JPS6154057B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thiopyrylium dye and a method for producing the same. It has been known that thiopyrylium and pyrylium dyes are used for various purposes. For example, it is used as an electron-accepting compound in direct positive photographic silver halide emulsions as disclosed in Japanese Patent Publication No. 46-40900, as well as U.S. Patent No. 3141700 by Davis et al.
Spectral sensitizers for photoconductors as described in US Pat. No. 3,250,615 to Allan et al. and US Pat. No. 3,938,994 to Reynolds et al.
It is particularly useful as a spectral sensitizer for organic photoconductors. Photoconductors sensitized with thiopyrylium and pyrylium dyes are used in a variety of applications, such as those disclosed in the above-mentioned patent specifications, but they are particularly important for xerography and electrofax electrophotography. be. However, such conventionally known thiopyrylium dyes have a drawback of having multiple absorption bands in the visible region. In particular, almost all dyes also exhibit absorption in the blue region. That is, this sensitizing dye has spectral sensitization in multiple wavelength ranges. Therefore, when this thiopyrylium dye is used as a sensitizer for photoconductive particles to carry out color copying, for example, when obtaining color images with trichromatic mixed particles by photoelectrophoretic electrophotography, it poses a serious problem. Collide. What is photoelectrophoresis electrophotography? U.S. Patent No. 3384448
As detailed in the specification, a suspension of photoconductive photosensitive particles in an insulating liquid is placed between two electrodes, at least one of which is transparent to light;
When a voltage difference is applied and exposed through a transparent electrode,
This is an electrophotographic method based on the fact that photoconductive photosensitive particles subjected to imagewise exposure move selectively to one electrode to provide a visible image. When this electrophotography is used for color copying, cyan-colored particles that are sensitive to red light are used as photosensitive particles.
Magenta particles that are sensitive to green light and yellow particles that are sensitive to blue light are used, and when this mixed suspension of three-color particles is exposed to white light through a multicolor original image, for example, a color slide, in the above-mentioned apparatus, one image can be obtained. A subtractive color positive or color negative image can be obtained on the transparent electrode with one exposure. As disclosed in U.S. Patent No. 3,384,448, Japanese Patent Publication No. 43-21781, Japanese Patent Application Laid-open No. 52-143827, and elsewhere, the main absorption band of these particles mainly coincides with the main photosensitivity response. In addition to the three-color photoconductive pigments of cyan, magenta, and yellow, as described in U.S. Pat. No. 3,384,448, the photoconductor contains a spectral sensitizer to make it sensitive to visible light. Photosensitive particles can also be used. When a color image is obtained using three-color mixed particles by such photoelectrophoretic electrophotography, if a known thiopyrylium dye is used as a spectral sensitizer for the photosensitive particles, spectral sensitization occurs in multiple wavelength ranges as described above. Therefore, only images with poor color separation could be obtained. That is, the known thiopyrylium dyes were unsuitable for color copying using photoelectrophoretic electrophotography. In order to solve the above-mentioned drawbacks, the inventor of the present invention has made repeated studies and found that it does not have the above-mentioned drawbacks and is more effective for photoconductors than conventional thiopyrylium dyes.
We have discovered a new thiopyrylium dye with high sensitizing ability and a method for producing the same, and have completed the present invention. An object of the present invention is to provide a thiopyrylium dye that provides high sensitizing ability to photoconductive substances and a method for producing the dye. A further object of the present invention is to provide a thiopyrylium dye and a method for producing the same for obtaining images with excellent color separation. The thiopyrylium dye of the present invention is represented by the following chemical structural formula (2,6-di-t-butyl-4-[3-(2,6-di-t-butyl-4H-thiopyran-4-ylidene). ) propen-1-yl]
It is a thiopyrylium salt. The anion represented by Z may be a known single atomic ion or an atomic group ion consisting of a plurality of atoms having a negative charge, preferably an anion of a strong acid represented by HZ with a pKa of 5 or less, preferably a pKa of 2 or less. be. Specific examples of anions include halogen anions, single atomic ions,
Examples include fluoride ion, chloride ion, bromide ion, and iodide ion. Examples of atomic group ions include organic anions such as trifluoroacetate ion, trichloroacetate ion, p-toluenesulfonate ion, and perchlorate ion, periodate ion, tetrachloroaluminate ion, and trichlorophenate () ion. , tetrafluoroborate ion,
Inorganic anions include hexafluorophosphate ion, sulfate ion, hydrogen sulfate ion, and nitrate ion. Among these, in the case of a divalent anion, 1/2 of the anion is formally interpreted as representing a monovalent anion. Among these anions, chloride ion, bromide ion, perchlorate ion, tetrafluoroborate ion, p-toluenesulfonate ion, and trifluoroacetate ion are preferred. The thiopyrylium dye of the present invention can be obtained by reacting 2,6-di-t-butyl-4-methylthiopyrylium salt [compound ()] having the following general formula () with diphenylformamidine or its hydrochloride. Therefore, it can be easily synthesized (manufacturing method) The amount of diphenylformamidine or its hydrochloride used is 0.2 to 5 per mole of compound ().
mol, preferably 0.3 to 1 mol. The reaction between the compound of structural formula () and diphenylformamidine can be carried out by either of the following two methods. (i) When carried out in the presence of an amine. The reaction between compound () and diphenylformamidine can be carried out in the presence of an amine such as an alkyl amine such as piperidine or triethylamine; an aromatic amine such as aniline or dimethylaniline; or an amine such as a nitrogen-containing unsaturated heterocyclic compound such as pyridine or quinoline. It is done. The amount of amine is 0.1 to 10 mol, preferably 0.5 to 10 mol, per mol of thiopyrylium salt.
2 moles are used. However, a large excess of amine may also be used as a solvent. Various other solvents can be used as the solvent, especially alcohols such as ethanol; nitriles such as acetonitrile; ketones such as methyl ethyl ketone; nitro compounds such as nitrobenzene; and halogenated hydrocarbons such as tetrachloroethane. used. Among them, alcohols such as ethanol are preferably used. Reaction time is 10 minutes to 10 hours, preferably 30 minutes to
The reaction temperature for 3 hours is between about 50° C. and the reflux temperature of the solvent or amine, and it is particularly preferable to carry out the reaction near the reflux temperature. The amount of solvent is 1 for 1 g of raw material compound ().
~100 ml is used, preferably 3-10 ml. (ii) When carried out in a carboxylic anhydride, the reaction of compound () with diphenylformamidine can be carried out in a carboxylic anhydride, for example acetic anhydride. The amount of carboxylic anhydride is 1 to 20 ml, preferably 2 to 1 g of compound ().
~10ml. The reaction time is 1 minute to 1 hour, preferably 3 to 10 minutes. The reaction temperature is from around 80°C to reflux temperature (140°C), preferably around 100°C. Further, in the reaction in carboxylic anhydride, it is preferable to add potassium acetate or sodium acetate. The amount of potassium acetate or sodium acetate is 0.5 to 10 mol, preferably around 1 mol, per 1 mol of compound (). As explained above, in the reaction of compound () and diphenylamidine, the above (i) or (ii)
However, when diphenylformamidine hydrochloride is used, in addition to the method (i) or (ii) above, a method of melting diphenylformamidine hydrochloride and compound () can also be adopted. In the case of diphenylformamidine hydrochloride, a melting method is preferred. 2・having the general formula () used in the above reaction
6-di-t-butyl-4-methylthiopyrylium salt is a new substance, which is a compound of 2,6-di-t-butyl-4H-thiopyran-4-one (compound ( )) can be synthesized by reacting with Grignard reagent and then treating with acid. X represents I, Br, or Cl, HZ represents an acid that can be generated by dissociation of an anionic functional group, and Z represents an anionic functional group. In order to obtain the starting compound (), methylmagnesium iodide, methylmagnesium bromide, and methylmagnesium chloride are preferably used as the Grignard reagent to act on the compound (). Further, other organometallic compounds such as methylpotassium, methylsodium, methyllithium, methylcalcium iodide, dimethylberyllium, trimethylaluminum, trimethylboron, etc. can also be used in place of the Grignard reagent. As the solvent, a non-aqueous solvent containing substantially no water can also be used. Examples of solvents include dimethyl ether, methyl ethyl ether, diethyl ether, dimethoxyethane, tetrahydrofuran,
Examples include ether compounds such as 1,4-dioxane, aromatic compounds such as benzene and toluene, and saturated hydrocarbon compounds such as pentane, hexane, cyclohexane, methylcyclohexane, and petroleum ether. Preferred acids used in the above reaction include hydrochloric acid, hydrobromic acid, perchloric acid, tetrafluoroboric acid, trifluoroacetic acid, and p-toluenesulfonic acid. An oxygen-free atmosphere means a rare gas such as helium or argon, or an inert gas such as nitrogen. These gases are used to replace air to form a substantially oxygen-free condition, and the reaction is allowed to proceed under this condition. The pressure of the rare gas or inert gas can be around 1 atm, but the pressure is not limited to this value and can be selected as appropriate. (Described in Japanese Patent Application No. 54-37249 filed on March 28, 1972.) Compound () is a new compound, and GAReynolds
The following four-step process is performed from 2,6-di-t-butyl-4H-pyran-4-one synthesized by the method described in "Journal of Heterocyclic Chemistry", Vol. 11, p. 1075 (1974). I was able to synthesize it with That is, in step (1), heating is performed in the presence of phosphorus pentasulfide,
In the step (2), the reaction is carried out with an alkali sulfide such as sodium sulfide or an alkali hydrosulfide such as potassium bisulfide under an inert gas flow, in the step (3) a methylating agent is reacted, and in the step (4) Hydrolyze the compound obtained in step (3). It is preferable that each step is carried out by a batch method. The thiopyrylium dye of the present invention can also be produced by reacting the 2,6-di-t-butyl-4-methylthiopyrylium salt of the structural formula () with orthoformic acid ester represented by the following general formula ( Manufacturing method) HC(OR) ₃ R is 1 carbon number such as methyl, ethyl, propyl, etc.
Specific examples of orthoformic acid esters having an alkyl group of up to 5 include orthoformic acid methyl ester, orthoformic acid ethyl ester, and orthoformic acid n-propyl ester. Solvents used in the reaction of compound () and orthoformic acid ester include carboxylic acids such as acetic anhydride and acetic acid; amines such as pyridine and piperidine;
Nitriles such as acetonitrile; ketones such as methyl ethyl ketone; nitro compounds such as nitrobenzene; and halogenated hydrocarbons such as tetrachloroethane. Of these, acetic anhydride, acetic acid, pyridine, or a mixture thereof is preferably used. The amount of orthoformate is 0.3 to 10 mol, preferably 0.3 to 10 mol, per 1 mol of compound ().
It is 1.0 mol. The reaction time is 1 minute to 3 hours, preferably 5 minutes to 1 hour, and the reaction temperature is from 50°C to the reflux temperature of the solvent, preferably around 100°C. Other compounds and 2,6-di-t-butyl-4
- A method (manufacturing method) of heating and reacting formylmethylene-4H-thiopyran in a halogenated hydrocarbon, such as 1,2,3-trichloropropane, and a method of heating and reacting a compound and methyl dialkoxy acetate in a solvent. (Manufacturing method) etc. However, method (i) is most preferred in terms of yield and ease of handling of raw materials. The thiopyrylium dyes associated with the present invention are effective in conventional electrophotography and photoelectrophoretic electrophotography methods such as xerography and electrofaxing. It is particularly useful in color electrophotography using photoconductive particles. However, it goes without saying that this description does not limit the usage. FIG. 1 shows the spectral sensitivity spectrum when the novel thiopyrylium dye according to the present invention is used as a spectral sensitizer for poly-N-vinylcarbazole.
FIG. 2 shows a spectral sensitivity spectrum when a conventional thiopyrylium dye is used. As is clear from a comparison of Figures 1 and 2, the new thiopyrylium dye has a thiopyran ring with 2-
Because it has a t-butyl group at the 6-position, unlike conventional dyes with an aryl group, there is no sub-absorption near 400 nm, and a photoconductor composition using this new thiopyrylium dye as a spectral sensitizer can produce blue light in the visible range. It is not sensitive to light in the wavelength range, especially 400 to 450 nm. Therefore, color photoelectrophoretic electrophotographic photosensitive particles containing this new thiopyrylium dye as a sensitizer are different from those made using known thiopyrylium dyes, and have improved color separation from blue-sensitive yellow particles. I can do it. For example, if cyan particles containing the compound () as a sensitizing dye in the red region are mixed with yellow and magenta particles to perform color photoelectrophoresis electrophotography of the three-color mixed particles, an image with good color separation without color mixing with yellow particles will be obtained. . Furthermore, when the new thiopyrylium dye () is used as a sensitizer for photoconductors, especially organic photoconductors such as poly-N-vinylcarbazole, triarylamine, triarylmethane, etc. It has been found that this provides a highly sensitive photoconductor. The reason for this is not yet clear, but one of the reasons seems to be that the t-butyl substituent of compound () increases its compatibility with the organic photoconductor. Next, Examples for producing the thiopyrylium dye of the present invention and comparative examples with conventional thiopyrylium dyes will be shown. Example 1 (i) 2,6-di-t-butyl-4-[3-(2,6
-Di-t-butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium perchlorate (compound). Dissolve 34.6 g of 2,6-di-t-butyl-4H-pyran-4-one in 240 ml of anhydrous benzene, add 73 g of phosphorus pentasulfide, and stir for 2 hours.
The mixture was heated under reflux for 30 minutes. After the reaction was completed, the benzene solution was removed by decanting and aqueous ammonia was added to the residue to decompose phosphorus pentasulfide, followed by extraction with ether and drying using anhydrous sodium sulfate. The solvent of the benzene solution was distilled off under reduced pressure.
The residue was extracted with hexane and concentrated to obtain 16.0 g of reddish crystals. The ether extract and the oil that was not extracted with hexane were combined and purified through a silica gel column using benzene to obtain an additional 6.8 g of crystals. Total yield: 22.8 g 2,6-di-t-butyl-4H-pyran-4-thione was obtained as flesh-colored crystals (recrystallized in hexane) with a melting point of 108-108.5° C. and a yield of 61%. 6.64g of this compound
The mixture was dissolved in 330 ml of hexane methylene phosphoric triamide and argon gas was bubbled through for 20 minutes. Heat and stir over an oil solution at 85°C to 90°C, and add 19.8 g of sodium bisulfide (Wako Pure Chemicals NaSH xH ₂ O approximately 70% to 70% to 70% of phosphorus pentoxide) under an argon atmosphere.
(vacuum dried at 80°C for 1 day) was added once for 30 minutes. After stirring at the same temperature for 1 hour and 30 minutes, the reaction solution was poured into water to complete the reaction. The resulting crystals were filtered and dried. Recrystallized from hexane. 2,6-di-t-butyl-4H-thiopyran-4-thione was obtained as red crystals with a yield of 1.78 g and a yield of 25%, with a melting point of 162°C.
Next, 1.55 g of this compound was heated under reflux for 1 hour with 20 ml of acetone and 5 ml of methyl iodide. After distilling off the solvent under reduced pressure, the residue was recrystallized from acetone to obtain 1.55 g of prismatic red crystals. It was 2,6-di-t-butyl-4-(methylthio)thiopyrylium iodide (compound) with a yield of 63% and a melting point of 150°C to 155°C (decomposition). This 2,6-di-t-butyl-4-(methylthio)thiopyrylium iodide was heated and stirred with 10 ml of dimethyl sulfoxide and 1 ml of water on an oil bath at 85 to 90°C for 3 hours. The reaction solution was poured into water and extracted with diethyl ether. After drying the diethyl ether solution over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the residue was passed through an alumina column using a mixed solvent of benzene diethyl ether at a ratio of 1:1 (volume ratio).
740 mg of crystals were obtained. Yield: 97% Recrystallized from cyclohexane. Colorless crystal, melting point 97-98
2,6-di-t-butyl-4H-thiopyran-4-one was obtained. 550 mg of this compound,
The mixture was dissolved in 20 ml of diethyl ether under an argon atmosphere, and 8.6 ml of a diethyl ether solution (2.7 mmol) of methylmagnesium iodide was added dropwise while cooling to about -10°C. After the dropwise addition was completed, stirring was continued for 45 minutes at room temperature (approximately 23°C), and then a saturated aqueous ammonium chloride solution was added. After decanting the ether solution, the ether was distilled off under reduced pressure and the residue was
20 ml of 35% perchloric acid was added and heated on a hot water bath to precipitate crystals. The crystals were filtered, washed with cold water, further washed with diethyl ether and dried. The yield was 470 mg. Colorless crystals of 2,6-di-t with a melting point of 192-193°C after recrystallization from ethanol.
-Butyl-4-methylthiopyrylium perchlorate (compound) was obtained. Elemental analysis as C ₁₄ H ₂₃ ClO ₄ S Calculated values C = 52.08%, H = 7.18%,
S = 9.93%, actual value C = 52.00%, H = 7.28%,
S=9.75% Infrared absorption spectrum (wavelength cm ^-1 ) 1590, 1375, 1085 Nuclear magnetic resonance spectrum (chemical shift, unit
ppm, trimethylsilane standard) (proton) 99.6MHz in heavy acetone 1.67, 2.96, 8.81 singlets, area ratio 18:
3:2 (Carbon-13) 25.5MHz in heavy acetone 184.87, 167.08, 134.67, 42.53, 31.18,
28.75 Ultraviolet and visible absorption spectra (wavelength nm, log∈ in Katsuko, in acetonitrile) 302 (3.97), 262 (3.88), 213 (4.47) (∈ is extinction coefficient) (ii) 2,6-di-t-butyl -4-[3-(2・6
-di-t-butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium perchlorate (compound) Production of 2,6-di-t-butyl-4-methyl-thiopyrylium perchlorate Chlorate (compound) 0.2g
After heating a mixture of 0.15 g of diphenylformamidine and 0.15 g of diphenylformamidine at 165°C for 5 minutes in a test tube, 0.2 g of the compound, 0.2 g of sodium acetate, and 1 ml of acetic anhydride were added, and the mixture was heated on an oil bath at 165°C for 5 minutes. After heating, it was allowed to cool. Diethyl ether was added, the crystals were filtered, washed with water, dried, and recrystallized from ethyl acetate to obtain 0.128 g of crystals. Yield 36%
2,6-di-tert-butyl-4, melting point 226-227°C
-[3-(2,6-di-t-butyl-4H-thiopyran-4-ylidene)propen-1-i]thiopyrylium perchlorate. Elemental analysis value C ₂₉ H ₄₃ S ₂ ClO ₄ Calculated value C = 62.73%, H = 7.81%,
S=11.55%, actual value C=62.61%, H=7.79%,
S = 11.09% Infrared absorption spectrum (wavenumber cm ^-1 ) 1500, 1272, 1175, 730 Nuclear magnetic resonance spectrum (chemical shift, unit
ppm, based on trimethylsilane in heavy acetone
24℃) 1.49 (single line), 6.61 (double line), 7.85
(single line), 8.82 (triple line), area ratios are respectively
The ratio was 36:2:4:1. Ultraviolet, visible absorption spectrum (wavelength nm) (∈)
in acetonitrile 694 (214000), 645 (74900), 380 (2700),
313 (12700), 232 (11100) Example 2 1 g of poly-N-vinylcarbazole and 3 mg of compound () were dissolved in 10 g of 1,2-dichloroethane and placed on a polyester film deposited with aluminum.
It was applied using a No. 16 rod bar. A photoreceptor was prepared by drying at 55°C for one day. This photoconductor was tested at +6kV using a commercially available device.
After the surface is charged to +450V by corona discharge, the surface is irradiated with light using a tungsten lamp at an illuminance of 4.5 lux, and the time (seconds) until the surface potential reaches 225V is determined to determine the exposure amount. Obtained. The result was E1/2 = 31 lux seconds. Comparative Example 1 A photoreceptor was prepared according to the same photoreceptor manufacturing method as in Example 2, except that the compound () shown in Table 1 below was used instead of the compound () in Example 2, and these photoreceptors are described below. The same measurements as in the example were carried out, and the results shown in Table (1) were obtained. Comparative Example 1 using a known thiopyrylium dye () is a control for comparison with Example 2.

[Table] Example 3 2,6-di-t-butyl-4-[3-(2,6-
Production of di-t-butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium perchlorate (compound) 2,6-di-t-butyl-4-methylthiopyrylium perchlorate ( 0.14 g of compound) and 0.10 g of diphenylformamidine were heated together with 0.08 g of piperidine in 5 ml of ethanol at reflux temperature for 1 hour. After cooling, diethyl ether was added, and the crystals were filtered, washed with water, dried, and recrystallized from ethyl acetate. Yield: 0.08g, melting point:
The temperature was 225-226°C. The infrared absorption spectrum and nuclear magnetic resonance spectrum of this compound were the same as the spectrum of the compound obtained in Example 1. Example 4 2,6-di-t-butyl-4-[3-(2,6-
Production of di-t-butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium perchlorate (compound) 160 mg of the compound () obtained in Example 1 was dissolved in 1 ml of acetic anhydride to give 45 mg. of ethyl orthoformate was added. While stirring, the mixture was heated at 85°C for 10 minutes and then allowed to cool. Diethyl ether was added, the crystals were filtered, and recrystallized from ethyl acetate to obtain 53 mg of crystals. The yield was 20% and the melting point was 226°C. The infrared absorption spectrum and nuclear magnetic resonance absorption spectrum of this crystal were the same as those of the crystal obtained in Example 1. An embodiment is shown below. (1) 2.6 represented by the chemical structural formula () below
-di-t-butyl-4-[3-(2,6-di-t
-butyl-4H-thiopyran-4-ylidene)
Propen-1-yl]thiopyrylium salt. (2) 2,6-di- expressed by the chemical structural formula ()
t-Butyl-4-methylthiopyrylium salt 2,6-di-t-butyl- represented by the chemical structural formula () characterized by reacting with diphenylformamidine or its hydrochloride
Process for producing 4-[3-(2,6-di-t-butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium salt (3) 2,6-di- represented by the chemical structural formula ()
t-Butyl-4-methylthiopyrylium salt 2.6, which is represented by the chemical structural formula (), characterized by the reaction of and orthoformic acid ester
-di-t-butyl-4-[3-(2,6-di-t
-butyl-4H-thiopyran-4-ylidene)
Method for producing propen-1-yl]thiopyrylium salt. (4) The thiopyrylium salt according to embodiment (1), wherein Z is an anion of a strong acid with a pKa of 5 or less. (5) Z is a halogen anion such as fluoride, chloride, bromide, iodide; perchlorate, periodate, tetrachloroaluminate, trichloroferate (), tetrafluoroborate, hexafluorophosphate, sulfate, hydrogen sulfate,
Inorganic anions such as nitrate; and trifluoroacetate, trichloroacetate, p
- Embodiment (1) Thiopyrylium salt, which is an organic anion such as toluenesulfonate. (6) Embodiment (2) in which the reaction between 2,6-di-t-butyl-4-methylthiopyrylium salt and diphenylformamidine or its hydrochloride is carried out in an organic solvent in the presence of an amine. Manufacturing of. (7) The production method according to embodiment (2), wherein the reaction of 2,6-di-t-butyl-4-methylthiopyrylium salt and diphenylformamidine or its hydrochloride is carried out in carboxylic anhydride. (8) The production method according to embodiment (7), in which potassium acetate or sodium acetate is added to carboxylic anhydride. (9) When reacting 2,6-di-t-butyl-4-methylthiopyrylium salt with diphenylformamidine hydrochloride, diphenylamidine hydrochloride and 2,6-di-t-butyl-4-methylthiopyrylium salt are reacted. The manufacturing method according to embodiment (2), in which the lithium salt is melted. (10) The production method according to embodiment (2), in which 0.2 to 5 mol of diphenylformamidine is used per 1 mol of 2,6-di-t-butyl-4-methylthiopyrylium salt. (11) The production method according to embodiment (3), which uses at least one solvent selected from carboxylic acids, nitro compounds, and halogenated hydrocarbons.

[Brief explanation of the drawing]

FIG. 1 shows the spectral sensitivity spectrum when the novel thiopyrylium dye according to the present invention is used as a spectral sensitizer for poly-N-vinylcarbazole.
Figure 2 shows the conventional thiopyrylium dye in poly-N-
This is a spectral sensitivity spectrum when vinyl carbazole is used as a spectral sensitizer.

Claims (1)

[Claims] 1 2.6 represented by the following chemical structural formula ()
-di-t-butyl-4-[3-(2,6-di-t-
Butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium salt. 2 2,6-di- represented by chemical structural formula ()
t-Butyl-4-methylthiopyrylium salt Chemical structural formula () characterized by reacting with diphenylformamidine or its hydrochloride
2,6-di-t-butyl-4-[3
-(2,6-di-t-butyl-4H-thiopyran-
Method for producing 4-ylidene)propen-1-yl]thiopyrylium salt. 3 2,6-di- represented by chemical structural formula ()
t-Butyl-4-methylthiopyrylium salt 2.6, which is represented by the chemical structural formula (), and is characterized by reacting with orthoformic acid ester
-di-t-butyl-4-[3-(2,6-di-t-
A method for producing butyl-4H-thiopyran-4-ylidene)propen-1-yl]thiopyrylium salt.