JPWO2005090275A1 - Hexahydroxytriphenylene monohydrate crystals and process for producing the same - Google Patents

Abstract

In the present invention, an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.0 to 10.1, and a thermal decomposition temperature (Td). Provides 2,3,6,7,10,11-hexahydroxytriphenylene monohydrate type A crystals having a temperature of about 139 ° C. This crystal is excellent in thermal stability. These crystals are produced by maintaining an acetone-water mixed solution of 2,3,6,7,10,11-hexahydroxytriphenylene crystals under reduced pressure and distilling off acetone from the solution.

Description

  The present invention relates to a crystal of hexahydroxytriphenylene monohydrate and a method for producing the same.

  2,3,6,7,10,11-Hexahydroxytriphenylene (hereinafter referred to as “HHTP”) is useful as a raw material for producing functional optical materials such as discotic liquid crystals.

  To date, HHTP crystals are disclosed in, for example, JP-A-8-119894, JP-A-9-118642, JP-A-9-301906, JP-A-11-255781, or JP-A-11-255690. Manufactured in the manner described.

  JP-A-8-119894 discloses a method for producing HHTP by dealkylating 2,3,6,7,10,11-hexaalkoxytriphenylene with hydrogen iodide. In this patent publication, HHTP crystals are isolated by filtering out crystals precipitated in the reaction solution after the dealkylation reaction.

  Japanese Patent Application Laid-Open No. 9-118642 discloses a method for producing HHTP by subjecting a transition metal complex of HHTP and / or a quinone body to reduction treatment. In this patent publication, HHTP crystals are produced by washing and drying the precipitates that precipitate in the reaction solution after the reduction treatment.

  Japanese Patent Application Laid-Open No. 9-301906 discloses a method for producing HHTP by hydrolyzing and / or decomposing alcohol with a carboxylic acid ester or a carbonic acid ester of HHTP. In this patent publication, HHTP crystals are produced by washing and drying crystals that precipitate after hydrolysis and / or alcohol decomposition treatment.

  Japanese Patent Application Laid-Open No. 11-255781 discloses a method for producing HHTP by desilylation of 2,3,6,7,10,11-hexakissilyloxytriphenylene. In this patent publication, the HHTP crystal is produced by washing and drying the crystal precipitated from the reaction solution after the desilylation reaction.

  Japanese Patent Application Laid-Open No. 11-255690 discloses a method for producing an HHTP crystal by detaching a guest compound from an inclusion compound composed of HHTP and a guest compound.

  However, all the HHTP crystals produced by the methods described in the above patent publications have a serious disadvantage that they are poor in thermal stability. Therefore, a device incorporating a functional optical material obtained by using the HHTP type crystal as a raw material has poor durability and has a disadvantage that it cannot exhibit desired performance over a long period of time.

  An object of the present invention is to provide an HHTP crystal having excellent thermal stability (2,3,6,7,10,11-hexahydroxytriphenylene monohydrate type A crystal, hereinafter referred to as “HHTP-A type crystal”). And a manufacturing method thereof.

  As a result of intensive studies to solve the above problems, the present inventors have found that HHTP crystals having excellent thermal stability can be produced by crystallizing HHTP under specific conditions. The present invention has been completed based on such findings.

The present invention provides HHTP-A type crystals shown in the following 1 to 9 and a method for producing the crystals.
1. An HHTP-A type crystal in which an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.0 to 10.1.
2. 2. The HHTP-A type crystal according to 1 above, wherein an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.5 to 9.7.
3. 3. The HHTP-A crystal according to 1 or 2 above, which has a thermal decomposition temperature (Td) of about 139 ° C.
4). HHTP-A type crystal having a thermal decomposition temperature (Td) of about 139 ° C.
5. A method for producing an HHTP-A crystal, wherein HHTP crystals are precipitated by distilling off acetone from an acetone-water mixed solution of HHTP crystals under reduced pressure.
6). 6. The production method according to 5 above, wherein the temperature when acetone is distilled off is about 5 to 65 ° C.
7). 6. The production method according to 5 above, wherein the temperature when acetone is distilled off is about 10 to 55 ° C.
8). 6. The production method according to 5 above, wherein the degree of vacuum when distilling off acetone is about 20 kPa or less.
9. 6. The production method according to 5 above, wherein the degree of vacuum when distilling off acetone is about 0.13 to 18 kPa.

HHTP-A type crystal The HHTP-A type crystal of the present invention comprises a monohydrate of HHTP.

  In the HHTP-A type crystal of the present invention, an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.0 to 10.1. Yes. In the HHTP-A type crystal of the present invention, an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.5 to 9.7. Yes. FIG. 2 shows an X-ray diffraction spectrum of the HHTP-A type crystal of the present invention.

  The thermal decomposition temperature (Td) of the HHTP-A type crystal of the present invention is about 139 ° C.

Method for producing HHTP-A type crystal The HHTP-A type crystal of the present invention is prepared by, for example, dissolving HHTP crystal in a mixture of acetone and water, and then holding the solution under reduced pressure to distill acetone from the solution. It is manufactured by doing.

  Known HHTP crystals can be widely used as the raw material HHTP crystals. For example, the method described in the above-mentioned JP-A-8-119894, JP-A-9-118642, JP-A-9-301906, JP-A-11-255781, or JP-A-11-255690. Any of the produced HHTP crystals can be used. The HHTP-A type crystal of the present invention can be produced by treating the HHTP crystal produced by the method described in these patent documents with the method of the present invention.

  In the present invention, the HHTP crystal as a raw material is dissolved in a mixture of acetone and water. For this operation, as long as the HHTP crystals can be dissolved in a mixture of acetone and water, known dissolving means can be widely applied. Since the raw HHTP crystals are soluble in acetone, it is desirable to first dissolve the HHTP crystals in acetone and then add water to this solution.

  For acetone and water, the ratio of acetone to 100 parts by volume of water in the acetone-water mixed solution is about 50 parts by volume or more, preferably about 50 to 120 parts by volume, more preferably about 100 to 120 parts by volume. use. When an aqueous solution containing HHTP crystals is used, it is preferable to adjust the mixing ratio of acetone and water in consideration of the amount of water contained in the reaction solution.

  Acetone is used in an amount of usually about 20 ml or more, preferably about 20 to 60 ml, more preferably about 20 to 25 ml per 1 g of HHTP crystals as a raw material.

  In the present invention, a solution obtained by dissolving HHTP crystals in a mixture of acetone and water is maintained under reduced pressure, and acetone is distilled off from the solution.

  The temperature at which acetone is distilled off is usually about 5 to 65 ° C, preferably about 10 to 55 ° C, and more preferably about 15 to 50 ° C. If the temperature at which acetone is distilled off is higher than the above range, the HHTP crystals are decomposed to produce by-products, the purity of the HHTP crystals is lowered, and it becomes difficult to obtain the desired HHTP crystals. On the other hand, if the temperature when distilling off acetone is lower than the above range, energy for cooling the acetone-water mixed solution is required, and it takes a long time to distill off acetone, which is not economical. .

  The degree of reduced pressure when distilling off acetone is usually about 20 kPa or less, preferably about 0.13 to 18 kPa, more preferably about 1.3 to 14.5 kPa. If the degree of vacuum is smaller than the above range, a high-performance vacuum pump is required, and the load on the cooling condenser for trapping the distilled acetone becomes very high, which is not economically preferable.

  Since the HHTP-A type crystal of the present invention is soluble in acetone and insoluble in water, it precipitates from the acetone-water mixed solution as the acetone is distilled off. The HHTP-A type crystal of the present invention can be produced by isolating this precipitate by a conventional separation means such as filtration and drying it according to a usual drying means.

  The HHTP-A type crystal of the present invention has excellent thermal stability. Therefore, an apparatus incorporating a functional optical material obtained using the HHTP-A type crystal of the present invention as a raw material has excellent durability, can exhibit desired performance over a long period of time, and maintains high reliability. Can do.

  By the production method of the present invention, the HHTP-A type crystal of the present invention can be easily and industrially advantageously produced.

3 is an X-ray diffraction spectrum diagram of the HHTP-B type crystal obtained in Reference Example 1. FIG. 2 is an X-ray diffraction spectrum diagram of the HHTP-A type crystal obtained in Example 1. FIG. 2 is an IR spectrum diagram of the HHTP-A type crystal obtained in Example 1. FIG.

  The present invention will be further clarified with reference examples, examples, comparative examples and test examples.

Reference example 1
16.5 g (0.15 mol) of catechol was dispersed in 50 ml of 70% sulfuric acid aqueous solution, and 34.2 g (0.15 mol) of ammonium persulfate was added. The mixture was stirred at room temperature for 7 hours, and then the precipitate was collected by filtration and washed with water. To this precipitate, 300 ml of acetone and 1.5 g of activated carbon were added and stirred at room temperature for 30 minutes, and then insoluble matters were filtered off. 300 ml of ion-exchanged water was added to the filtrate, and acetone was distilled off under normal pressure (101.3 kPa) and a distillation temperature (56 to 100 ° C.). The obtained precipitate was collected by filtration and dried under reduced pressure to obtain 14.2 g (yield: 83.1%, purity> 99%) of HHTP crystals (hereinafter referred to as “HHTP-B type crystals”). Obtained.

  The X-ray powder diffraction spectrum of the obtained crystal was measured using RINT2000 / PC manufactured by Rigaku Corporation. The X-ray diffraction spectrum obtained with a copper radiation of λ = 1.5418 through a monochromator had a diffraction pattern as shown in FIG.

  The main peaks of this X-ray diffraction pattern are as follows.

2θ d relative intensity (I / I ₀ )
11.360 7.7828 0.35
17.160 5.1631 0.52
18.200 4.8703 0.14
22.560 3.9380 0.25
26.080 3.4139 0.20
27.640 3.2247 1.00
33.860 2.6645 0.11
44.840 2.0197 0.15.

Example 1
14.2 g of the HHTP-B type crystal obtained in Reference Example 1 was dissolved in 300 ml of acetone, 300 ml of ion-exchanged water was further added, and then acetone was distilled off under reduced pressure. At this time, the distillation temperature gradually increased from 23 ° C. to 50 ° C., and the degree of vacuum gradually changed from 17.1 kPa to 12.1 kPa. As acetone is distilled off, a precipitate is precipitated. The precipitate is collected by filtration and dried under reduced pressure to obtain 13.5 g of HHTP-A crystals (yield 95.0%, purity> 99%). )

  The X-ray powder diffraction spectrum of the obtained crystal was measured using RINT2000 / PC manufactured by Rigaku Corporation. An X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator had a diffraction pattern as shown in FIG.

  The main peaks of this X-ray diffraction pattern are as follows.

2θ d relative intensity (I / I ₀ )
9.220 9.5838 1.00
10.160 8.692 0.39
17.200 5.1512 0.48
26.340 3.3808 0.34
27.660 3.2224 0.41.

  The crystals obtained above were subjected to thermal analysis (TG / DTA).

The conditions of thermal analysis (TG / DTA) are as follows.
TG / DTA measuring device: TG / DTA200 manufactured by SEIKO I & E
Measurement temperature range: 20-600 ° C
Temperature rising rate: 10 ° C./min Carrier gas: Nitrogen (200 ml / min)
Weigh HHTP crystals (about 10 mg) on an open sample pan made of aluminum, put an aluminum crimping cover (with a vent hole in the center) on it, place it on the sample pan of the measuring device, and TG / DTA measurement was performed under measurement conditions. The reference was αAl ₂ O ₃ (about 10 mg).

  As a result of thermal analysis (TG / DTA), the thermal decomposition temperature (Td) of the HHTP crystal obtained above was about 139 ° C.

The measurement conditions of the IR spectrum are as follows.
Measuring device: Analysis side (JIR-RFX3002, manufactured by JEOL Datacom), sensor side (Dura Scope, manufactured by SENS IR Technologies)
Measurement format: Diamond ATR method Background: Air.

Example 2
16.5 g (0.15 mol) of catechol was dispersed in 50 ml of 70% sulfuric acid aqueous solution, and 34.2 g (0.15 mol) of ammonium persulfate was added. The mixture was stirred at room temperature for 7 hours, and then the precipitate was collected by filtration and washed with water. To this precipitate, 300 ml of acetone and 1.5 g of activated carbon were added and stirred at room temperature for 30 minutes, and then insoluble matters were filtered off. 300 ml of ion exchange water was added to the filtrate, and acetone was distilled off under reduced pressure. At this time, the distillation temperature gradually increased from 22 ° C. to 50 ° C., and the degree of vacuum gradually changed from 17.6 kPa to 11.9 kPa. As acetone is distilled off, a precipitate is precipitated. This precipitate is collected by filtration and dried under reduced pressure to give 14.2 g of HHTP-A type crystals (yield 83.1%, purity> 99%). )

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 139 ° C.

Example 3
16.5 g (0.15 mol) of catechol was dispersed in 50 ml of 70% sulfuric acid aqueous solution, and 34.2 g (0.15 mol) of ammonium persulfate was added. The mixture was stirred at room temperature for 7 hours, and then the precipitate was collected by filtration and washed with water. 360 ml of acetone and 1.5 g of activated carbon were added to the precipitate, and the mixture was stirred at room temperature for 30 minutes. After adding 300 ml of ion exchange water to the filtrate, acetone was distilled off under reduced pressure. At this time, the distillation temperature gradually increased from 18 ° C. to 50 ° C., and the degree of vacuum gradually changed from 14.1 kPa to 12.1 kPa. As acetone is distilled off, a precipitate is precipitated. The precipitate is collected by filtration and dried under reduced pressure to give 14.3 g of HHTP-A type crystals (yield 83.6%, purity> 99%). )

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 139 ° C.

Example 4
16.5 g (0.15 mol) of catechol was dispersed in 50 ml of 70% sulfuric acid aqueous solution, and 34.2 g (0.15 mol) of ammonium persulfate was added. The mixture was stirred at room temperature for 7 hours, and then the precipitate was collected by filtration and washed with water. To this precipitate, 500 ml of acetone and 1.5 g of activated carbon were added and stirred at room temperature for 30 minutes, and then insoluble matter was filtered off. After adding 1000 ml of ion-exchanged water to the filtrate, acetone was distilled off under reduced pressure. At this time, the distillation temperature gradually increased from 25 ° C. to 65 ° C., and the degree of vacuum gradually changed from 20.0 kPa to 18.0 kPa. As acetone is distilled off, a precipitate is deposited. The precipitate is collected by filtration and dried under reduced pressure to give 14.0 g of HHTP-A crystals (yield 81.9%, purity> 99%). )

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 139 ° C.

Example 5
16.5 g (0.15 mol) of catechol was dispersed in 50 ml of 70% sulfuric acid aqueous solution, and 34.2 g (0.15 mol) of ammonium persulfate was added. The mixture was stirred at room temperature for 7 hours, and then the precipitate was collected by filtration and washed with water. To this precipitate, 850 ml of acetone and 1.5 g of activated carbon were added and stirred at room temperature for 30 minutes, and then insoluble matter was filtered off. After adding 800 ml of ion-exchange water to the filtrate, acetone was distilled off under reduced pressure. At this time, the distillation temperature gradually increased from 5 ° C. to 45 ° C., and the degree of vacuum gradually changed from 0.67 kPa to 0.13 kPa. As acetone is distilled off, a precipitate is precipitated. The precipitate is collected by filtration and dried under reduced pressure to give 14.1 g of HHTP-A type crystals (yield 82.5%, purity> 99%). )

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 139 ° C.

Reference example 2
An HHTP precursor was synthesized by the method described in JP-A-9-40596. That is, 400 g (2.89 mol) of 1,2-dimethoxybenzene and 944 g (5.76 mol) of anhydrous ferric chloride were dissolved in 4 liters of dichloromethane and stirred at room temperature for 20 hours. After completion of the reaction, the reaction mixture was concentrated, the residue was poured into 3 liters of water, and insoluble matter was collected by filtration. This was added to 1 liter of acetonitrile and stirred at room temperature for 5 hours in a slurry state. Next, this was suction filtered, and the crystals separated by filtration were dried under reduced pressure at 40 ° C. for 12 hours to obtain 360 g of 2,3,6,7,10,11-hexamethoxytriphenylene.

Reference example 3
An HHTP precursor was synthesized by the method described in JP-A-7-330650. That is, 460 g (1.70 mol) of ferric chloride hexahydrate was completely dissolved in warm water (270 ml), and 60 g (0.43 mol) of 1,2-dimethoxybenzene was added thereto. Next, 980 ml of concentrated sulfuric acid was gradually added over 2 hours at room temperature with vigorous stirring. After 24 hours from the end of the addition, 4 liters of ice water was gradually added, and after 1 hour, the reaction mixture was suction filtered, and the crystals separated by filtration were dried under reduced pressure at 40 ° C. for 12 hours to obtain 2, 3, 6, 7, 10 , 11-hexamethoxytriphenylene was obtained.

Reference example 4
An HHTP precursor was synthesized by the method described in JP-A No. 2003-201263. That is, 400 g (2.89 mol) of 1,2-dimethoxybenzene, 1644 g (10.14 mol) of anhydrous ferric chloride and 139 g (1.45 mol) of methanesulfonic acid were mixed in 4 liters of chlorobenzene, 364 ml was added and stirred at 10 ° C. or lower for 4 hours. After completion of the reaction, 3 liters of acetonitrile and 2 liters of water were added to remove the aqueous layer. Furthermore, 2 liters of acetonitrile was added, and the precipitated crystals were suction filtered. The crystals separated by filtration were blown and dried at 40 ° C. for 6 hours to obtain 346 g of 2,3,6,7,10,11-hexamethoxytriphenylene.

Comparative Example 1
HHTP crystals were produced according to the method described in JP-A-8-119894. That is, 51.0 g (0.12 mol) of 2,3,6,7,10,11-hexamethoxytriphenylene obtained in Reference Example 2 was dissolved in 250 ml of acetic acid under a nitrogen atmosphere. To this solution was added 50 ml (0.19 mol) of a 57% aqueous hydroiodic acid solution, and the mixture was refluxed for 6 hours with stirring under a nitrogen atmosphere. The reaction solution was cooled to room temperature, neutralized with an aqueous caustic soda solution, the reaction mixture was filtered with suction, and the crystals separated by filtration were dried under reduced pressure at 40 ° C. for 12 hours to obtain 40.6 g of HHTP crystals (yield 95.0%). , Purity> 99%) was obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 2
HHTP crystals were produced according to the method described in JP-A-8-119894. That is, 51.0 g (0.12 mol) of 2,3,6,7,10,11-hexamethoxytriphenylene obtained in Reference Example 3 was dissolved in 250 ml of acetic acid under a nitrogen atmosphere. To this solution was added 50 ml (0.19 mol) of a 57% aqueous hydroiodic acid solution, and the mixture was refluxed for 6 hours with stirring under a nitrogen atmosphere. The reaction solution was cooled to room temperature, neutralized with an aqueous caustic soda solution, the reaction mixture was filtered with suction, and the crystals separated by filtration were dried under reduced pressure at 40 ° C. for 12 hours to obtain 40.4 g of HHTP crystals (yield 94.5%). , Purity> 98%) was obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 3
HHTP crystals were produced according to the method described in JP-A-8-119894. That is, 51.0 g (0.12 mol) of 2,3,6,7,10,11-hexamethoxytriphenylene obtained in Reference Example 4 was dissolved in 250 ml of acetic acid under a nitrogen atmosphere. To this solution was added 50 ml (0.19 mol) of a 57% aqueous hydroiodic acid solution, and the mixture was refluxed for 6 hours with stirring under a nitrogen atmosphere. The reaction solution was cooled to room temperature, neutralized with an aqueous caustic soda solution, the reaction mixture was filtered with suction, and the crystals separated by filtration were dried under reduced pressure at 40 ° C. for 12 hours to obtain 40.0 g of HHTP crystals (yield 93.5%). , Purity> 99%) was obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 4
HHTP crystals were produced according to the method described in JP-A-9-118642. That is, a mixture of 16.5 g (0.15 mol) of catechol and 81.0 g (0.3 mol) of ferric chloride hexahydrate was heated to 50 ° C. and stirred for 7 hours. The obtained reaction mixture was poured into 300 ml of 3N hydrochloric acid aqueous solution, and the precipitate was separated by filtration and washed with water. This precipitate was dissolved in methanol, the insoluble part was filtered off, water was added to the filtrate, and the precipitated precipitate was filtered off and dried under reduced pressure at 40 ° C. for 12 hours to obtain 7.8 g of HHTP crystals. (Yield 45.6%, purity> 98%) was obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 5
HHTP crystals were produced according to the method described in JP-A-9-118642. That is, a mixture of 16.5 g (0.15 mol) of catechol and 81.0 g (0.3 mol) of ferric chloride hexahydrate was heated to 40 ° C. and stirred for 7 hours. The obtained reaction mixture was poured into 300 ml of 3N hydrochloric acid aqueous solution, and the precipitate was separated by filtration and washed with water. The precipitate was washed with a 10% by weight aqueous sodium hydrosulfite solution until the precipitate turned gray, then washed again with water, and the crystals obtained by suction filtration were dried under reduced pressure at 40 ° C. for 12 hours. 12.6 g of HHTP crystals (yield 73.6%, purity> 97%) were obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 6
HHTP crystals were produced according to the method described in JP-A-9-301906. That is, 333 ml of water was added to 500 g (3.08 mol) of anhydrous ferric chloride under ice cooling. To this mixture, 277 g (1.03 mol) of a 41 wt% catechol aqueous solution was added and stirred at 50 ° C. for 1 hour. After completion of the reaction, 2.3 liters of 3N hydrochloric acid aqueous solution was added, and the mixture was allowed to stand overnight. The precipitated crude crystal HHTP was separated by filtration, washed with water, and then air-dried overnight in a nitrogen stream. To 25 g of the dried crude crystal HHTP, 500 ml of acetic anhydride, 25 g of zinc powder and 20 ml of triethylamine were added and stirred at reflux for 1 hour. The reaction mixture was filtered hot at a temperature of 80-100 ° C. and allowed to stand overnight. The produced crystal was separated by filtration, washed with acetic anhydride, acetone and methanol, and dried to obtain 30.8 g of 2,3,6,7,10,11-hexaacetoxytriphenylene (HATP) crystal.

  The HATP crystals obtained above were dissolved in 240 ml of 2.5% by volume acetic anhydride-dimethylformamide (DMF) solution, filtered hot, allowed to stand overnight, filtered, washed with DMF and methanol. By drying, 19.5 g of HATP crystals with high purity were obtained.

  16.5 g (0.028 mol) of the HATP crystals thus obtained was suspended in 150 ml of ethanol, and 82 ml of 10% aqueous sodium hydroxide solution was added thereto, and the reaction solution turned dark blue. After stirring for 2 hours under reflux, the reaction solution was poured into 300 ml of water, and the pH was adjusted to 1.0 using 6N hydrochloric acid. The solid content precipitated in the reaction solution was separated by filtration and dried under reduced pressure at 40 ° C. for 12 hours to obtain 7.8 g of HHTP crystals (yield 80.0%, purity> 99%).

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 7
HHTP crystals were produced according to the method described in JP-A No. 11-255781. That is, 25.4 g (0.22 mol) of N, N-dimethyltrimethylsilylamine was added to a solution of 10.4 g (0.03 mol) of HHTP-B crystals obtained in Comparative Example 2 in tetrahydrofuran (THF) (100 ml). And stirred at room temperature for 30 minutes and then heated to reflux. After 3 hours, the reaction solution was concentrated on a rotary evaporator, and 300 ml of n-hexane and 30 ml of ethyl acetate were added. Activated carbon was added to the solution, stirred for 30 minutes, filtered by suction, and the filtrate was concentrated to obtain 22.1 g of a crystalline solid. This was recrystallized using acetonitrile to obtain 16.0 g of hexakistrimethylsilyloxytriphenylene (HMSTP) crystals.

  16.0 g (0.021 mol) of the HMSTP crystal obtained above was refluxed in 400 ml of acetic acid for about 1 hour, the reaction solution was cooled to room temperature, and the precipitated crystal was separated by filtration and reduced in pressure at 40 ° C. for 12 hours. By drying, 6.8 g of HHTP crystals (yield 94.0%, purity> 99%) was obtained.

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Comparative Example 8
HHTP crystals were produced according to the method described in JP-A-11-255690. That is, a mixture of 15.0 g (0.14 mol) of catechol and 146.8 g (0.54 mol) of ferric chloride hexahydrate was heated to 50 to 60 ° C. and stirred for 7 hours. The obtained reaction mixture was poured into 200 ml of 3N aqueous hydrochloric acid solution, and the precipitate was separated by filtration, washed with water, and washed with saturated sodium bicarbonate. The obtained solid was dried under reduced pressure at 40 ° C. for 12 hours to obtain 17.0 g of a black solid containing HHTP.

  The obtained black solid was dissolved in 100 ml of cyclopentanone by heating and then filtered while hot, and the filtrate was concentrated under reduced pressure to obtain 6.13 g of an inclusion compound composed of crude HHTP and cyclopentanone. . Furthermore, when this was heated and dissolved in 100 ml of cyclopentanone and then cooled to room temperature, 7.13 g of crystals in which 3 molecules of cyclopentanone were included in 1 molecule of HHTP was obtained.

  The inclusion crystal was dried at 95 ° C. under reduced pressure for 12 hours to obtain 4.0 g of HHTP crystal (yield 25.0%, purity> 99%).

  As a result of powder X-ray diffraction measurement of this crystal, it had the same diffraction pattern as that shown in FIG. Further, when the crystal was subjected to thermal analysis (TG / DTA), the thermal decomposition temperature (Td) was about 162 ° C. Therefore, it was confirmed that this crystal was an HHTP-B type crystal.

Test example 1
The HHTP-A type crystals obtained in Examples 1 to 5 and the HHTP-B type crystals obtained in Comparative Examples 1 to 8 were each placed in a light-shielding glass bottle and allowed to stand for 1 month in a 60 ° C. constant temperature bath. Thereafter, these crystals were taken out and subjected to X-ray measurement. As a result, no change was observed in the X-ray diffraction patterns of these crystals.

Test example 2
50 mg each of the HHTP-A type crystals obtained in Examples 1 to 5 and the HHTP-B type crystals obtained in Comparative Examples 1 to 8 were dissolved in methanol to prepare a methanol solution having a total amount of 100 ml. This methanol solution was put into a cell, and UV-visible spectroscopic analysis was performed using methanol as a reference. A cell having an optical path length of 10 mm was used, and a spectrophotometer U-3000 manufactured by Hitachi, Ltd. was used as the ultraviolet-visible spectroscopic analysis instrument. Absorbance at 360 nm and 520 nm was measured.

  The HHTP-A type crystals obtained in Examples 1 to 5 and the HHTP-B type crystals obtained in Comparative Examples 1 to 8 were put in a light-shielding glass bottle and left in a constant temperature bath at 60 ° C. for 1 month, and then The absorbance at 360 nm and 520 nm was also measured for 50 mg of the crystals in the same manner as described above.

  The results are shown in Table 1.

  From Table 1, it can be seen that the HHTP-A type crystals obtained in Examples 1 to 5 are excellent in thermal stability, and the coloring degree before and after being left at 60 ° C. for 1 month is at the same level. Moreover, it can be seen from Table 1 that the HHTP-B type crystals obtained in Comparative Examples 1 to 8 have poor thermal stability and are markedly colored when left at 60 ° C. for 1 month.

Claims (9)

  An X-ray diffraction spectrum obtained with a copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.0 to 10.1, 2, 3, 6, 7, 10, 11 -Hexahydroxytriphenylene monohydrate type A crystal.   The crystal according to claim 1, wherein an X-ray diffraction spectrum obtained with copper radiation of λ = 1.5418 through a monochromator has a peak at a lattice spacing (d) of 9.5 to 9.7.   The crystal according to claim 1 or 2, wherein the thermal decomposition temperature (Td) is about 139 ° C.   2,3,6,7,10,11-hexahydroxytriphenylene monohydrate type A crystal having a thermal decomposition temperature (Td) of about 139 ° C.   Acetone is distilled off under reduced pressure from an acetone-water mixed solution of 2,3,6,7,10,11-hexahydroxytriphenylene crystals to obtain 2,3,6,7,10,11-hexahydroxytriphenylene crystals. Of 2,3,6,7,10,11-hexahydroxytriphenylene monohydrate A-type crystals.   The production method according to claim 5, wherein the temperature at which acetone is distilled off is about 5 to 65 ° C.   The production method according to claim 5, wherein the temperature at which acetone is distilled off is about 10 to 55 ° C.   The production method according to claim 5, wherein the degree of reduced pressure when distilling off acetone is about 20 kPa or less.   The production method according to claim 5, wherein the degree of reduced pressure when distilling off acetone is about 0.13 to 18 kPa.

Images