JP5929109B2 - Novel ethynylbenzophenone compounds or analogs thereof - Google Patents

Description

  The present invention relates to novel ethynylbenzophenone compounds or analogs thereof that exhibit a non-linear light absorption effect.

  In recent years, a high-intensity pulse laser (for example, wavelength 400 to 410 nm, output 1 to 100 W, pulse width 1 to 10 psec, frequency 0.1 to 10 GHz) is focused and irradiated to a recording layer of an optical information recording medium such as a so-called optical disk. Thus, a technique has been proposed in which an area near the focal point is an optically heterogeneous area (area that functions as a recording mark) with respect to the surrounding area (Patent Document 1). In such a technique, in order to cope with the increase in recording capacity required for the optical information recording medium in recent years, it is required to shorten the recording mark formation time, that is, to shorten the information writing time to the optical information recording medium. In the technique of Patent Document 1, the writing speed is increased by adding an acid generator to the recording layer.

JP 2010-15632 A

  However, in the case of the optical information recording medium proposed in Patent Document 1, since the photoacid generator is highly photothermally sensitive, it can be stored in a high temperature environment (about 40 to 60 ° C.) that can occur in a general house or warehouse in the summer. Occasionally, an unintended acid is generated from the photoacid generator contained in the recording layer, which causes the optical information recording medium to gradually discolor, and there is a concern that the recording mark may disappear in a span of several decades. Has been.

  For this reason, it is stable in a high temperature environment that can occur in ordinary houses and warehouses, instead of a material having a problem of long-term storage such as a photoacid generator, but is preferable nonlinear light when irradiated with a high-intensity pulsed laser. There has been a demand for a compound that exhibits an absorption effect and can reduce the writing time.

  An object of the present invention is to solve the above-described conventional problems, and in order to shorten a writing time when writing a recording mark on a recording layer of an optical information recording medium with a high-intensity pulse laser. It is to provide a novel compound that exhibits a non-linear light absorption effect for addition to a layer.

  The present inventors have found that the above object can be achieved by ethynylbenzophenone compounds having a specific benzophenone structure (benzophenone structure, thiobenzophenone structure or benzophenone imine structure) or analogs thereof, and have completed the present invention. It was.

  That is, the present invention is an ethynylbenzophenone compound represented by the formula (1) or an analog thereof.

In Formula (1), R ₁ is a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an aralkyl group, n is 1, 2 or 3, X is O, S or NH, and Ar is A phenyl group, a biphenylyl group or a hydroxydiphenylmethyl group. However, when Ar is a phenyl group and X is O, R ₁ is not a hydrogen atom, and when n is 1, it is not a fluorine atom bonded to the 4′-position of the phenyl group to which R ₁ is bonded.

  The present invention also provides a method for producing an ethynylbenzophenone compound of the formula (1) or an analogue thereof, wherein the terminal alkyne of the formula (2) is converted to a halogen of the formula (3) under Sonogashira coupling reaction conditions. There is provided a process for producing an ethynylbenzophenone compound of the formula (1) or an analog thereof by reacting with an aryl halide.

In these formulas, R ₁ is a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an aralkyl group, n is 1, 2 or 3, X is O, S or NH, and Y is a bromine atom or It is an iodine atom, and Ar is a phenyl group, a biphenylyl group or a hydroxydiphenylmethyl group. However, when Ar is a phenyl group and X is O, R ₁ is not a hydrogen atom, and when n is 1, it is not a fluorine atom bonded to the 4′-position of the phenyl group to which R ₁ is bonded.

  The novel ethynyl benzophenone compounds or analogs thereof of the present invention have a specific benzophenone structure, that is, a benzophenone structure, a thiobenzophenone structure or a benzophenone imine structure, in which acetylene is directly bonded, and acetylene has a specific aryl group or aralkyl group. It has a special chemical structure in which is bound, and exhibits a nonlinear light absorption effect. Therefore, when writing a recording mark on the recording layer of an optical information recording medium with a high-intensity pulsed laser, if the recording layer contains the ethynylbenzophenone compound of the present invention or an analog thereof, the writing time is greatly reduced. Can be

1A is a ¹ H-NMR chart of an ethynylbenzophenone compound of the formula (1a) in Example 1. FIG. FIG. 1B is a partially enlarged chart of FIG. 1A. 2A is a ¹ H- NMR chart of an ethynylbenzophenone compound of the formula (1b) in Example 2. FIG. FIG. 2B is a partially enlarged chart of FIG. 2A.

  The novel compound of the present invention is an ethynylbenzophenone compound of the following formula (1) or an analog thereof.

In formula (1), examples of the halogen atom for R ₁ include a fluorine atom, a chlorine atom, and a bromine atom. Among these, a fluorine atom is preferable from the viewpoint of ease of production.

Examples of the alkyl group for R ₁ include a methyl group, an ethyl group, a propyl group, and a butyl group. These alkyl groups can have a substituent such as a chlorine atom, a bromine atom, a nitro group, or a hydroxy group. Of these, a butyl group is preferable from the viewpoint of solubility in monomers.

Examples of the aryl group for R ₁ include a phenyl group, a biphenyl-4-yl group, a naphthyl group, and a fluoren-2-yl group. These aryl groups can have a substituent such as a chlorine atom, a bromine atom, a nitro group, or a hydroxy group. Among these, a phenyl group is preferable from the viewpoint of ease of production.

Examples of the aralkyl group for R ₁ include a benzyl group, an o-methylbenzyl group, a (1-naphthyl) methyl group, a 2-pyridylmethyl group, and a 9-anthracenylmethyl group. These aralkyl groups can have a substituent such as a chlorine atom, a bromine atom, a nitro group, or a hydroxy group. Among these, a benzyl group is preferable from the viewpoint of ease of production.

Among these R _1, a hydrogen atom is preferable from the viewpoint of availability of raw materials.

Further, n as the number of R ₁ is 1, 2 or 3, but when R ₁ is a hydrogen atom, there is no difference in chemical structure depending on the number of n. When R ₁ is a substituent other than a hydrogen atom and n is 1, the bonding position of R _{1 to} the phenyl group not directly bonded to the ethynyl group is the 2′-position, the 3′-position, or the 4′-position. In view of ease of production, the substitution position is preferably the 4 'position. The combinations of substitution positions when n is 2 are (2'-position, 4'-position), (2'-position, 6'-position), (3'-position, 5'-position), (2'-position, 5'-position). Rank). Among these, (2'-position, 4'-position) is preferable from the viewpoint of ease of production. The combinations of substitution positions when n is 3 are (2'-position, 4'-position, 6'-position), (2'-position, 4'-position, 5'-position), (2'-position, 3'-position, 4 ').

  X is O, S or NH, and among them, O is preferable from the viewpoint of availability of raw materials.

Examples of Ar include a phenyl group, a biphenylyl group, and a hydroxydiphenylmethyl group. Among these, a biphenyl-4-yl group and a hydroxydiphenylmethyl group are preferable from the viewpoint of the performance of the optical disk. However, when Ar is a phenyl group and X is O, R ₁ is not a hydrogen atom, and when n is 1, it is not a fluorine atom bonded to the 4′-position of the phenyl group to which R ₁ is bonded.

  Preferred specific embodiments of the novel ethynylbenzophenone compounds of the present invention (1) or analogs thereof described above are the compounds represented by the following formulas (1a) and (1b).

  Of the compounds of the formulas (1a) and (1b), the latter is more preferable in terms of solubility in monomers and the like.

  The novel ethynylbenzophenone compounds of the formula (1) or their analogs according to the present invention can be used for Sonogashira coupling reactions (see, for example, Tetrahedron Lett. 1975, 4467; J. Org. Chem. 2001, 66, 1910-1913). Can be produced according to the following reaction formula.

  Specifically, the terminal alkyne of formula (2) is reacted with an aryl halide of formula (3) under known Sonogashira coupling reaction conditions to provide an ethynylbenzophenone compound of formula (1) or an analog thereof. The body can be manufactured.

In these formulas, R ₁ , n, X, Y, and Ar are as described for formula (1) or formula (3).

  The Sonogashira coupling reaction is a chemical reaction in which arylalkynes and aryl halides are cross-coupled by the action of a palladium catalyst, a copper catalyst, and a base to obtain an alkynylated aryl (aromatic acetylene). is there. The general operation of this reaction is as follows.

  That is, an approximately equimolar mixture of the terminal alkyne of the formula (2) and the aryl halide of the formula (3) is mixed with 1/10 mol of copper (I) iodide, palladium (II) dichlorobistriphenylphosphine, triethylamine, etc. A novel ethynylbenzophenone compound of the formula (1) is obtained as a product by mixing with a basic solvent, adding triphenylphosphine as necessary, and heating in a nitrogen atmosphere at room temperature or under reflux for 1 to 12 hours. Alternatively, an analog thereof can be obtained. If necessary, known purification methods can be applied to obtain highly pure ethynylbenzophenone compounds of the formula (1) or analogs thereof.

  The ethynylbenzophenone compounds of the formula (1) of the present invention described above or analogs thereof can be preferably blended as a sensitizer in the recording layer of an optical information recording medium on which recording is performed by laser ablation with a high intensity pulse laser. it can. As such an optical information recording medium, a medium in which a recording layer is formed between transparent substrates such as glass and polycarbonate can be preferably exemplified.

  As such a recording layer, a thermosetting epoxy compound having a high planar skeleton capable of realizing a high crosslinking density, an ethynylbenzophenone compound of the formula (1) of the present invention or an analog thereof, an epoxy curing agent, A cured resin layer obtained by curing a thermosetting epoxy composition containing s is preferably applied.

  The optical information recording medium can be produced by applying a thermosetting epoxy composition to a transparent substrate by a conventional method, and overlaying the transparent substrate thereon, followed by heat curing in an oven.

  Hereinafter, the present invention will be specifically described by way of examples.

<Example 1>
Three-necked flask 100mL purged with nitrogen, 4-bromo benzophenone 2.33 g, 4-ethynyl biphenyl 1.59 g, triphenylphosphine 0.025 g, bis (triphenylphosphine) palladium (II) dichloride Li de 0.0125 g, 0.0125 g of CuI (I) and 40 mL of triethylamine were added, heated to reflux for 4 hours, and then stirred at room temperature for 16 hours. After completion of the reaction, the reaction mixture was neutralized with 5% aqueous hydrochloric acid, and the resulting precipitate was collected by filtration and recrystallized from toluene to obtain 2.1 g (yield 65%) of white crystals. The white crystals were identified by ¹ H-NMR (see FIGS. 1A and 1B) and MS, and the purity was 99% or more (LC, Area%). From the above analysis results, the white crystals could be identified as the compound of formula (1a).

¹ H-NMR (CDCl ₃ ): 7.36-7.38 (m, 1H), 7.42-7.51 (m, 4H), 7.50-7.65 (m, 9H), 7. 77-7.81 (m, 4H)

MS (m / z): 389 (M + H)

<Example 2>
Into a nitrogen-substituted 100 mL three-necked flask, 2.33 g of 4-bromobenzophenone, 1.86 g of 1,1-diphenyl-2-propyn-1-ol, 0.025 g of triphenylphosphine, bis (triphenylphosphine) palladium (II ) dichloride Li de 0.0125 g, CuI (I) 0.0125 g, and triethylamine 40mL was poured, after heated to reflux for 4 hours, was continued for 16 hours at room temperature. After completion of the reaction, the mixture was neutralized with 5% aqueous hydrochloric acid, the mixture was extracted with ethyl acetate, the organic layer was dried with anhydrous magnesium sulfate , the solvent was distilled off, and the residue was recrystallized with ethanol. 2.4 g (yield 69%) of white crystals was obtained. The white crystals were identified by ¹ H-NMR (see FIGS. 2A and 2B) and MS, and the purity was 99% or more (LC, Area%). From the above analysis results, the white crystals could be identified as the compound of formula (1b).

¹ H-NMR (CDCl ₃ ): δ (ppm) 2.91 (s, 1H), 7.28-7.38 (m, 6H), 7.45-7.50 (m, 2H), 7. 58-7.67 (m, 7H), 7.75-7.77 (m, 4H)

MS (m / z): 389 (M + H)

(Evaluation of writing time reduction effect)
<Creation of optical information recording media 1 to 9>
As an epoxy compound, (1,6-naphthodiol diglycidyl ether (HP-4032D, DIC Corporation)) and the compound of Example 1 or 2, benzophenone, diphenylacetylene and 1,4-diphenylbutadiyne are selected. The sensitizer is mixed in the blending amount shown in Table 1, and 1 part by mass of tris (dimethylaminomethyl) phenol (DMP-30, Kanto Chemical Co., Ltd.) is uniformly mixed as a curing agent for epoxy and defoamed. A liquid thermosetting composition was prepared by treatment, and this thermosetting composition was applied to a 0.15 mm thick cover glass substrate to a thickness of 0.30 mm, and then 0.0. A 75 mm thick glass substrate is placed and heated in an oven heated to 80 ° C. for 12 hours to cure the thermosetting composition to form a recording layer. To obtain an optical information recording medium having a sandwiched recording layer.

<Writing test evaluation>
Laser light from a laser diode (wavelength: 405 nm, pulse width: 3 picoseconds, objective out-peak power: 19 W, repetition frequency: 1 GHz) is emitted using an objective lens (NA: 0.85). A recording mark was formed by focusing light at a depth of 50 μm of the recording layer of the information recording media 1 to 9. At this time, writing was performed by forming a plurality of recording marks having different pulse laser light irradiation times (writing times). The adjustment of the writing time was controlled by a function generator (MP1800A, Anritsu Corporation).

  Next, the recording mark was read using the same laser diode. Specifically, the signal from the recording mark was branched from the deflecting beam splitter and the λ / 4 plate, and it was confirmed using a CCD (Charge Coupled Device) on the basis of whether or not the recording mark could be confirmed. The shortest irradiation time among the irradiation times of the pulse laser beam at the time of writing the record mark that was confirmed was set as the writing time of the optical information recording medium.

<Discussion of results in Table 1>
The optical information recording medium 5 is a medium having a recording layer containing no sensitizer, and has a relatively long writing time of 1100 ns. On the other hand, the optical information recording media 6 to 9 include a recording layer containing, as a sensitizer, a compound having an aromatic conjugated system that is expected to exhibit a nonlinear light absorption effect with respect to a laser beam having a chemical structure of 405 nm. It can be seen that the writing time is significantly shorter than that of the optical information recording medium 5.

  In addition, in the case of the optical information recording medium 4 containing the novel ethynylbenzophenone compounds of the present invention or analogs thereof (the compounding amount is the same as the optical information recording media 6 to 8), the writing time is further shortened. You can see that

  Further, in the case of the novel ethynylbenzophenone compounds of the present invention or analogs thereof, the results of the optical information recording media 1 and 2 to 4 realize the same writing time reduction effect as that of the optical information recording media 6 to 9. Therefore, it can be seen that a blend of about 1/10 is sufficient.

  In addition, when the optical information recording media 1 to 4 after optical information recording were left in an oven at 85 ° C. for 500 hours to read out the recording marks, there was no change from before, and good storage stability was obtained. Indicated.

  The novel ethynyl benzophenone compounds or analogs thereof of the present invention have acetylene directly bonded to a benzophenone structure, that is, a benzophenone structure, a thiobenzophenone structure, or a benzophenone imine structure, and further a specific aryl group or aralkyl group is bonded to acetylene. Because of its special chemical structure, it exhibits a nonlinear light absorption effect. Therefore, when writing a recording mark on the recording layer of an optical information recording medium with a high-intensity pulsed laser, if the recording layer contains the ethynylbenzophenone compound of the present invention or an analog thereof, the writing time is greatly reduced. Can be Therefore, it is useful as a sensitizer for blending into the recording layer of the optical information recording medium.

Claims (4)

Formula (1)

(In the formula (1), _{R 1} is water MotoHara child, n is 1, X is O, Ar is a biphenyl-4-yl group or a hydroxy diphenylmethyl group.)
Ethynyl benzophenone compounds represented in. The compound of the formula (1) is represented by the following formula (1a)

Ethynyl benzophenone compounds represented in. The compound of the formula (1) is represented by the following formula (1b)

Ethynyl benzophenone compounds represented in. A process for the preparation of ethynylbenzophenone compounds of formula (1) according to claim 1,
A terminal alkyne of the formula (2), in Sonogashira coupling reaction conditions, manufacturing method characterized by forming ethynyl benzophenone compounds of formula (1) by reaction with an aryl halide of formula (3) .

(In these formulas, _{R 1} is hydrogen atom, n is 1, X is O, Y is bromine atom or iodine atom, Ar is biphenyl-4-yl group or a hydroxymethyl diphenylmethyl Group.)

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