According to Patent Document 3, 0.35 g (2.5 mmol) of o-chlorobenzaldehyde, 0.39 g (5 mmol) of 70% sodium hydrosulfide, and 7 mL of N-methyl-2-pyrrolidone were added to a 50 mL two-necked flask, and the temperature was 180 ° C. Was stirred for 3 hours. The reaction solution was cooled to room temperature, added to 100 mL of a saturated aqueous solution of ammonium chloride, and the precipitated solid was filtered. The obtained solid was washed with water and acetone to obtain 0.11 g (yield 37%) of pale yellow crystals of BTBT.
(Comparative Example 1)

Same as Reference Example 1 except that the flask size was 10 mL and the charged amounts of 70% sodium hydrosulfide and N-methyl-2-pyrrolidone were 0.097 g (1.3 mmol) and 1.3 mL, respectively. Although the formation of BTBT was confirmed, it could not be isolated due to the small amount (substantial yield 0%).

(Comparative Example 2)
According to the method described in Example 7 of Patent Document 6, 1.25 g (7.8 mmol) of α, α-dichlorotoluene and 0.27 g (8.3 mmol) of sulfur were added to a 10 mL two-necked flask, and the temperature was 230 ° C., 3 Stirred for hours. When the reaction solution was cooled to room temperature and the obtained black solid was analyzed by HPLC, the formation of BTBT could not be confirmed. In addition, gas was generated during the reaction, and the water in which the gas was absorbed showed strong acidity (pH 1).
(Comparative Example 3)
According to the method described in Example 7 of Patent Document 6, 1.25 g (7.8 mmol) of α, α-dichlorotoluene and 0.27 g (8.3 mmol) of sulfur are added to a 10 mL two-necked flask, and the temperature is 260 ° C., 3 Stirred for hours. The reaction solution was cooled to room temperature, and the obtained black solid was purified by silica gel column chromatography (developing solvent: chloroform) to obtain 0.018 g (yield 1.9%) of pale yellow crystals of BTBT. In addition, gas was generated during the reaction, and the water in which the gas was absorbed showed strong acidity (pH 1).

Among the known BTBT ring forming reactions, control experiments for comparison were carried out for those using no corrosive, irritating, toxic or ignitable raw materials (Reference Examples 1, Comparative Examples 1 to 3).

For compounds using a benzyl chloride derivative as a starting compound (Patent Document 6, etc.), a high temperature of 200 ° C. or higher is required to obtain the target compound BTBT, and acid gas is generated during the reaction. (Comparative Examples 2 and 3).

For compounds starting from o-chlorobenzaldehyde (Patent Document 3, etc.), the target compound can be obtained by adding a substance that is a source of sulfur in an amount equal to or greater than the amount determined by the chemical reaction formula (reference). Example 1) When the amount of substance was less than or equal to the amount determined by the chemical reaction formula, the real yield was 0% (Comparative Example 1).

On the other hand, in the present invention, as shown in Examples, no sulfur source substance is added separately (in Example 5, neither the solvent nor the additive contains sulfur atoms), and the temperature is low in the atmosphere. The target compound BTBT can be obtained by a reaction (200 ° C. or lower).

The aromatic compound (BTBT derivative or DNTT derivative) obtained by the production method of the present invention can be used, for example, as a material for an organic semiconductor or a raw material for an organic semiconductor material.

Claims (1)

A method for producing a compound represented by the general formula (1).
A method for producing a compound represented by the general formula (1), which comprises using the compound represented by the general formula (2) as a raw material.

(1)

(2)
(In each formula, m represents 0 or 1, and R ¹ is a hydrogen atom, a halogen atom, a hydroxyl group, an amino group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms, and 1 to 20 carbon atoms. Represents an alkoxy group, an alkylsulfanyl group having 1 to 20 carbon atoms, or an aryl group ( ^R1 may be the same or different), and X represents a halogen atom (X is the same). It may or may not be different.).).