ADDUCTS OF PYRROLE DERIVATIVES TO CARBON ALLOTROPES
20200055820 · 2020-02-20
Assignee
Inventors
Cpc classification
C07D207/323
CHEMISTRY; METALLURGY
C01B2204/04
CHEMISTRY; METALLURGY
B82Y30/00
PERFORMING OPERATIONS; TRANSPORTING
C07D207/325
CHEMISTRY; METALLURGY
B82Y40/00
PERFORMING OPERATIONS; TRANSPORTING
C07D403/06
CHEMISTRY; METALLURGY
International classification
C07D207/323
CHEMISTRY; METALLURGY
C07D403/06
CHEMISTRY; METALLURGY
C07D207/325
CHEMISTRY; METALLURGY
C07F7/18
CHEMISTRY; METALLURGY
Abstract
Adducts are described formed between pyrrole derivatives of formula (I) an carbon allotropes in which the carbon is sp.sup.2 hybridized, such as for example carbon nanotubes, graphene or nanographites, carbon black. The pyrrole derivatives bear substituents on the nitrogen atom suitable for improving the physicochemical characteristics of said allotropes. A process for preparing said adducts is also described. The adducts are formed with a pyrrole of formula (I) wherein X is selected from the group consisting of: The other substituents are as defined in the claims.
##STR00001##
Claims
1. Adduct of a compound of formula (I) ##STR00015## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 are independently selected from the group consisting of: hydrogen, C.sub.1-C.sub.3 alkyl, C.sub.2-C.sub.18 linear or branched alkenyl or alkynyl, aryl, C.sub.1-C.sub.18 linear or branched alkyl-aryl, C.sub.2-C.sub.18 linear or branched alkenyl-aryl, C.sub.2-C.sub.18 linear or branched alkynyl-aryl, heteroaryl, and X is selected from the group consisting of: ##STR00016## wherein R.sub.5 and R.sub.6 are independently selected from the group consisting of: hydrogen, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 linear or branched alkenyl or alkynyl, aryl, C.sub.1-C.sub.22 linear or branched alkyl-aryl, C.sub.2-C.sub.22 linear or branched alkenyl-aryl, C.sub.2-C.sub.22 linear or branched alkynyl-aryl, heteroaryl, or R.sub.5 or R.sub.6 are each or both ##STR00017## wherein m=0, 1, 2 and n=1-30 wherein if only one of R.sub.5 or R.sub.6 is ##STR00018## wherein m=0, 1, 2 and n=1-30 then the other is selected from the group consisting of: hydrogen, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 linear or branched alkenyl or alkynyl; or R.sub.5 and/or R.sub.6 are: ##STR00019## wherein n=0, 1, 2, 3 and R.sub.7, R.sub.7, R.sub.7 are independently selected from the group consisting of: C.sub.1-C.sub.4 alkyl; oxygen-alkyl C.sub.1-C.sub.4 or R.sub.5 and/or R.sub.6 are: ##STR00020## wherein n=0, 1, 2, 3 and R.sub.8 is selected from the group consisting of: C.sub.1-C.sub.4 alkyl; or R.sub.5 and/or R.sub.6 are: ##STR00021## wherein n is an integer from 1 to 10; R.sub.9 is selected from the group consisting of: hydrogen, alkyl, aryl, benzyl, amine, alkylamine, arylamine, benzylamine, aminoaryl; R.sub.10, R.sub.11, R.sub.12, R.sub.13 e R.sub.14 are independently selected from the group consisting of: hydrogen, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.18 linear or branched alkenyl or alkynyl, 1-(4-aminocyclohexyl)methylene; and a carbon allotrope containing carbon atoms hybridized sp.sup.2.
2. Adduct according to claim 1, characterized in that said R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are independently selected from the group consisting of: H, CH.sub.3, CH.sub.2CH.sub.3, phenyl.
3. Adduct according to one or more of the previous claims, characterized in that said carbon allotrope or its derivative is selected from the group consisting of: carbon black, fullerene, single-wall or multiwall carbon nanotubes, graphene, graphite with a number of graphene layers from 2 to 10000.
4. Adduct according to one or more of the preceding claims, characterized in that said carbon allotrope derivative contains functional groups selected from the group consisting of: oxygenated functional groups, preferably hydroxyls, epoxides; functional groups containing carbonyls, preferably aldehydes, ketones, carboxylic acids; functional groups containing nitrogen atoms, preferably amines, amides, nitriles, diazonium salts, imines; functional groups containing sulfur atoms, preferably sulfides, disulfides, mercaptans, sulfones, sulfinic and sulfonic groups.
5. Adduct according to one or more of the preceding claims, characterized in that said derivative of said carbon allotrope is graphite oxide.
6. Adduct according to one or more of the preceding claims, characterized in that said derivative of said carbon allotrope is graphene oxide.
7. Process for the preparation of an adduct according to one or more of the preceding claims, comprising the steps of: vi. providing a solution of a compound of formula (I) in a protic or aprotic polar solvent; vii. providing a suspension of the carbon allotrope in the protic or aprotic polar solvent used for the preparation of the solution referred to in step i.; viii. mixing said solution and said suspension; ix. removing said solvent from said mixture obtained in step iii.
8. Process according to claim 7, characterized by comprising an additional step after said step iv, said step being: x. providing thermal and/or mechanical energy and/or photon irradiation energy to the obtained mixture.
9. Process according to claim 8, characterized in that said thermal energy is provided at a temperature from 50 to 180 C. and for a time from 15 to 360 minutes.
10. Process according to claim 8, characterized in that said mechanical energy is provided for a time from 15 to 360 minutes.
11. Process according to claim 8, characterized in that said photon irradiation energy is provided at a wavelength from 200 to 380 nm and for a time from 30 to 180 minutes.
Description
[0140] Features and advantages of the invention will be better understood from the description of preferred embodiments, illustrated for example in the appended drawings; in which:
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EXAMPLES
[0150] All the chemicals used in the syntheses given in the following examples were obtained from Aldrich and were used without further purification.
[0151] The compositions obtained in the examples presented below were analysed as follows: [0152] analysis by infrared spectroscopy (FT-IR using KBr pellet): adduct/KBr weight ratios of 1:500 were used, and about 80 mg of mixture for forming the pellet. The pellet was analysed using a Fourier transform IR spectrophotometer (Varian 640-IR FT-IR spectrometer with ATR option). The samples were irradiated in a range between 2.5 and 20 m (or between 4000 and 500 cm.sup.1) [0153] UV spectroscopy: the suspensions of adduct (3 mL) were placed, using a Pasteur pipette, in quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument is zeroed with the pure solvent and a UV spectrum is recorded from 200 to 340 nm. A blank of the solvent used was recorded. The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm. [0154] stability in the solvent: after treatment, the powder was placed in a laboratory vial, the appropriate solvent was added (concentration of 1 mg/mL) and it was sonicated for 10 minutes. At the end of sonication (at time t=0) it was analysed by UV spectroscopy. This analysis was then repeated after 1 day and 1 week.
Example 1Synthesis of 1-hexyl-2,5-dimethyl-1H-pyrrole (Hexyl Pyrrole, HP)
[0155] ##STR00010##
[0156] Empirical formula: C12H21N
[0157] Molar mass: 179.30
[0158] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 3.75 g (0.151 mol) of hexylamine and 4.25 g (0.151 mol) of 2,5-hexanedione. The mixture is stirred for 5 hours at 150 C.
[0159] The product is isolated as a light yellow oil, with a yield of 95% and is analysed by gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR).
Example 2Synthesis of 1-hexyl-2,5-dimethyl-1H-pyrrole with Reactants Supported on Graphite as the Carbon Allotrope
[0160] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0161] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 3.75 g (0.151 mol) of hexylamine, 4.25 g (0.151 mol) of 2,5-hexanedione and 10 g of graphite. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy, which revealed the same peaks as shown in
Example 3Synthesis of 1-hexyl-2,5-dimethyl-1H-pyrrole with Reactants Supported on Carbon Black as the Carbon Allotrope
[0162] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0163] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 3.75 g (0.151 mol) of hexylamine, 4.25 g (0.151 mol) of 2,5-hexanedione and 10 g of carbon black. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy, which revealed the same peaks as shown in
Example 4Adduct of 1-hexyl-2,5-dimethyl-1H-pyrrole with Carbon Black
[0164] The hexylpyrrole used is that synthesized in example 1.
[0165] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0166] A 250-mL single-neck flask is charged with 10 g of carbon black and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2.33 g of hexylpyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of carbon black with adsorbed hexylpyrrole.
[0167] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0168] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed repeatedly with distilled water. The filtrate was colourless. The wash water is analysed by UV spectroscopy.
[0169] The samples of adduct that were collected after the indicated thermal treatment times and washing as illustrated, are characterized by FT-IR analysis, performed by preparing a pellet of the sample of adduct in KBr. The IR spectrum in
Example 5Adduct of 1-hexyl-2,5-dimethyl-1H-pyrrole with Graphite
[0170] The hexylpyrrole used is that synthesized in example 1.
[0171] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0172] A 250-mL single-neck flask is charged with 10 g of graphite and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2.33 g of hexylpyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of graphite with adsorbed hexylpyrrole.
[0173] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0174] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed repeatedly with distilled water. The filtrate was colourless. The wash water is analysed by UV spectroscopy.
[0175] The samples of adduct, collected after the indicated thermal treatment times and washing as illustrated, are characterized by FT-IR analysis, performed by preparing a pellet of the sample of adduct in KBr.
Example 6Synthesis of 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (Hexamethylene Bispyrrole, HBP)
[0176] ##STR00011##
[0177] Empirical formula: C.sub.18H.sub.28N.sub.2
[0178] Molar mass: 272.43
[0179] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (8.6 mmol) of hexamethylenediamine and 1.96 g (17.2 mmol) of 2,5-hexanedione. The mixture is stirred for 4 hours at 150 C.
[0180] The product is isolated as dark yellow oil, with a yield of 80% and is analysed by gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR).
Example 7Synthesis of 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane with Reactants Supported on Graphite as the Carbon Allotrope
[0181] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0182] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (8.6 mmol) of hexamethylenediamine, 1.96 g (17.2 mmol) of 2,5-hexanedione and 3 g of graphite. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy.
Example 8Synthesis of 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane with Reactants Supported on Carbon Black as the Carbon Allotrope
[0183] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0184] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (8.6 mmol) of hexamethylenediamine, 1.96 g (17.2 mmol) of 2,5-hexanedione and 3 g of carbon black. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy.
Example 9Adduct of 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane with Nanographite
[0185] The pyrrole compound used (hexamethylene bispyrrole) is that synthesized in example 6.
[0186] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0187] A 250-mL single-neck flask is charged with 10 g of graphite and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of hexamethylene bispyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of graphite with adsorbed hexamethylene bispyrrole.
[0188] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0189] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed repeatedly with distilled water. The filtrate was colourless. The wash water is analysed by UV spectroscopy.
[0190] The samples of adduct that were collected after the indicated thermal treatment times and washing as illustrated, are characterized by FT-IR analysis, performed by preparing a pellet of the sample of adduct in KBr. The IR spectrum in
Example 10Adduct of 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane with Carbon Black
[0191] The pyrrole compound used (hexamethylene bispyrrole) is that synthesized in example 6.
[0192] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0193] A 250-mL single-neck flask is charged with 10 g of carbon black and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of hexamethylene bispyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of carbon black with adsorbed hexamethylene bispyrrole.
[0194] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0195] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed repeatedly with distilled water. The filtrate was colourless. The wash water is analysed by UV spectroscopy.
[0196] The samples of adduct that were collected after the indicated thermal treatment times and washing as illustrated, are characterized by FT-IR analysis, performed by preparing a pellet of the sample of adduct in KBr.
Example 11Synthesis of 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (Pyrrolopropyl Trimethoxysilane (PPTMS)
[0197] ##STR00012##
[0198] Empirical formula: C.sub.12H.sub.23NO.sub.3Si
[0199] Molar mass: 257.14
[0200] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (5.58 mmol) of 3-(trimethoxysilyl)propan-1-amine and 0.640 g (5.58 mmol) of 2,5-hexanedione. The mixture is stirred for 6 hours at 150 C. The product is isolated as a sticky solid of an intense light yellow colour and is analysed by gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). The GC-MS analysis shows the compound 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole as well as unreacted 3-(trimethoxysilyl)propan-1-amine. The yellow solid was then dissolved in dichloromethane. The solution obtained was washed with deionized water. The organic phase was dried over Na.sub.2SO.sub.4 and thoroughly dried at reduced pressure. The solid isolated is the pure compound 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole. The weight of this compound allowed us to calculate a yield equal to 89%.
[0201]
Example 12Synthesis of 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole with Reactants Supported on Graphite as the Carbon Allotrope
[0202] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0203] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (5.58 mmol) of 3-(trimethoxysilyl)propan-1-amine, 0.640 g (5.58 mmol) of 2,5-hexanedione and 3 g of graphite. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy, which revealed the same peaks as shown in
Example 13Synthesis of 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole with Reactants Supported on Carbon Black as the Carbon Allotrope
[0204] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0205] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (5.58 mmol) of 3-(trimethoxysilyl)propan-1-amine, 0.640 g (5.58 mmol) of 2,5-hexanedione and 3 g of carbon black. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Deuterated chloroform (CDCl.sub.3) is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. This liquid is analysed by .sup.1H-NMR spectroscopy, which revealed the same peaks as shown in
Example 14Adduct of 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole with Graphite
[0206] The pyrrole compound used is that synthesized in example 11.
[0207] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0208] A 250-mL single-neck flask is charged with 10 g of graphite and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of hexamethylene bispyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of graphite with adsorbed 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole.
[0209] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0210] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed 3 times with deionized water. The filtrate was colourless. The water from the fourth washing is analysed by UV spectroscopy: no absorption is detected.
[0211] The samples of adduct that were collected after the indicated thermal treatment times and washing as illustrated, are characterized by FT-IR analysis, performed by preparing a pellet of the sample of adduct in KBr. The IR spectrum in
Example 15Adduct of 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole with Carbon Black
[0212] The pyrrole compound used is that synthesized in example 11.
[0213] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0214] A 250-mL single-neck flask is charged with 10 g of carbon black and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of hexamethylene bispyrrole in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of carbon black with adsorbed 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole.
[0215] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0216] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed 3 times with deionized water. The filtrate was colourless. The water from the fourth washing is analysed by UV spectroscopy: no absorption is detected.
Example 16Synthesis of 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine (Dimethylamine Propane Pyrrole DAPP)
[0217] ##STR00013##
[0218] Empirical formula: C.sub.11H.sub.20N.sub.2
[0219] Molar mass: 180.16
[0220] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (9.7 mmol) of N.sup.1,N.sup.1-dimethylpropane-1,3-diamine and 1.10 g (9.7 mmol) of 2,5-hexanedione. The mixture is stirred for 6 hours at 150 C. The product is isolated as an amber-coloured oil and is analysed by nuclear magnetic resonance (NMR), which shows only the expected compound 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine. The weight found and the chemical purity observed by NMR analysis allowed evaluation of a yield equal to 95%.
Example 17Synthesis of 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine with Reactants Supported on Graphite as the Carbon Allotrope
[0221] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0222] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (9.7 mmol) of N.sup.1,N.sup.1-dimethylpropane-1,3-diamine, 1.10 g (9.7 mmol) of 2,5-hexanedione and 3 g of graphite. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Ethyl acetate is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. The supernatant is analysed by thin-layer chromatography, performed with ethyl acetate/hexane solvent mixture (1/9). UV analysis shows haloes with the same R.sub.f (0.6) for the substance 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine obtained in example 16 and for the substance extracted with ethyl acetate from the graphite, as just described.
Example 18Synthesis of 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine with Reactants Supported on Carbon Black as the Carbon Allotrope
[0223] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0224] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (9.7 mmol) of N.sup.1,N.sup.1-dimethylpropane-1,3-diamine, 1.10 g (9.7 mmol) of 2,5-hexanedione and 3 g of carbon black. The flask is equipped with a magnetic stirrer and the mixture is subjected to slow rotation, at a temperature of 150 C. for 2 hours. The reaction mixture is then brought to room temperature. A sample of solid is taken and is put in a test tube. Ethyl acetate is added at room temperature. The test tube is agitated manually for 2 minutes, at room temperature. The suspension contained in the test tube is left to decant. The supernatant is analysed by thin-layer chromatography, performed with ethyl acetate/hexane solvent mixture (1/9). UV analysis shows haloes with the same R.sub.f (0.6) for the substance 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine obtained in example 16 and for the substance extracted with ethyl acetate from the graphite, as just described.
Example 19Adduct of 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine (DAPP) with Graphite
[0225] The pyrrole compound used is that synthesized in example 16.
[0226] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0227] A 250-mL single-neck flask is charged with 10 g of graphite and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of DAPP in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of graphite with absorbed DAPP.
[0228] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0229] After this time the powder is cooled to 25 C. The powder was put in a Bchner with septum and was washed 3 times with deionized water. The filtrate was colourless. The water from the fourth washing is analysed by UV spectroscopy: no absorption is detected.
Example 20Synthesis of O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene Glycol (pyrroloPEG, PPEG)
[0230] ##STR00014##
[0231] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (1.6 mmol) of O-(2-aminopropyl)-O-(2-methoxyethyl)polypropylene glycol (Mn=600) and 0.190 g (1.6 mmol) of 2,5-hexanedione. The mixture is stirred for 6 hours at 150 C. The product is isolated as a very viscous amber-coloured liquid and is analysed by nuclear magnetic resonance (NMR), which shows only the expected compound O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene glycol. The weight found and the chemical purity observed by NMR analysis allowed evaluation of a yield equal to 97%.
Example 21Synthesis of O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene Glycol with Reactants Supported on Graphite as the Carbon Allotrope
[0232] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0233] A 100-mL single-neck flask equipped with a magnetic stirrer is charged with 1 g (1.6 mmol) of O-(2-aminopropyl)-O-(2-methoxyethyl)polypropylene glycol, 0.190 g (1.6 mmol) of 2,5-hexanedione and 3 g of graphite.
Example 22Adduct of O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene Glycol with Graphite as the Carbon Allotrope
[0234] The pyrrole compound used is that synthesized in example 19.
[0235] The graphite used is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0236] A 250-mL single-neck flask is charged with 10 g of graphite and 100 mL of acetone. The suspension is sonicated in an ultrasonic bath for 15 minutes. After this time, a solution of 2 g of O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene glycol in 20 mL of acetone is added. The resultant suspension is sonicated for a further 15 minutes. The solvent is removed at reduced pressure. A powder is obtained, consisting of graphite with adsorbed O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene glycol.
[0237] 0.300 g of powder is put in a 30-mL ampoule equipped with a magnetic stirrer. The reaction mixture is heated at a temperature of 180 C. for 2 hours.
[0238] After this time the powder is cooled to 25 C.
Examples 23-26Stability Tests of Dispersions of the Adducts of Pyrrole Compounds with Graphite in Ethyl Acetate
[0239] The graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0240] The purpose of this test is to verify the capacity of the adduct, consisting of the carbon allotrope, graphite and the pyrrole compound, to form suspensions that are stable over time. The stability in solvents was evaluated in an organic molecule such as ethyl acetate.
[0241] Procedure:
[0242] 10 mg of powdered adduct was put in a 10-mL flask and ethyl acetate (10 mL) was added. The mixture was sonicated in a 2-litre ultrasonic bath, with a power of 260 W, for 20 minutes.
[0243] The suspensions of adduct (3 mL) at a concentration of 1 mg/mL were transferred, using a Pasteur pipette, to quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument was zeroed beforehand with pure solvent, recording a UV spectrum (200-340 nm). The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm.
[0244] To evaluate the stability over time of the suspensions obtained, measurement of UV-Vis absorption was then repeated a week later.
[0245] The results of the stability tests are given in Table 1.
TABLE-US-00001 TABLE 1 Stability tests of dispersions in ethyl acetate of the adducts of pyrrole compounds with graphite.sup.a Example 23 24 25 26 Adduct from Example No. 5 9 14 22 Pyrrole compound HP.sup.b HBP.sup.c PPTMS.sup.d PPEG.sup.e Absorbance at 300 nm t = 0 2.03 4.09 4.09 4.09 t = 1 week 1.10 4.09 4.09 4.09 .sup.aThe graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g. .sup.bHP = 1-hexyl-2,5-dimethyl-1H-pyrrole (hexyl pyrrole) .sup.cHBP = 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (hexamethylene bispyrrole) .sup.dPPTMS = 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (pyrrolopropyl trimethoxysilane) .sup.ePPEG = O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene glycol (pyrroloPEG)
Examples 27-29Stability Tests of Dispersions in Ethyl Acetate of the Adducts of Pyrrole Compounds with Carbon Black
[0246] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0247] The purpose of this test is to verify the capacity of the adduct, consisting of the carbon allotrope, carbon black, and the pyrrole compound, to form suspensions that are stable over time. The stability in solvents was evaluated in an organic molecule such as ethyl acetate.
[0248] Procedure:
[0249] 10 mg of the powdered adduct was put in a 10-mL flask and ethyl acetate (10 mL) was added. The mixture was sonicated in a 2-litre ultrasonic bath, with a power of 260 W, for 20 minutes.
[0250] The suspensions of the adduct (3 mL) at a concentration of 1 mg/mL were transferred, using a Pasteur pipette, to quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument was zeroed beforehand with pure solvent, recording a UV spectrum (200-340 nm). The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm.
[0251] To evaluate the stability over time of the suspensions obtained, measurement of UV-Vis absorption was then repeated a week later.
[0252] The results of the stability tests are given in Table 2.
TABLE-US-00002 TABLE 2 Stability tests of dispersions in ethyl acetate of the adducts of pyrrole compounds with carbon black.sup.a Example 27 28 29 Adduct from Example No. 4 10 15 Pyrrole compound HP.sup.b HBP.sup.c PPTMS.sup.d Absorbance at 300 nm t = 0 2.90 4.09 3.23 t = 1 week 1.21 4.09 2 .sup.aThe carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g. .sup.bHP = 1-hexyl-2,5-dimethyl-1H-pyrrole (hexyl pyrrole) .sup.cHBP = 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (hexamethylene bispyrrole) .sup.dPPTMS = 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (pyrrolopropyl trimethoxysilane)
Examples 30-34Stability Tests of Dispersions in n-Hexane of the Adducts of Pyrrole Compounds with Graphite
[0253] The graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0254] The purpose of this test is to verify the capacity of the adduct, consisting of the carbon allotrope, graphite, and the pyrrole compound, to form suspensions that are stable over time. The stability in solvents was evaluated in an apolar medium, n-hexane.
[0255] Procedure:
[0256] 10 mg of the powdered adduct was put in a 10-mL flask, and n-hexane (10 mL) was added. The mixture was sonicated in a 2-litre ultrasonic bath, with a power of 260 W, for 20 minutes.
[0257] The suspensions of the adduct (3 mL) at a concentration of 1 mg/mL were transferred, using a Pasteur pipette, to quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument was zeroed beforehand with pure solvent, recording a UV spectrum (200-340 nm). The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm.
[0258] To evaluate the stability over time of the suspensions obtained, measurement of UV-Vis absorption was then repeated a week later.
[0259] The results of the stability tests are given in Table 3.
TABLE-US-00003 TABLE 3 Stability tests of dispersions in n-hexane of the adducts of pyrrole compounds with graphite.sup.a Example 30 31 32 33 34 Adduct from Example No. 5 9 14 19 22 Pyrrole compound HP.sup.b HBP.sup.c PPTMS.sup.d DAPP.sup.e PPEG.sup.e Absorbance at 300 nm t = 0 4.10 4.09 3.20 2 4.03 t = 1 day 4.10 4.08 3.01 1.9 4.03 .sup.aThe graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g. .sup.bHP = 1-hexyl-2,5-dimethyl-1H-pyrrole (hexyl pyrrole) .sup.cHBP = 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (hexamethylene bispyrrole) .sup.dPPTMS = 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (pyrrolopropyl trimethoxysilane) .sup.eDAPP = 3-(2,5-dimethyl-1H-pyrrol-1-yl)-N,N-dimethylpropan-1-amine (dimethylamine propane pyrrole) .sup.ePPEG = O-(2-(2,5-dimethylpyrrol-1-yl)propyl)-O-(2-methoxyethyl)polypropylene glycol (pyrroloPEG)
Examples 35-37Stability Tests of Dispersions in n-Hexane of the Adducts of Pyrrole Compounds with Carbon Black
[0260] The carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g.
[0261] The purpose of this test is to verify the capacity of the adduct, consisting of the carbon allotrope, carbon black, and the pyrrole compound, to form suspensions that are stable over time. The stability in solvents was evaluated in an apolar medium, n-hexane.
[0262] Procedure:
[0263] 10 mg of the powdered adduct was put in a 10-mL flask, and n-hexane (10 mL) was added. The mixture was sonicated in a 2-litre ultrasonic bath, with a power of 260 W, for 20 minutes.
[0264] The suspensions of adduct (3 mL) at a concentration of 1 mg/mL were transferred, using a Pasteur pipette, to quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument was zeroed beforehand with pure solvent, recording a UV spectrum (200-340 nm). The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm.
[0265] To evaluate the stability over time of the suspensions obtained, measurement of UV-Vis absorption was then repeated a week later.
[0266] The results of the stability tests are given in Table 4.
TABLE-US-00004 TABLE 4 Stability tests of dispersions in n-hexane of the adducts of pyrrole compounds with carbon black.sup.a Example 35 36 37 Adduct from Example No. 4 10 15 Pyrrole compound HP.sup.b HBP.sup.c PPTMS.sup.d Absorbance at 300 nm t = 0 4.08 4.0 4.02 t = 1 day 4.09 4.0 4.01 .sup.aThe carbon black used is Carbon Black N326 (CB) (Cabot), having the following characteristics: 30 nm average diameter of the spherical particles, surface area equal to 77 m.sup.2/g (determined by nitrogen absorption), absorption of DBP equal to 85 mL/100 g. .sup.bHP = 1-hexyl-2,5-dimethyl-1H-pyrrole (hexyl pyrrole) .sup.cHBP = 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (hexamethylene bispyrrole) .sup.dPPTMS = 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (pyrrolopropyl trimethoxysilane)
Examples 38-40Stability Tests of Dispersions in Toluene of the Adducts of Pyrrole Compounds with Graphite
[0267] The graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g.
[0268] The purpose of this test is to verify the capacity of the adduct, consisting of the carbon allotrope, graphite, and the pyrrole compound, to form suspensions that are stable over time. The stability in solvents was evaluated in an organic solvent such as toluene.
[0269] Procedure:
[0270] 10 mg of the powdered adduct was put in a 10-mL flask and toluene (10 mL) was added. The mixture was sonicated in a 2-litre ultrasonic bath, with a power of 260 W, for 20 minutes.
[0271] The suspensions of adduct (3 mL) at a concentration of 1 mg/mL were transferred, using a Pasteur pipette, to quartz cuvettes with a 1 cm optical path (volume 1 or 3 mL) and were analysed using a UV-Vis spectrophotometer. The instrument was zeroed beforehand with pure solvent, recording a UV spectrum (200-340 nm). The UV-visible spectrum gave the intensity of absorption as a function of the wavelength of the radiation between 200 and 750 nm.
[0272] To evaluate the stability over time of the suspensions obtained, measurement of UV-Vis absorption was then repeated a week later.
[0273] The results of the stability tests are given in Table 5.
TABLE-US-00005 TABLE 5 Stability tests of dispersions in toluene of the adducts of pyrrole compounds with graphite.sup.a Example 38 39 40 Adduct from Example No. 5 9 14 Pyrrole compound HP.sup.b HBP.sup.c PPTMS.sup.d Absorbance at 300 nm t = 0 4.09 4.09 3.32 t = 1 week 4.09 4.09 3.00 .sup.aThe graphite is Synthetic Graphite 8427, acquired from Asbury Graphite Mills Inc., with a minimum carbon content of 99.8 wt % and a surface area of 330 m.sup.2/g. .sup.bHP = 1-hexyl-2,5-dimethyl-1H-pyrrole (hexyl pyrrole) .sup.cHBP = 1,6-bis(2,5-dimethyl-1H-pyrrol-1-yl)hexane (hexamethylene bispyrrole) .sup.dPPTMS = 2,5-dimethyl-1-(3-(trimethoxysilyl)propyl)-1H-pyrrole (pyrrolopropyl trimethoxysilane)