CN112409250B - Direct aromatization process of cyanopyridine - Google Patents
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- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/60—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D213/78—Carbon atoms having three bonds to hetero atoms, with at the most one bond to halogen, e.g. ester or nitrile radicals
- C07D213/84—Nitriles
Abstract
The invention discloses a direct aromatization process of p-cyanopyridine, which comprises the steps of taking tetrafluoroborate diazobenzene salt and p-cyanopyridine as raw materials under the atmosphere of nitrogen and the irradiation of visible light, providing reaction excitation energy by the irradiation of the visible light, taking the tetrafluoroborate diazobenzene salt as an arylation reagent, taking an organic dye as a photo-oxidation reducing agent, directly performing arylation reaction on the p-cyanopyridine in an acetonitrile solvent, and directly coupling an ortho-position C-H bond of N on the p-cyanopyridine with phenyl to obtain the p-cyanopyridine aromatic derivative, wherein the reaction condition is mild, the selectivity is good, and the yield of the p-cyanopyridine aromatic derivative can reach 65-85%; the direct aromatization process of the cyanopyridine provided by the invention does not use expensive metal reagents or organic metal reagents, and the organic dye has the advantages of low price, lower production cost and high reaction yield, and is suitable for popularization and application.
Description
Technical Field
The invention relates to the technical field of preparation processes of aromatic pyridine derivatives, in particular to a direct aromatization process of cyanopyridine.
Background
In the direct arylation synthesis process of N-heterocyclic aromatic hydrocarbon, the most common method is to halogenate N-heterocyclic compound (Ar) under the catalysis of transition metal N X) coupling reaction with different arylating reagentsThe corresponding arylation product is obtained. The arylating reagent in the reaction comprises some aryl nonmetal compounds and aryl metal compounds; in addition, some arylsulfinate salts can also be used as arylating agents for desulfurization and arylation reactions, and there are reports of direct arylation using stable-quality benzene via C-H activation. These synthetic methods have effectively promoted the diversification of the arylation reaction of N-heterocyclic compounds, but still have some disadvantages, such as: the presence of transition metal intermediates increases the complexity of the reaction, the reaction requires the search for suitable ligands, the reaction involves noble metal reagents and the functional groups of the reaction are not sufficiently compatible, etc.
When the organic reaction adopts visible light as reaction energy, higher chemical reaction yield and atom economy can be obtained under mild conditions, and energy consumption and waste emission can be greatly reduced, which has important practical significance for relieving energy shortage and reducing environmental pollution. Therefore, the invention provides a method for performing arylation coupling reaction on cyanopyridine at room temperature by using cheap and easily-obtained organic dye as a photooxidation reducing agent and common diazonium tetrafluoroborate as an arylation reagent.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide a direct aromatization process for cyanopyridine, wherein visible light irradiation is utilized to provide reaction excitation energy, tetrafluoroborate diazobenzene salt is used as an arylation reagent, an organic dye is used as a photo-oxidation reducing agent, the direct arylation reaction is carried out on the cyanopyridine in an acetonitrile solvent, the ortho-position C-H bond of N on the cyanopyridine is directly coupled with phenyl to obtain the aromatic derivative of the cyanopyridine, the reaction condition is mild, the selectivity is good, and the yield of the aromatic derivative of the cyanopyridine can reach 65-85%; expensive metal reagents or organic metal reagents are not used, and the organic dye has the advantages of low price, low production cost, high reaction yield and suitability for popularization and application.
In order to achieve the purpose, the technical scheme of the invention is to design a direct aromatization process of cyanopyridine, which comprises the following steps: preparing tetrafluoroborate diazobenzene salt; under the atmosphere of nitrogen and the irradiation of visible light, taking tetrafluoroborate diazobenzene salt and p-cyanopyridine as raw materials, taking an organic dye as a photo-oxidation reducing agent, and placing the raw materials, the tetrafluoroborate diazobenzene salt and the p-cyanopyridine into a reaction solvent containing trifluoroacetic acid to be heated, stirred and reacted for a certain time; after the reaction is finished, the mixed solution of the reaction product is subjected to extraction, organic phase concentration to remove organic dye, and organic phase concentrated solution column chromatography separation and purification in sequence to obtain the arylation derivatives of the cyanopyridine;
the tetrafluoroborate diazobenzene salt is selected from one of diazobenzene tetrafluoroborate, p-bromodiazobenzene tetrafluoroborate, p-methylbenzdiazobenzene tetrafluoroborate and p-methoxyl diazobenzene tetrafluoroborate; the organic dye is selected from one of eosin Y (molecular structural formula shown in the specification, see formula I), eosin B (molecular structural formula shown in the specification, see formula II) and rhodamine B (molecular structural formula shown in the specification, see formula III),
the molar charge ratio of the tetrafluoroboric acid diazobenzene salt to the trifluoroacetic acid is 1:10 to 20.
The preferable technical proposal is that the solvent for extraction is dichloromethane and saturated saline; the concentrated solution is separated and purified by column chromatography, and is eluted by a mixed solvent of normal hexane and ethyl acetate with the volume ratio of 7-10: 1.
The preferable technical proposal is that the mol ratio of the tetrafluoroborate diazobenzene salt to the cyanopyridine to the organic dye is 1: 1-8: 0.03-0.10.
Further preferably, the mol ratio of the tetrafluoroborate diazobenzene salt to the cyanopyridine to the organic dye is 1: 1-5: 0.05.
The preferable technical proposal is that the reaction temperature is 20-35 ℃ and the reaction time is 12-30 h.
Further preferably, the reaction temperature is 25 ℃, and the reaction time is 22h.
In a preferred technical scheme, the reaction solvent is acetonitrile.
In a preferred technical scheme, the p-cyanopyridine arylation derivative is an N-ortho C-arylation p-cyanopyridine arylation derivative.
The invention has the advantages and beneficial effects that:
1. the direct aromatization process of the cyanopyridine provided by the invention utilizes visible light irradiation to provide reaction excitation energy, uses tetrafluoroborate diazobenzene salt as an arylation reagent and uses an organic dye as a photo-oxidation reducing agent, directly performs arylation reaction on the cyanopyridine in an acetonitrile solvent, directly couples an ortho-position C-H bond of N on the cyanopyridine and a phenyl group to obtain the aromatic derivative of the cyanopyridine, and has the advantages of mild reaction conditions, good selectivity and yield of the aromatic derivative of the cyanopyridine of 65-85%.
2. The direct aromatization process of the cyanopyridine provided by the invention does not use expensive metal reagents or organic metal reagents, and the organic dye has the advantages of low price, lower production cost and high reaction yield, and is suitable for popularization and application.
Drawings
FIG. 1 is a flow chart of a process for the preparation of a diazonium tetrafluoroborate benzenesalt;
FIG. 2 is a process flow diagram for the direct aromatization of a cyanopyridine.
Detailed Description
The following description of the embodiments of the present invention will be made with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Example 1
The 2-phenyl-4-cyanopyridine is prepared according to the process of the invention, and the steps are as follows:
(I) synthesis of diazobenzene tetrafluoroborate: as shown in FIG. 1, 10mmol of aniline, 4.0mL of distilled water, and 3.4mL of 50% hydrofluoroboric acid were sequentially added to a 25mL single-neck flask, and the reaction was started while maintaining the temperature at 0 ℃ or lower; slowly dripping 1.5mL of 1mol/mL sodium nitrite solution dropwise within 5min, reacting for 40min, and filtering to obtain a solid crude product; completely dissolving the solid crude product and acetone according to a molar ratio of 1; the diazobenzene tetrafluoroborate is placed in a watch glass, dried in vacuum and stored in a reagent bottle for later use.
Synthesis of (di) 2-phenyl-4-cyanopyridine: as shown in FIG. 2, in a 25mL single-neck flask, 192mg of diazobenzene tetrafluoroborate (1 mmol), 49.98mg of eosin Y (0.07 mmol), 312mg of p-cyanopyridine (3 mmol), 745. Mu.L of trifluoroacetic acid (10 mmol), and 4mL of acetonitrile are added under a nitrogen blanket; the reaction is stopped after the reaction is finished after the reaction solution is irradiated for 20 hours by 460nm blue light at the room temperature of 25 ℃; the resulting mixture was diluted with 10mL of dichloromethane, neutralized with 1mL of 5% aqueous sodium bicarbonate solution, the organic phase was extracted 3 times with 15mL each time saturated brine, and then with anhydrous Na 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is separated by column chromatography through a mixed solvent of normal hexane and ethyl acetate (the volume ratio of the normal hexane to the ethyl acetate is 7: 1) to obtain 0.113g of yellow solid, namely the target product 2-phenyl-4-cyanopyridine (the molecular structural formula is shown as formula 1), and the product yield is 68% (calculated by diazobenzene tetrafluoroborate). The melting point of the target product 2-phenyl-4-cyanopyridine is 85-86 ℃, and the nuclear magnetic resonance hydrogen spectrum data and the nuclear magnetic resonance carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.86(dd,J＝5.0,1.0Hz,1H),8.12–7.97(m,2H),7.97–7.85(m,1H),7.54–7.34(m,4H)；
13 C NMR(75MHz,CDCl 3 ),d＝157.8,149.6,136.3,129.2,128.1,126.0,122.2,121.1,120.2,115.7；
example 2
The process for preparing the 2- (4-bromophenyl) -4-cyanopyridine comprises the following steps:
(I) synthesis of p-bromodiazobenzene tetrafluoroborate: the synthesis method was the same as that of diazobenzene tetrafluoroborate in example 1.
Synthesis of (di) 2- (4-bromophenyl) -4-cyanopyridine: in a 25mL single-neck flask, under nitrogen, 270mg of para-bromodiazobenzene tetrafluoroborate (1 mmol), 35mg of eosin Y (0.05 mmol), 520mg of para-cyanopyridine (5 mmol), 745. Mu.L of trifluoroacetic acid (10 mmol) and 4mL of acetonitrile are added; at the room temperature of 25 ℃, after being irradiated for 22 hours by blue light with the wavelength of 465nm, the reaction is stopped; the resulting mixture was diluted with 10mL of dichloromethane, neutralized with 1mL of 5% aqueous sodium bicarbonate solution, the organic phase was extracted 3 times with 15mL each time saturated brine, and then with anhydrous Na 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is separated by column chromatography through a mixed solvent of normal hexane and ethyl acetate (the volume ratio of the normal hexane to the ethyl acetate is 9: 1) to obtain light yellow solid 0.135g, namely the target product 2- (4-bromophenyl) -4-cyanopyridine (the molecular structural formula is shown as formula 2), and the product yield is 74% (calculated by the bromobenzobistetrafluoroborate). The melting point of the target product 2- (4-bromophenyl) -4-cyanopyridine is 96-98 ℃, the infrared spectrum and the nuclear magnetic resonance spectrum are consistent with the reported literature data, and the nuclear magnetic resonance hydrogen spectrum data and the nuclear magnetic resonance carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.78(dd,J＝4.9,0.9Hz,1H),7.96–7.73(m,3H),7.65–7.48(m,2H),7.40(dd,J＝5.0,1.4Hz,1H)；
13 C NMR(75MHz,CDCl 3 ,ppm)δ156.7,151.3,138.0,132.1,128.4,124.6,123.7,122.3,121.7,119.8；
example 3
The process for preparing 2- (4-methylphenyl) -4-cyanopyridine comprises the following steps:
(I) Synthesis of para-methyl diazobenzene tetrafluoroborate: the synthesis method is the same as that of diazobenzene tetrafluoroborate in example 1.
Synthesis of (di) 2- (4-methylphenyl) -4-cyanopyridine: in a 25mL single-neck flask, under a nitrogen blanket, 210mg of para-methyldiphenyldiazonium tetrafluoroborate (1 mmol), 64.26mg of eosin Y (0.09 mmol), 624mg of para-cyanopyridine (6 mmol), 745. Mu.L of trifluoroacetic acid (10 mmol) and 4mL of acetonitrile are added; at the room temperature of 25 ℃, after being irradiated for 25 hours by blue light with the wavelength of 465nm, the reaction is stopped; the resulting mixture was diluted with 10mL of dichloromethane, neutralized with 1mL of 5% aqueous sodium bicarbonate solution, the organic phase was extracted 3 times with 15mL each time saturated brine, and then with anhydrous Na 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is subjected to column chromatography by using a mixed solvent of normal hexane and ethyl acetate (the volume ratio of the normal hexane to the ethyl acetate is 10: 1) to obtain 0.088g of a yellow-green solid, namely a target product 2- (4-methylphenyl) -4-cyanopyridine (the molecular structural formula is shown in formula 3), and the product yield is 82% (calculated by the p-methyl diazobenzene tetrafluoroborate). Wherein the melting point of the target product 2- (4-methylphenyl) -4-cyanopyridine is 83-84 ℃, and the nuclear magnetic resonance hydrogen spectrum data and the nuclear magnetic resonance carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.87(d,J＝5.0Hz,1H),8.05–7.92(m,3H),7.50–7.41(m,2H),7.35(d,J＝7.3Hz,1H),2.43(s,3H)；
13 C NMR(75MHz,CDCl 3 )δ151.9(C),143.3(CH),142.4(C),141.5(C),140.5(C),134.0(C),130.2(CH),129.9(2CH).129.6(CH),129.3(CH),129.1(CH),127.5(2CH),21.5(CH 3 )；
example 4
The process for preparing 2- (4-methoxyphenyl) -4-cyanopyridine comprises the following steps:
(I) synthesis of p-methoxy diazobenzene tetrafluoroborate: the synthesis method was the same as that of diazobenzene tetrafluoroborate in example 1.
Synthesis of (di) 2- (4-methoxyphenyl) -4-cyanopyridine: in a 25mL single-neck flask, under the protection of nitrogen, add248mg of p-methoxyphenyldiazonium tetrafluoroborate (1 mmol), 35mg of eosin Y (0.05 mmol), 520mg of p-cyanopyridine (5 mmol), 745. Mu.L of trifluoroacetic acid (10 mmol) and 4mL of acetonitrile; at the room temperature of 25 ℃, after being irradiated for 16 hours by blue light with the wavelength of 450nm, the reaction is stopped; the resulting mixture was diluted with 10mL of dichloromethane, neutralized with 1mL of 5% aqueous sodium bicarbonate solution, the organic phase was extracted 3 times with 15mL each time saturated brine, and then with anhydrous Na 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is separated by column chromatography through a mixed solvent of normal hexane and ethyl acetate (the volume ratio of the normal hexane to the ethyl acetate is 9: 1) to obtain 0.121g of yellow solid, namely the target product 2- (4-methoxyphenyl) -4-cyanopyridine (the molecular structural formula is shown as formula 4), and the product yield is 80% (calculated by the p-methoxy diazobenzene tetrafluoroborate). Wherein the melting point of the target product 2- (4-methoxyphenyl) -4-cyanopyridine is 112-114 ℃, and the nuclear magnetic resonance hydrogen spectrum data and the nuclear magnetic resonance carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.99(dd,J＝5.5,0.9Hz,1H),8.00(dd,J＝1.5,0.8Hz,1H),7.91–7.80(m,2H),7.62(dd,J＝5.5,1.5Hz,1H),7.15–7.02(m,2H),3.91(s,3H)。
1 C NMR(75MHz,CDCl 3 ,ppm)δ161.4,158.5,150.5,129.9,128.4,122.3,121.2,121.0,114.4,55.4；
example 5
The process for preparing 2- (4-bromophenyl) -4-cyanopyridine comprises the following steps:
(I) synthesis of para-bromodiazobenzene tetrafluoroborate: the synthesis method was the same as that of diazobenzene tetrafluoroborate in example 1.
Synthesis of (di) 2- (4-bromophenyl) -4-cyanopyridine: in a 25mL single-neck flask, under nitrogen, 270mg of para-bromodiazobenzene tetrafluoroborate (1 mmol), 31mg of eosin B (0.05 mmol), 520mg of para-cyanopyridine (5 mmol), 1.49mL of trifluoroacetic acid (20 mmol) and 4mL of acetonitrile are added;at the room temperature of 20 ℃, after being irradiated for 24 hours by blue light with the wavelength of 450nm, the reaction is stopped; the resulting mixture was diluted with 10mL of dichloromethane, neutralized with 1mL of 5% aqueous sodium bicarbonate solution, the organic phase was extracted 3 times with 15mL each time saturated brine, and then with anhydrous Na 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is separated by column chromatography through a mixed solvent of normal hexane and ethyl acetate (the volume ratio of the normal hexane to the ethyl acetate is 8: 1) to obtain 0.128g of solid, namely a target product 2- (4-bromophenyl) -4-cyanopyridine (the molecular structural formula is shown as formula 2), and the product yield is 70.2% (calculated by the bromobenzotetrafluoroborate). The melting point of the target product 2- (4-bromophenyl) -4-cyanopyridine is 96-98 ℃, and the nuclear magnetic resonance hydrogen spectrum data and the nuclear magnetic resonance carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.78(dd,J＝4.9,0.9Hz,1H),7.96–7.73(m,3H),7.65–7.48(m,2H),7.40(dd,J＝5.0,1.4Hz,1H)；
13 C NMR(75MHz,CDCl 3 ,ppm)δ156.7,151.3,138.0,132.1,128.4,124.6,123.7,122.3,121.7,119.8。
example 6
The process for preparing 2- (4-bromophenyl) -4-cyanopyridine comprises the following steps:
(I) synthesis of p-bromodiazobenzene tetrafluoroborate: the synthesis method was the same as that of diazobenzene tetrafluoroborate in example 1.
Synthesis of (di) 2- (4-bromophenyl) -4-cyanopyridine: in a 25mL single-neck flask, under nitrogen protection, 270mg of para-bromodiazobenzene tetrafluoroborate (1 mmol), 24mg of rhodamine B (0.05 mmol), 520mg of para-cyanopyridine (5 mmol), 373. Mu.L of trifluoroacetic acid (5 mmol), and 4mL of acetonitrile are added; at the room temperature of 20 ℃, after being irradiated for 24 hours by blue light with the wavelength of 460nm, the reaction is stopped; the resulting mixture was diluted with 10mL of dichloromethane and neutralized with 1mL of 5% aqueous sodium bicarbonate, the organic phase was extracted 3 times with 15mL of saturated brine each time, and anhydrous Na was added 2 SO 4 Drying, filtering, and removing the solvent by reduced pressure distillation to obtain a crude product; the crude product is treated by a mixed solvent of n-hexane and ethyl acetate (n-hexane)And the volume ratio of ethyl acetate is 10: 1) to obtain 0.124g of solid, namely the target product 2- (4-bromophenyl) -4-cyanopyridine (with the molecular structural formula shown in the formula 2), and the product yield is 68 percent (calculated by the bromobenzo-diazonium tetrafluoroborate). The melting point of the target product 2- (4-bromophenyl) -4-cyanopyridine is 96-98 ℃, and the nuclear magnetic resonance hydrogen spectrum data and the carbon spectrum data are as follows:
1 H NMR(300MHz,CDCl 3 ,ppm)δ8.78(dd,J＝4.9,0.9Hz,1H),7.96–7.73(m,3H),7.65–7.48(m,2H),7.40(dd,J＝5.0,1.4Hz,1H)；
13 C NMR(75MHz,CDCl 3 ,ppm)δ156.7,151.3,138.0,132.1,128.4,124.6,123.7,122.3,121.7,119.8。
the reaction mechanism in example 1 (as shown in formula 5): visible light irradiation is utilized to provide reaction excitation energy, tetrafluoroborate diazobenzene salt is used as an arylation reagent, eosin Y (organic dye) is used as a photo-oxidation reducing agent, a proper amount of trifluoroacetic acid is added into an acetonitrile solvent to facilitate the dissolution of the organic dye, the direct arylation reaction of the cyanopyridine is catalyzed, the ortho-position C-H bond of N on the cyanopyridine is directly coupled with phenyl to obtain the aromatic derivative of the cyanopyridine, the reaction condition is mild, the selectivity is good, and the yield of the aromatic derivative of the cyanopyridine can reach 65-85%.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, it is possible to make various improvements and modifications without departing from the technical principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.
Claims (6)
1. A process for directly aromatizing cyanopyridine is characterized by comprising the following steps: preparing tetrafluoroborate diazobenzene salt; under the atmosphere of nitrogen and irradiation of visible light, taking tetrafluoroborate diazobenzene salt and cyanopyridine as raw materials, taking organic dye as a photo-oxidation reducing agent, and placing the raw materials, the tetrafluoroborate diazobenzene salt and the cyanopyridine into a reaction solvent containing trifluoroacetic acid to be heated, stirred and reacted for a certain time; after the reaction is finished, the mixed solution of the reaction product is subjected to extraction, organic phase concentration to remove the solvent and column chromatography separation and purification in sequence to obtain the cyanopyridine arylation derivative;
the tetrafluoroborate diazobenzene salt is selected from one of diazobenzene tetrafluoroborate, p-bromodiazobenzene tetrafluoroborate, p-methylbenzdiazobenzene tetrafluoroborate and p-methoxyl diazobenzene tetrafluoroborate; the organic dye is selected from one of eosin Y, eosin B and rhodamine B;
the molar charge ratio of the tetrafluoroborate diazobenzene salt to the trifluoroacetic acid is 1:10 to 20;
the molar charge ratio of the tetrafluoroborate diazobenzene salt to the cyanopyridine to the organic dye is 1: 1-8: 0.03-0.10;
the reaction temperature is 20-35 ℃, and the reaction time is 12-30 h.
2. The process for the direct aromatization of a cyanopyridine of claim 1 wherein the extraction solvent is dichloromethane or saturated brine; the concentrated solution is separated and purified by column chromatography, and is eluted by a mixed solvent of normal hexane and ethyl acetate with the volume ratio of 7-10: 1.
3. The process for the direct aromatization of a cyanopyridine of claim 1 wherein the molar charge ratio of the diazobenzene tetrafluoroborate to the cyanopyridine to the organic dye is from 1:1 to 5: 0.05.
4. The process for the direct aromatization of a cyanopyridine of claim 1 wherein the reaction temperature is 25 ℃ and the reaction time is 22 hours.
5. The process for the direct aromatization of a cyanopyridine of claim 1 wherein the reaction solvent is acetonitrile.
6. The process for the direct aromatization of a cyanopyridine according to claim 1 wherein the arylated derivative of a cyanopyridine is an N-o C-arylated para-cyanopyridine arylated derivative.
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