JP2008214613A - Cationic compound and method for producing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel coloring matter suitable for an optical information recording medium, which enables record regeneration by a laser light of the wavelength of at most 450 nm and shows excellent recording characteristics. <P>SOLUTION: The cationic compound is represented by formula (I). The novel cationic compound is useful as a coloring matter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a novel cationic compound useful as a dye and a method for producing the same.

  2. Description of the Related Art Conventionally, an optical information recording medium (optical disc) capable of recording information only once with a laser beam is known. This optical disk is also called a recordable CD (CD-R), and its typical structure is a recording layer made of an organic dye on a transparent disk-shaped substrate, a light reflecting layer made of a metal such as gold, and a resin. The protective layers are provided in a laminated state in this order. Information recording on this CD-R is performed by irradiating the CD-R with a near-infrared laser beam (usually a laser beam having a wavelength of around 780 nm), and the irradiated portion of the recording layer emits the light. Information is recorded by absorbing and locally raising the temperature, causing a physical or chemical change (for example, generation of pits) and changing its optical properties. On the other hand, reading (reproduction) of information is also usually performed by irradiating a laser beam having the same wavelength as the recording laser beam, and a portion (recording portion) where the optical characteristics of the recording layer have changed and a portion (not changed) ( Information is reproduced by detecting the difference in reflectance from the unrecorded portion.

  Recently, a network including image information communication such as the Internet and a high-definition TV are rapidly spreading. Also, HDTV (High Definition Television) is scheduled to be broadcast, and there is an increasing demand for a large-capacity recording medium for recording image information inexpensively and easily. Although the DVD-R is secured to a certain extent as a large-capacity recording medium, it cannot be said that the DVD-R has a large enough recording capacity to meet future requirements. Therefore, an optical disc having a higher recording capacity has been developed by improving the recording density by using a laser beam having a shorter wavelength than that of the DVD-R.

  For example, a recording medium in which a metal reflective layer, a recording layer, and a cover layer thinner than the base are provided in this order on the base on the premise of recording with light through a high NA lens suitable for high-density recording is disclosed. In addition, a recording / reproducing method is disclosed in which information is recorded / reproduced by irradiating laser light having a wavelength of 450 nm or less from the recording layer side toward the light reflecting layer side. As recording layer forming dyes for information recording media using such short-wave laser light, porphyrin compounds, azo dyes, metal azo dyes, quinophthalone dyes, trimethine cyanine dyes, dicyanovinylphenyl skeleton dyes, and coumarins Compounds have been proposed (for example, JP-A-4-74690, 7-304256, 7-304257, 8-127705, 11-53758, 11-334204). Publication No. 11-334205 Publication No. 11-334206 Publication No. 11-334207 Publication No. 2000-43423 Publication No. 2000-108513 Publication No. 2000-149320 Publication No. 2000-158818 Publication No. 2000-158818 Gazette, 2000-228028 gazette, and 2001-1 Such as the 6074 JP). Those skilled in the art can easily recall that other compounds than those described above can be used as recording layer dyes in principle as long as they can absorb laser light used for recording. As a recording / reproducing laser beam, blue-violet (wavelength 405 nm or 410 nm) is used.

  According to the study of the present inventor, the optical disk using the dye described in the above publication is still not sufficient in terms of sensitivity and recording characteristics necessary for practical use such as reflectance and degree of modulation. There was found. In particular, in the case of a disk configuration in which a metal reflection layer having a relief structure with a narrow groove width and a track pitch on a substrate and a recording layer made of an organic compound are supported in this order, the recording bit to be read is recorded from the adjacent track or recording bit. However, there is a possibility that good signal reproduction cannot be performed due to an increase in noise and jitter. Such an unfavorable tendency becomes more prominent as the wavelength of light used for recording / reproduction becomes shorter.

  The greater the difference in optical properties between the recording and non-recording parts, the easier it is to detect the recording signal of the optical disc, and it is relatively less susceptible to noise, but the optical change is caused by the dyes that make up the recording layer. Depends on the magnitude of changes in optical properties associated with decomposition. Conventionally, when recording / reproducing light having a wavelength of 450 nm or less is used, it has been proposed to use monomethinecyanine or trimethinecyanine having an absorption band in the vicinity of this wavelength. This change should have a longer conjugated system and therefore should be more pronounced for pentamethine cyanine dyes with more π electrons. However, the absorption band of pentamethinecyanine was unsuitable because it was too long. Accordingly, there has been a demand for a dye having an absorption band in a short wavelength region comparable to that of monomethine cyanine or trimethine cyanine even though it has a conjugated system having a π electron number comparable to that of pentamethine cyanine.

  An object of the present invention is to perform recording / reproduction with a laser beam having a wavelength shorter than that used in a CD-R or DVD-R, particularly a wavelength of 450 nm or less, particularly a laser beam having a wavelength of 410 nm or less, which is important for increasing recording density To provide an optical information recording medium in which a recording layer mainly composed of an organic compound is provided on the surface of a metal reflection layer having a relief structure with a narrow groove width and a small track pitch and capable of exhibiting excellent recording characteristics In particular, it is to provide a dye having a conjugated system having a length similar to that of a pentamethine cyanine dye having an absorption maximum wavelength of 410 nm or less.

The problems of the present invention have been solved by the following means.
(1) A cationic compound represented by the following general formula (I).
Formula (I):

In the formula, Q1 represents a group of nonmetallic atoms necessary to complete a 5- or 6-membered heterocycle, and R1 represents an alkyl group, an aralkyl group, an alkenyl group, or an aryl group having 1 to 8 carbon atoms. , G2, G3, and G4 each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an acyl group, an aralkyl group, or an alkenyl group having 1 to 8 carbon atoms. It does not form a ring. Two or more adjacent ones of G2 to G4 are substituents other than hydrogen atoms. A1 and A2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aralkyl group, an alkenyl group, or an aryl group, which may be connected to each other to form a ring. E represents a hydrogen atom or an alkyl group or an aralkyl group having 1 to 8 carbon atoms. When E is a hydrogen atom, there may exist tautomers in which H bonded to Z1 is moved to another position in this structure, and these are also represented by the structure of this general formula. Z1 represents an oxygen atom or a sulfur atom. X ⁿ⁻ represents an n-valent anion for neutralizing the electric charge, and may form an inner salt as a substituent on Q1, R1, G2, G3, and G4. n represents an integer of 1 or more.
(2) The cationic compound according to (1) represented by the following general formula (II).
General formula (II):

In the formula, R 1, G 2, G 3, G 4 and n are as defined in the general formula (I). Z1 represents an oxygen atom or a sulfur atom, T1, T2, T3, and T4 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or an alkenyl group having 1 to 8 carbon atoms, T1 and T2, and T3 and T4 may be connected to each other to form a ring, and the ring may have a substituent. X ⁿ⁻ represents an n-valent anion for neutralizing the electric charge. In this structure, there may exist a tautomer in which H bonded to Z1 is moved to another position, and these are also represented by the structure of this general formula.
(3) The cation compound according to (1) or (2), wherein in general formula (I), G2 and G3 are alkyl groups, and G4 is an alkoxy group.
(4) A method for producing a cationic compound represented by the general formula (I), comprising heating a compound represented by the following general formula (III) and an orthoester in a solvent without the presence of a base. .
General formula (III):

In the formula, Q 1, R 1, X ⁿ⁻ , and n are as defined in general formula (I).
(5) A compound represented by the following general formula (IV) and an orthoester represented by the following general formula (VI) are heated in a solvent without the presence of a base, and the following general formula (V) The manufacturing method of the cation compound represented by these.
Formula (IV):

In the formula, R1, ^Xn- and n have the same meanings as in the general formula (III). Q2 represents an atomic group for completing a benzoxazole, naphthoxazole, benzothiazole, or naphthothiazole ring which may have a substituent.
Formula (V):

In the formula, R 1, Z 1, X ⁿ⁻ , and n are as defined in general formula (I). R3 represents an alkyl group or aralkyl group having 2 to 8 carbon atoms, and R4 represents an alkyl group or aralkyl group having 1 to 8 carbon atoms. R5 represents an alkyl group or an aralkyl group having 1 to 7 carbon atoms. Q2 has the same meaning as in general formula (IV). Q3 represents an atomic group for completing an optionally substituted benzene ring or naphthalene ring.
General formula (VI):
R3-C (OR4) ₃
In the formula, R3 and R4 have the same meanings as in the general formula (V).
(6) The method for producing a cationic compound according to (4) or (5), wherein the solvent is an aprotic solvent.

  The compound of the present invention exhibits an absorption maximum at a short wavelength of 400 nm despite having a π-electron number conjugated system comparable to pentamethinecyanine, and can efficiently absorb light emitted from a blue-violet semiconductor laser. .

  The compound represented by formula (I) will be described in detail.

In the general formula (I), Q1 represents a nonmetallic atom group necessary for completing a 5-membered or 6-membered heterocycle, and R1 represents an alkyl group, an aralkyl group, or an alkenyl group having 1 to 8 carbon atoms. Represents an aryl group, where “having 1 to 8 carbon atoms” is used not only for alkyl groups but also for modifying aralkyl groups, alkenyl groups, and aryl groups, ie, having 1 to 1 carbon atoms. An alkyl group having 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an aryl group having 6 to 8 carbon atoms. The same applies to the following cases. G2, G3, and G4 each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an acyl group, an aralkyl group, or an alkenyl group having 1 to 8 carbon atoms. Will not form. Two or more adjacent ones of G2 to G4 are substituents other than hydrogen atoms. G2 and G3 are preferably an alkyl group having 1 to 6 carbon atoms, an aralkyl group having 6 to 8 carbon atoms, or an aryl group having 6 to 8 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms. It is a group. G4 is preferably an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 6 to 8 carbon atoms, or an aryl group having 6 to 8 carbon atoms, more preferably An alkoxy group having 1 to 6 carbon atoms; A1 and A2 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an alkenyl group, or an aryl group having 1 to 8 carbon atoms, which may be connected to each other to form a ring. E represents a hydrogen atom or an alkyl group or an aralkyl group having 1 to 8 carbon atoms. When E is a hydrogen atom, there may exist tautomers in which H bonded to Z1 moves to another position in this structure, and these are also represented by the structure of this general formula. X ⁿ⁻ represents an n-valent anion for neutralizing the electric charge, and may form an inner salt as a substituent on Q1, R1, G2, G3, and G4. Preferred as the heterocyclic ring completed in Q1 is a benzoxazole ring, a naphthoxazole ring, a benzothiazole ring, or a naphthothiazole ring, and particularly preferably a benzoxazole ring.
R1, G2 to G4 may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, an alkoxy group, a hydroxyl group, a carboxy group, and a sulfo group.
Particularly preferred as A1 and A2 are a hydrogen atom, a methyl group, an ethyl group, or a phenyl group. A ring formed by connecting A1 and A2 to each other is preferably a cyclopentene ring, a cyclohexene ring, a benzene ring, or a naphthalene ring, and particularly preferably a benzene ring. Each ring may further have a substituent, and preferred substituents include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group, and 1 to 6 carbon atoms. An acyl group, a fluorine atom, or a chlorine atom.
Z1 represents an oxygen atom or a sulfur atom, preferably an oxygen atom.
n represents an integer greater than or equal to 1, Preferably it is an integer of 1-4, More preferably, it is an integer of 1-3, More preferably, it is 1 or 2.
In addition, the twist of the methine chain of dicarbocyanine considered to be an intermediate of the synthesis reaction as compared with the case where two or more adjacent ones of G2 to G4 are substituents other than a hydrogen atom as described above. Is increased, the compound represented by the general formula (I) of the present invention can be easily cyclized, and the synthesis yield is increased. Furthermore, since this tendency becomes remarkable, in general formula (I), it is preferable that G2, G3, and G4 are all substituents other than hydrogen atoms. In particular, it is preferable that G2 and G3 are alkyl groups and G4 is an alkoxy group.

  Among the compounds represented by the general formula (I), preferred are the compounds represented by the general formula (II).

In the general formula (II), R1, G2, G3, G4 and n are the same as defined in the general formula (I), and Z1 represents an oxygen atom or a sulfur atom, preferably an oxygen atom. T1, T2, T3, and T4 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aralkyl group, an aryl group, or an alkenyl group, and T1 and T2, and T3 and T4 are connected to each other. To form a ring. X ⁿ⁻ represents an n-valent anion for neutralizing the charge. In this structure, there may be a tautomer in which H bonded to Z1 is moved to another position, and these are also represented by the structure of this general formula.

Particularly preferred as the group represented by R1 is an unsubstituted alkyl group having 1 to 4 carbon atoms or an alkyl group substituted with a fluorine atom or an alkoxy group. Particularly preferred as G2 is a methyl group, ethyl group, propyl group, or benzyl group, and particularly preferred as G3 is a methyl group, ethyl group, or phenyl group. Particularly preferred as G4 is a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a 2-methylpropoxy group, or a benzyloxy group. Particularly preferred as A1, A2, T1, T2, T3, and T4 are a hydrogen atom, a methyl group, an ethyl group, a vinyl group, or a phenyl group. A ring formed by connecting A1 and A2, T1 and T2, and T3 and T4 to each other is preferably a cyclopentene ring, a cyclohexene ring, a benzene ring, or a naphthalene ring, and particularly preferably a benzene ring. Each ring may further have a substituent, and preferred substituents include an alkyl group having 1 to 6 carbon atoms, an alkoxy group, an aryl group, an acyl group, a fluorine atom, or a chlorine atom. Preferred as the anion represented by X are methanesulfonate ion, trifluoromethanesulfonate ion, benzenesulfonate ion, paratoluenesulfonate ion, parachlorobenzenesulfonate ion, naphthalene-1,5-disulfonate ion, 1 -Sulfonate ion such as hydroxynaphthalene-3,6-disulfonate ion, 2,7-dihydroxynaphthalene-3,6-disulfonate ion, chloride ion, bromide ion, iodide ion, tetrafluoroborate ion, tetra Phenylborate ion, hexafluorophosphate ion, perchlorate ion and the like are mentioned, and trifluoromethanesulfonate ion, p-toluenesulfonate ion, naphthalene-1,5-disulfonate ion, 1-hydroxy are particularly preferable. Futaren 3,6-disulfonic acid ion, a 2,7-dihydroxy-3,6-disulfonic acid ion, a tetrafluoroborate ion or a hexafluorophosphate ion.
Of the compounds represented by the general formula (I), more preferable is the compound represented by the general formula (V). In general formula (V), R 1, Z 1, X ⁿ⁻ , and n have the same meaning as in general formula (I), and preferred ones are also the same. R3 represents an alkyl group or aralkyl group having 2 to 8 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, R4 represents an alkyl group or aralkyl group having 1 to 8 carbon atoms, Preferred is an alkyl group having 1 to 6 carbon atoms. R5 represents an alkyl group having 1 to 7 carbon atoms or an aralkyl group, preferably an alkyl group having 1 to 6 carbon atoms. Q2 represents an atomic group for completing a benzoxazole, naphthoxazole, benzothiazole, or naphthothiazole ring, which may have a substituent, preferably benzoxazole or A benzothiazole ring, particularly preferably a benzoxazole ring. Q3 represents an atomic group for completing a benzene ring or a naphthalene ring which may have a substituent, and is preferably a benzene ring which may have a substituent.

  Specific examples of the compound represented by the general formula (I) of the present invention are shown below, but the scope of the present invention is not limited to these.

A method for producing the cationic compound represented by the general formula (I) of the present invention (preferably the cationic compound represented by the general formulas (II) and (V)) will be described.
The cationic compound represented by the general formula (I) of the present invention comprises a compound represented by the general formula (III) and an orthoester (preferably an orthoester represented by the following general formula (VI)) ( It is preferably obtained by heating in an aprotic solvent in the absence of a base. The anion X ⁿ⁻ may be the same as X ⁿ⁻ contained in the compound represented by the general formula (III), but is exchanged with another anion after the synthesis of the compound represented by the general formula (I). You may do it.

In the general formula (III), Q1, R1, X ⁿ⁻ and n have the same definitions as in the general formula (I).

General formula (VI):
R3-C (OR4) ₃
In the formula, R3 and R4 have the same meaning as in the general formula (V).

The solvent used in this synthesis reaction and the amount thereof are such that the compound represented by the general formula (III) (preferably the general formula (IV)), the general formula (VI), or the compound generated during the reaction is precipitated during the reaction. It is preferable to select not to do so. As the solvent, an aprotic solvent is preferable. Examples of preferred aprotic solvents include acetonitrile, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, sulfolane and the like. The amount of solvent or solute concentration in the reaction solution should be selected so that it does not precipitate during the reaction, but those skilled in the art can easily select the solute according to the solute by performing a few preliminary experiments. Can do.
The reaction temperature is preferably refluxed in the vicinity of the boiling point of the solvent used, but is preferably 30 to 300 ° C, more preferably 70 to 200 ° C, and the reaction time is preferably 20 minutes to 10 hours, more preferably 30 minutes to 5 minutes. It's time.

The following pathways can be considered as the mechanism of the chemical reaction constituting this synthesis method. That is, as shown in the following reaction formula, the cyclic enamine (A) generated by the elimination of a proton from CH _{3 of the} compound represented by the general formula (IV) represents the alkoxy group of the orthoester represented by the general formula (VI). Alcohol is eliminated from the chemical species (B) generated by nucleophilic substitution to produce an alkoxyvinyl compound (C). (C) Two molecules bind with the elimination of one molecule of alcohol in the presence of excess orthoester to give dicarbocyanine (D), but are substituted at three adjacent positions on the methine chain. Since there is a group and the steric repulsion is remarkable, it is not an all-trans configuration but a structure in which the methine chain is arranged in a spiral shape, which is considered to be a rapid cyclization. The following reaction mechanism has been described in relation to the compound represented by the general formula (V) as a product, but the same mechanism can be applied to the compound represented by the general formula (I). In Example 2 below, in addition to the compound (S-3) represented by the general formula (I), a compound S-3C corresponding to the alkoxyvinyl body (C) could be isolated. As shown in Example 3 below, even when heated to reflux in acetonitrile, there was no change, but when triethyl orthopropionate was added and heated to reflux, compound S-3 was obtained. This also supports the above reaction mechanism. Therefore, the compound represented by the general formula (VI) is preferably used in an excess amount (mole number) relative to the compound represented by the general formula (IV). Z1-H may be further alkylated with an ortho ester represented by the general formula (VI) to become Z1-E.
Reaction mechanism

  Next, a method for synthesizing the compound represented by the general formula (I) of the present invention will be described with specific examples.

To 8 g (0.05 mol) of 5-chloro-2-methylbenzoxazole manufactured by Wako Pure Chemical Industries, 20 g (0.1 mol) of ethyl paratoluenesulfonate was added and stirred at 160 ° C. for 1.5 hours. Acetone 50 mL was added and cooled to room temperature with stirring. The resulting crystals were collected by filtration, washed with acetone, dried under vacuum, and parachlorotoluenesulfonic acid 5-chloro-3-ethyl-2-methylbenzoxazolium, which is the benzoxazole quaternary salt 1, 7. 7 g was obtained.
Synthesis of compound S-2

56.40 g (320 mmol) of triethyl orthopropionate was added to a solution of 29.43 g (80 mmol) of the benzoxazole quaternary salt 1 in 80 ml of acetonitrile, and the mixture was heated to reflux for 1 hour under a nitrogen stream. After allowing to cool, the solvent was distilled off under reduced pressure, and 10 ml of ethyl acetate and 50 ml of hexane were added to the resulting mixture, and the operation of removing the supernatant was repeated three times. To this was added 10 ml of ethyl acetate, and the resulting crystals were separated by filtration and dried to obtain 13.95 g (20.3 mmol, 50.8%) of the cationic compound S-2 of the present invention as yellow crystals. Melting point: 193-196 ° C (decomposition)
The structure was determined by X-ray crystal structure analysis. The following spectral data is also consistent with this structure.
¹ H NMR (400 MHz, DMSO-d ₆ ) δ 1.03 (t, J = 7 Hz, 3H), 1.15 (t, J = 7 Hz, 3H), 1.25 (t, J = 7 Hz, 3H), 1.45 (t, J = 7 Hz, 3H), 2.09-2.21 (m, 1H), 2.16 (s, 3H), 2.29 (s, 3H), 2.54-2.63 (m, 1H), 3.41-3.50 (m, 1H ), 3.74-3.83 (m, 1H), 4.20-4.36 (m, 3H), 4.67-4.76 (m, 1H), 6.21 (d, J = 10 Hz, 1H), 6.62-6.64 (m, 2H), 6.89 (s, 1H), 7.11 (d, J = 8 Hz, 2H), 7.47 (d, J = 8 Hz, 2H), 7.81 (dd, J = 9, 2 Hz, 1H), 7.89 (d, J = 9 Hz, 1H), 8.53 (d, J = 2 Hz, 1H), 9.89 (s, 1H).
¹³ C NMR (100 MHz, DMSO-d ₆ ) δ 9.3, 11.3, 12.1, 13.2, 13.4, 19.5, 23.0, 42.9, 44.6, 62.8, 99.7, 100.1, 112.9, 114.6, 115.9, 116.7, 121.2, 124.3, 124.4 , 125.6, 126.8, 128.3, 128.7, 131.6, 133.9, 136.5, 143.8, 144.2, 146.0, 147.9, 150.0, 160.8, 164.2.
MALDI-TOFMS (pos) m / z 513 ([S-2 - OTs -] +).
UV-visible absorption spectrum (methanol solution) λ _max (ε _max ) 399 (2420) nm.
It can be seen that the compound S-2 of the present invention exhibits an absorption maximum at a short wavelength of 400 nm and can efficiently absorb the light emitted from the blue-violet semiconductor laser.
The

20 g (0.1 mol) of ethyl paratoluenesulfonate was added to 10.5 g (0.05 mol) of 2-methyl-5-phenylbenzoxazole manufactured by Wako Pure Chemical Industries, and stirred at 160 ° C. for 2 hours. Acetone 100 mL was added and cooled to room temperature with stirring. The resulting crystals were collected by filtration, washed with acetone, air-dried, and 8.9 g of para-toluenesulfonic acid 3-ethyl-2-methyl-5-phenylbenzoxazolium, which was the benzoxazole quaternary salt 2, was obtained. Obtained.
Synthesis of compound S-3

To a solution of 2 g (5 mmol) of the benzoxazole quaternary salt 2 in 10 ml of acetonitrile was added 3.5 g (20 mmol) of triethyl orthopropionate, and the mixture was heated to reflux for 1 hour 50 minutes. After allowing to cool, the solvent was distilled off under reduced pressure, ethyl acetate-hexane 1: 1 100 ml was added to the resulting mixture, and the resulting compound S-3C crystals 680 mg (1.38 mmol, 27.6%) were filtered off. The residue obtained by concentrating the filtrate was treated with column chromatography (silica gel 200 g / ethyl acetate-ethanol 95: 5) to collect the yellow part. The solvent was distilled off, the residue was dissolved in a small amount of ethyl acetate, a trace amount of unwanted substances were removed by filtration, and the solvent was distilled off to obtain 0.6 g (0.78 mmol, 31.2%) of a yellow solid as compound S-3. Got. This was dissolved in isopropyl alcohol, hexane was added, and the precipitated crystals were collected by filtration and dried to obtain 160 mg of a purified product of compound S-3. Melting point: 220.5-221.5 ° C
The following spectral data is consistent with this structure.
¹ H NMR (400 MHz, DMSO-d ₆ ) δ 1.05 (t, J = 7.4 Hz, 3H), 1.20 (t, J = 7.0 Hz, 3H), 1.29 (t, J = 7.3 Hz, 3H), 1.47 (t, J = 6.9 Hz, 3H), 2.01-2.11 (m, 1H), 2.16 (s, 3H), 2.28 (s, 3H), 2.49-2.51 (m, 1H), 3.56-3.63 (m, 1H ), 3.85-3.90 (m, 1H), 4.23-4.42 (m, 3H), 4.83-4.88 (m, 1H), 6.27 (d, J = 8 Hz, 1H), 6.82 (dd, J = 8, 2 Hz, 1H), 6.88 (s, 1H), 6.90 (d, J = 2 Hz, 1H), 7.11 (d, J = 8 Hz, 2H), 7.22-7.33 (m, 8H), 7.47 (d, J = 8 Hz, 2H), 7.46-7.58 (m, 1H), 7.76 (t, J = 7.8 Hz, 2H), 8.42 (d, J = 1.3 Hz, 2H), 9.80 (s, 1H).
MALDI-TOFMS (pos) m / z 597 ([S-3 - OTs -] +).
UV-visible absorption spectrum (methanol solution) λ _max (ε _max ) 394 (2470) nm.
It can be seen that the compound S-3 of the present invention exhibits an absorption maximum at a short wavelength of 400 nm and can efficiently absorb the light emitted from the blue-violet semiconductor laser.

  0.2 g of the compound S-3C obtained in Example 2 above was dissolved in 5 ml of acetonitrile and heated to reflux for 1 hour. The reaction solution was analyzed by thin layer chromatography (TLC), but no change was observed. When 0.2 g of triethyl orthopropionate was added and the mixture was further heated under reflux for 1 hour and 40 minutes, a yellow product was observed on TLC. The solvent was distilled off, 10 ml of hexane-ethyl acetate (1: 1) was added, the resulting solid (100 mg) was filtered off, the filtrate was concentrated, and a small amount of ethyl acetate and hexane were added and left. The resulting yellow crystals were collected by filtration, washed with ethyl acetate-hexane (1: 1) and dried to give 29 mg of yellow crystals. NMR and mass spectrum were consistent with compound S-3 obtained in Example 2.

  Synthesis of Compound S-14

7 mL of acetonitrile was added to 2 g (6.9 mmol) of 3-ethyl-2-methylbenzoxazolium iodide manufactured by Wako Pure Chemical Industries, and dissolved by heating. When 6 g of triethyl orthopropionate was added, crystals were precipitated, but the solution was completely dissolved when the heating was continued and refluxing was started. Red crystals gradually precipitated. After 1 hour at reflux, the reaction mixture was cooled with water, and the resulting 9-ethyloxacarbocyanine iodide red crystals (534 mg, yield 31.8%) were filtered off. The filtrate was concentrated, and the residue was washed with ethyl acetate-hexane 1: 2 (100 mg of the oxacarbocyanine was precipitated from this washing solution, and the total yield of the oxacarbocyanine was 634 mg, and the total yield was 37.7%). Then, silica gel column chromatography (eluting with 170 g of silica gel, eluting with ethyl acetate-ethanol 95: 5), the yellow fraction was collected, and after evaporating the solvent, the residue was washed with ethyl acetate. 66.3 mg (yield 3.4%) was obtained. Mp: 180.2-182.2oC.
The following spectral data is consistent with this structure.
¹ H NMR (300 MHz, DMSO-d ₆ ) δ1.02 (t, J = 7.4 Hz, 3H), 1.15 (t, J = 6.9 Hz, 3H), 1.26 (t, J = 7.3 Hz, 3H), 1.45 (t, J = 6.9 Hz, 3H), 1.91-2.07 (m, 1H), 2.14 (s, 3H), 2.53-2.61 (m, 1H), 3.45-3.50 (m, 1H), 3.71-3.83 ( m, 1H), 4.18-4.41 (m, 3H), 4.67-4.80 (m, 1H), 6.07 (dd, J = 1.7, 9 Hz, 1H), 6.43-6.54 (m, 2H), 6.62 (dd, J = 2, 6 Hz, 1H), 6.85 (s, 1H), 7.67-7.81 (m, 3H), 8.20 (d, J = 8 Hz, 1H), 9.52 (s, 1H).
MALDI-TOFMS (pos) m / z 445 ([S-14-I] ⁺ ).
UV-visible absorption spectrum (methanol solution) λ _max (ε _max ) 394 (2470) nm.

Claims (6)

A cationic compound represented by the following general formula (I).
Formula (I):

In the formula, Q1 represents a group of nonmetallic atoms necessary to complete a 5- or 6-membered heterocycle, and R1 represents an alkyl group, an aralkyl group, an alkenyl group, or an aryl group having 1 to 8 carbon atoms. , G2, G3, and G4 each independently represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an acyl group, an aralkyl group, or an alkenyl group having 1 to 8 carbon atoms. It does not form a ring. Two or more adjacent ones of G2 to G4 are substituents other than hydrogen atoms. A1 and A2 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aralkyl group, an alkenyl group, or an aryl group, and may be connected to each other to form a ring. E represents a hydrogen atom or an alkyl group or an aralkyl group having 1 to 8 carbon atoms. When E is a hydrogen atom, there may exist tautomers in which H bonded to Z1 is moved to another position in this structure, and these are also represented by the structure of this general formula. Z1 represents an oxygen atom or a sulfur atom. X ⁿ⁻ represents an n-valent anion for neutralizing the electric charge, and may form an inner salt as a substituent on Q1, R1, G2, G3, and G4. n represents an integer of 1 or more. The cationic compound of Claim 1 represented by the following general formula (II).
General formula (II):

In the formula, R 1, G 2, G 3, G 4 and n are as defined in the general formula (I). Z1 represents an oxygen atom or a sulfur atom, T1, T2, T3, and T4 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group, or an alkenyl group having 1 to 8 carbon atoms, T1 and T2, and T3 and T4 may be connected to each other to form a ring, and the ring may have a substituent. X ⁿ⁻ represents an n-valent anion for neutralizing the electric charge. In this structure, there may exist a tautomer in which H bonded to Z1 is moved to another position, and these are also represented by the structure of this general formula.   The cationic compound according to claim 1 or 2, wherein, in the general formula (I), G2 and G3 are alkyl groups, and G4 is an alkoxy group. A method for producing a cationic compound represented by the above general formula (I), comprising heating a compound represented by the following general formula (III) and an orthoester in a solvent without the presence of a base.
General formula (III):

In the formula, Q 1, R 1, X ⁿ⁻ and n have the same meaning as in general formula (I). A compound represented by the following general formula (IV) and an ortho ester represented by the following general formula (VI) are heated in a solvent without the presence of a base, and represented by the following general formula (V) A method for producing a cationic compound.
Formula (IV):

In the formula, R1, ^Xn- and n have the same meanings as in the general formula (III). Q2 represents an atomic group for completing a benzoxazole, naphthoxazole, benzothiazole, or naphthothiazole ring which may have a substituent.
Formula (V):

In the formula, R 1, Z 1, X ^n- and n have the same meaning as in general formula (I). R3 represents an alkyl group or aralkyl group having 2 to 8 carbon atoms, and R4 represents an alkyl group or aralkyl group having 1 to 8 carbon atoms. R5 represents an alkyl group or an aralkyl group having 1 to 7 carbon atoms. Q2 has the same meaning as in general formula (IV). Q3 represents an atomic group for completing a benzene ring or naphthalene ring, which may have a substituent.
General formula (VI):
R3-C (OR4) ₃
In the formula, R3 and R4 have the same meanings as in the general formula (V).   The method for producing a cationic compound according to claim 4 or 5, wherein the solvent is an aprotic solvent.