A method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons

Abstract

The present invention relates to a method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons, the method comprising: reacting nitroaromatic hydrocarbons shown in formula I and metal chloride salts in an organic solvent at 25 to 75° C. under the catalysis of a metal salt catalyst and under the irradiation of light with a wavelength of 365 nm to 450 nm, to obtain chlorinated aromatic compounds. Based on the method of the present invention, nitroaromatic hydrocarbons and metal chloride salts are used as main raw materials, and denitration and chlorination of nitro compounds are achieved through photoinduced and metal salt catalysis. The reaction uses less raw materials and reagents, and the reaction conditions are simple, with step economy and atom economy, and the substrate range is wide, which is convenient for further derivatization of the conversion product to prepare complex functional molecules.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis, and particularly relates to a method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons. Background Art

[0002] Aromatic nitro compounds are widely available and inexpensive. They are not only important raw materials for the preparation of aromatic compounds, but also precursors of energetic compounds, and can be converted into other aromatic compounds as new electrophiles. There are relevant literature reports on the construction of CO, CS, CC and CN bonds by transition metal-catalyzed Suzuki cross-coupling reactions of aromatic nitro compounds. In 2017, the Nakao research group achieved the cross-coupling reaction of non-activated nitrobenzene, and the construction of carbon-carbon bonds, carbon-nitrogen bonds and carbon-hydrogen bonds of nitrobenzene catalyzed by palladium was reported by the research group. However, there are few studies on the direct conversion of nitro groups into corresponding C-Cl bonds to prepare chlorinated aromatic compounds.

[0003] At present, there are two traditional conversion methods for aromatic nitro compounds to other aromatic compounds: one is to reduce nitrobenzene to obtain aromatic amines, and then construct carbon-carbon bonds or carbon-heteroatom bonds through diazotization and Sandmeyer reaction; the other is to convert nitro compounds containing electron-withdrawing groups into other aromatic compounds through aromatic nucleophilic substitution (S N The nitro group can be converted into other groups by the reaction of Ar). Among the above traditional conversions, the former has shortcomings in step economy and atom economy, and diazonium salts with explosion hazards need to be handled during the reaction, while the latter substrate is limited to substrates containing electron-withdrawing groups, and the substrate range is still limited. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons, so as to solve the problems of complex steps and narrow substrate application range in the prior art.

[0005] The specific solutions provided by the present invention include the following:

[0006] The present invention provides a method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons, the method comprising: reacting nitroaromatic hydrocarbons shown in formula I and metal chloride salts in an organic solvent at 25 to 75° C. under the catalysis of a metal salt catalyst and under the irradiation of light with a wavelength of 365 nm to 450 nm to obtain chlorinated aromatic compounds shown in formula II, and the specific reaction equation is as follows:

[0007]

[0008] Wherein, Ar is one of a substituted or unsubstituted aromatic group and a heteroaromatic group;

[0009] The organic solvent is acetonitrile;

[0010] The metal salt catalyst is selected from one or more of FeCl3, CuCl2 or AlCl3.

[0011] The technical solution of the present invention has the following beneficial effects:

[0012] Based on the method of the present invention, nitroaromatic hydrocarbons and metal chloride salts are used as main raw materials, and the denitrification and chlorination of nitro compounds are achieved through light initiation and metal salt catalysis. The reaction uses fewer raw materials and reagents, and the reaction conditions are simple. It has step economy and atom economy, and the substrate range is wide, which facilitates the further derivatization of the conversion products to prepare complex functional molecules.

[0013] On the basis of the above scheme, the present invention can also be improved as follows:

[0014] Furthermore, the substituent of the substituted aromatic group or heteroaromatic group is selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl or amide.

[0015] Furthermore, the aromatic group is selected from one of phenyl, styryl or condensed ring aromatic groups, and the heteroaromatic group is selected from one of furyl, pyridyl, benzopyridyl, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl or quinolyl.

[0016] Furthermore, the metal salt catalyst is FeCl3.

[0017] Furthermore, the metal chloride salt is selected from one of NaCl and LiCl.

[0018] Furthermore, the reaction temperature is 55-75°C.

[0019] Furthermore, the molar ratio of the nitroaromatic hydrocarbon, the metal chloride and the metal salt catalyst is 1:(0.8-3):(0.2-0.35).

[0020] Furthermore, an oxidizing agent potassium peroxydisulfate (oxone) is added during the reaction.

[0021] Furthermore, the molar ratio of the nitroaromatic hydrocarbon to the oxidant is 1:(0.35-3).

[0022] Further, the nitroaromatic hydrocarbon is selected from one of the following structures:

[0023]

[0024] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below. The embodiments described below are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0026] The method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons according to the embodiment of the present invention comprises: in an organic solvent, using nitroaromatic hydrocarbons shown in formula I and metal chloride salts as raw materials, reacting at 25 to 75° C. under the irradiation of light with a wavelength of 365 nm to 450 nm in the presence of a metal salt catalyst to obtain chlorinated aromatic compounds shown in formula II. The specific reaction equation is as follows:

[0027]

[0028] Wherein, Ar is one of a substituted or unsubstituted aromatic group and a heteroaromatic group;

[0029] The organic solvent is acetonitrile;

[0030] The metal salt catalyst is selected from one or more of FeCl3, CuCl2 or AlCl3.

[0031] The technical solution of the present invention has the following beneficial effects:

[0032] Based on the method of the present invention, nitroaromatic hydrocarbons and metal chloride salts are used as main raw materials, and the denitrification and chlorination of nitro compounds are achieved through light initiation and metal salt catalysis. The reaction uses fewer raw materials and reagents, and the reaction conditions are simple. It has step economy and atom economy, and the substrate range is wide, which facilitates the further derivatization of the conversion products to prepare complex functional molecules.

[0033] Preferably, the substituent of the substituted aromatic group or heteroaromatic group is selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl or amide.

[0034] Preferably, the substituent in the substituted aromatic group is phenyl. For biphenyl type substrates, a higher product yield can be obtained at room temperature.

[0035] Based on the method for preparing chlorinated aromatic compounds by photoinduced denitrification and chlorination of nitroaromatic hydrocarbons according to the embodiment of the present invention, the aromatic group is selected from one of phenyl, styryl or condensed ring aromatic groups, and the heteroaromatic group is selected from one of furanyl, pyridine, benzopyridine, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl or quinolyl.

[0036] Preferably, the metal salt catalyst is FeCl3.

[0037] Catalyst and light are used to synergistically excite and activate the denitrification and chlorination of nitrobenzene. FeCl3 can be used as both a chlorine source and a catalyst, and the catalytic activation performance of FeCl3 is higher than that of CuCl2 and AlCl3.

[0038] Preferably, the metal chloride salt is selected from one of NaCl and LiCl.

[0039] Preferably, the reaction temperature is 55-75° C. Based on the reaction of the present invention, the reaction temperature is low and the reaction can be carried out at room temperature. As the temperature increases, the yield increases, and a higher yield can be obtained at 55-75° C.

[0040] Preferably, the molar ratio of the nitroaromatic hydrocarbon, the metal chloride and the metal salt catalyst is 1:(0.8-3):(0.2-0.35).

[0041] Specifically, the method according to the present invention can be carried out in both air and inert atmosphere.

[0042] Preferably, an oxidant potassium peroxydisulfate (oxone) is also added during the reaction. Adding an oxidant during the process of catalyst and light synergistically exciting and activating nitrobenzene denitrification and chlorination can further increase the yield of the target product.

[0043] Preferably, the molar ratio of the nitroaromatic hydrocarbon to the oxidant is 1:(0.35-3).

[0044] Preferably, the nitroaromatic hydrocarbon is selected from one of the following structures:

[0045]

[0046] Accordingly, the chlorinated aromatic compound shown in formula II is selected from one of the following structures:

[0047]

[0048] Example 1

[0049] Preparation of 4-chlorobenzonitrile:

[0050] The specific reaction formula is as follows:

[0051]

[0052] The specific preparation process is as follows:

[0053] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equivalent), potassium peroxydisulfate (207.8 mg, 0.60 mmol, 3.0 equivalent), 4-nitrobenzonitrile (29.6 mg, 0.20 mol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was then purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 4-chlorobenzonitrile (yield 16.7 mg, 61%).

[0054] On a silica gel thin layer plate using n-hexane-ethyl acetate as a developing solvent (the volume ratio of n-hexane to ethyl acetate is 50:1), the Rf of the product was measured to be 0.3.

[0055] The structural characterization data of the product are as follows:

[0056] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.61 (d, J = 8.0Hz, 2H), 7.47 (d, J = 8.4Hz, 2H) ppm.

[0057] 13 C NMR (100MHz, CDCl3, 25℃, δ): 139.6, 133.4, 129.7, 118.0, 110.8ppm

[0058] HRMS-EI(m / z)calc'd for C7H4ClCN + [M] + ,137.0027;found,137.0026.

[0059] Example 2

[0060] Preparation of 2,3-dichlorophenol

[0061]

[0062] The specific preparation process is as follows:

[0063] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equiv), NaCl (35.0 mg, 0.60 mmol, 3.0 equiv), 3-chloro-2-nitrophenol (34.6 mg, 0.20 mmol, 1.0 equiv) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a mixture of n-hexane / ethyl acetate to obtain a colorless oily product 2,3-dichlorophenol (yield 20.5 mg, yield 63%).

[0064] On a silica gel thin layer plate, using n-hexane-ethyl acetate as a developing solvent (the volume ratio of n-hexane to ethyl acetate was 5:1), the Rf of the product was measured to be 0.5.

[0065] The structural characterization data of the product are as follows:

[0066] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.12 (dd, J1=J2=8.0Hz, 1H), 7.12 (d, J=7.2Hz, 1H), 6.94 (d, J=8.0Hz, 1H), 5.69 (s, 1H)ppm.

[0067] 13 C NMR (100MHz, CDCl3, 25℃, δ): 152.7, 132.6, 128.1, 122.2, 119.0, 114.4ppm

[0068] HRMS-EI(m / z)calc'd for C6H4Cl2O[M] + ,161.9634;found,161.9632.

[0069] Example 3

[0070] Preparation of 4-chloro-1,1'-biphenyl

[0071] The specific reaction formula is as follows:

[0072]

[0073] The specific preparation process is as follows:

[0074] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 4-nitro-1,1'-biphenyl (39.8 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with n-hexane as the eluent to obtain a colorless solid product 4-chloro-1,1'-biphenyl (yield 33.6 mg, yield 89%).

[0075] The product was measured on a silica gel thin layer plate using n-hexane as the developing solvent, and Rf = 0.5.

[0076] The structural characterization data of the product are as follows:

[0077] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.54–7.48(m,4H),7.44–7.32(m,5H)ppm.

[0078] 13 C NMR (100MHz, CDCl3, 25℃, δ): 140.0, 139.7, 133.4, 129.0, 128.9, 128.5, 127.7, 127.1ppm.

[0079] HRMS-EI(m / z)calc'd for C 12 H8Cl + [M] + ,188.0387;found,188.0381.

[0080] Example 4

[0081] Preparation of 4'-chloro-2-trifluoromethoxy-1,1'-biphenyl

[0082] The specific reaction formula is as follows:

[0083]

[0084] The specific preparation process is as follows:

[0085] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 4'-nitro-2-trifluoromethoxy-1,1'-biphenyl (56.6 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, with the eluent being a hexane / ethyl acetate mixture, to obtain a colorless oily product 4'-chloro-2-trifluoromethoxy-1,1'-biphenyl (yield 46.8 mg, yield 86%).

[0086] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), and the Rf of the product was measured to be 0.5.

[0087] The structural characterization data of the product are as follows:

[0088] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.46–7.42(m,4H),7.41–7.37(m,4H)ppm.

[0089] 13 C NMR (100MHz, CDCl3, 25℃, δ): 146.1, 135.3, 134.2, 133.9, 131.4, 130.6, 129.0, 128.6, 127.2, 121.5, 120.4 (d, J = 256.2Hz) ppm.

[0090] 19 F NMR (400MHz, CDCl3, 25℃, δ): –57.2ppm

[0091] HRMS-ESI(m / z)calc'd for C 13 H8ClF3O[M+H] + ,273.0289;found,273.0280.

[0092] Example 5

[0093] Preparation of '4-chloro-2,3,4,5,6-pentafluoro-1,1'-biphenyl

[0094] The specific reaction formula is as follows:

[0095]

[0096] The specific preparation process is as follows:

[0097] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equivalent), 2,3,4,5,6-pentafluoro-4'-nitro-1,1'-biphenyl (57.8 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product '4-chloro-2,3,4,5,6-pentafluoro-1,1'-biphenyl (yield 42.3 mg, yield 76%).

[0098] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), and the Rf of the product was measured to be 0.6.

[0099] The structural characterization data of the product are as follows:

[0100] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.48 (d, J = 8.4Hz, 2H), 7.37 (d, J = 8.4Hz, 2H) ppm.

[0101] 13 C NMR (100MHz, CDCl3, 25℃, δ): 144.1 (m, J = 247.0Hz), 140.5 (m, J = 271.0Hz), 137.9 (m, J = 251.0Hz), 135.6, 131.5, 129.1, 124.8, 114.8 (d, J = 16.7Hz) ppm

[0102] 19 F NMR (400MHz, CDCl3, 25℃, δ): –143.15(m,2F), –154.7(t,J=22.4Hz,1F), –161.8(m,2F)ppm

[0103] HRMS-EI(m / z)calc'd for C 12 H4ClF5 + [M] + ,277.9916;found,277.9913.

[0104] Example 6

[0105] Preparation of 2-(4-chlorophenyl)isoindoline-1,3-dione

[0106]

[0107] The specific preparation process is as follows:

[0108] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equiv), NaCl (35.0 mg, 0.60 mmol, 3.0 equiv), 2-(4-nitrobenzene)isoindoline-1,3-dione (53.6 mg, 0.20 mmol, 1.0 equiv) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 2-(4-chlorophenyl)isoindoline-1,3-dione (yield 40.1 mg, yield 78%).

[0109] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 20:1), and the Rf of the product was measured to be 0.3.

[0110] The structural characterization data of the product are as follows:

[0111] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.00–7.97 (m, 2H), 7.85–7.82 (m, 2H), 7.51 (d, J = 8.8Hz, 2H), 7.43 (d, J = 8.8Hz, 2H) ppm.

[0112] 13 C NMR (100MHz, CDCl3, 25℃, δ): 167.0,134.6,133.8,131.6,130.2,129.3,127.7,123.9ppm

[0113] HRMS-ESI(m / z)calc'd for C 14 H8ClNO2[M+Na] + ,280.0136;found,280.0149.

[0114] Example 7

[0115] Preparation of N-(4-chloro-2-fluorophenyl)benzamide

[0116] The specific reaction formula is as follows:

[0117]

[0118] The specific preparation process is as follows:

[0119] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equiv), NaCl (35.0 mg, 0.60 mmol, 3.0 equiv), N-(2-fluoro-4-nitrobenzene)benzamide (52 mg, 0.20 mmol, 1.0 equiv) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation of 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, with the eluent being a hexane / ethyl acetate mixture, to obtain a yellow solid product N-(4-chloro-2-fluorobenzene)benzamide (yield 29.9 mg, yield 60%).

[0120] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 20:1), and the Rf of the product was measured to be 0.35.

[0121] The structural characterization data of the product are as follows:

[0122] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.34 (dd, J1=J2=9.2Hz, 1H), 7.97 (s, 1H), 7.79 (d, J=7.6Hz, 2H), 7.52–7.40 (m, 3H), 7.09–7.06 (m, 2H)ppm.

[0123] 13 C NMR (100MHz, CDCl3, 25℃, δ): 165.6, 152.4 (d, J = 245.1Hz), 134.2, 132.4, 129 .0,127.1,125.3(d,J=10.1Hz),124.9(d,J=3.4Hz),122.5,115.8,115.6ppm.

[0124] 19 F NMR (400MHz, CDCl3, 23℃, δ): –128.5ppm

[0125] HRMS-ESI(m / z)calc'd for C 13H9ClFNO[M+H] + ,250.0429;found,250.0434.

[0126] Example 8

[0127] Preparation of 1-chloronaphthol

[0128] The specific reaction formula is as follows:

[0129]

[0130] The specific preparation process is as follows:

[0131] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equivalent), 1-nitronaphthol (34.6 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless oily product 1-chloronaphthol (yield 24.6 mg, yield 76%).

[0132] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 100:1), and the Rf of the product was measured to be 0.3.

[0133] The structural characterization data of the product are as follows:

[0134] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.27 (d, J = 8.4Hz, 1H), 7.84 (d, J = 8.0Hz, 1H), 7.75 (d, J = 8.4Hz, 1H), 7.61-7.51 (m, 3H), 7.37 (dd, J1 = J2 = 8.4Hz, 1H) ppm.

[0135] 13 C NMR (100MHz, CDCl3, 25℃, δ): 134.6, 132.0, 130.8.128.3, 127.2, 127.1, 126.7, 126.2, 125.8, 124.4ppm.

[0136] HRMS-EI(m / z)calc'd for C 10 H7Cl + [M] +,162.0231;found,162.0226.

[0137] Example 9

[0138] Preparation of 2-chlorodibenzo[b,d]furan

[0139]

[0140] The specific preparation process is as follows:

[0141] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 2-nitrodibenzo[b,d]furan (42.6 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 2-chlorodibenzo[b,d]furan (yield 21.8 mg, yield 54%).

[0142] The product was measured on a silica gel thin layer plate using hexane and found to have an Rf = 0.5.

[0143] The structural characterization data of the product are as follows:

[0144] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.91 (d, J=7.6Hz, 2H), 7.84 (d, J=8.0Hz, 1H), 7.56 ( d,J=8.0Hz,2H),7.46(dd,J1=J2=7.2Hz,1H),7.34(dd,J=3.7Hz,1.9Hz,2H)ppm.

[0145] 13 C NMR (100MHz, CDCl3, 25℃, δ): 156.5, 156.3, 132.7, 127.5, 123.5, 123.3, 123.1, 123.0, 121.2, 120.6, 112.3, 111.8ppm

[0146] HRMS-EI(m / z)calc'd for C 12 H7C1O + [M] + ,202.0180;found,202.0177.

[0147] Example 10

[0148] 5-Chloroisoquinoline

[0149] The specific reaction formula is as follows:

[0150]

[0151] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium persulfate (69.3 mg, 0.20 mmol, 1.0 equiv), NaCl (35.0 mg, 0.60 mmol, 3.0 equiv), 5-nitroisoquinoline (34.8 mg, 0.20 mmol, 1.0 equiv) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75 ° C for 48 hours under 390 nm LEDs irradiation. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless oily product 5-chloroisoquinoline (yield 15.6 mg, yield 48%).

[0152] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 20:1), and the Rf of the product was measured to be 0.3.

[0153] The structural characterization data of the product are as follows:

[0154] 1 H NMR (400MHz, CDCl3, 25℃, δ): 9.04–9.03(m,1H),8.16(d,J=8.0Hz,1H),7.82(d,J=7.2Hz,1H),7.72(d,J=8.0Hz,1H),7.45–7.42(m,2H)ppm.

[0155] 13 C NMR (100MHz, CDCl3, 25℃, δ): 151.0,144.4,136.5,133.4,129.6,129.5,127.0,126.5,121.9ppm

[0156] HRMS-ESI(m / z)calc'd for C9H6ClN[M+H] + ,164.0262;found,164.0264.

[0157] Embodiment 11

[0158] Preparation of N-(3,5-bis(trifluoromethoxybenzene))-5-chlorofuran-2-carboxamide

[0159] The specific reaction formula is as follows:

[0160]

[0161] The specific preparation process is as follows:

[0162] In argon, FeCl3 (5.7 mg, 0.035 mmol, 35 mol%), potassium peroxydisulfate (34.7 mg, 0.10 mmol, 1.0 equivalent), NaCl (17.5 mg, 0.30 mmol, 3.0 equivalent), N-(3,5-bis(trimethoxyphenyl)-5-nitrofuran-2-carboxamide) (36.8 mg, 0.10 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by flash column chromatography on silica gel using a hexane / ethyl acetate mixture as the eluent to give a colorless solid product, N-(3,5-bistrifluoromethylbenzene)-5-chlorofuran n-2-carboxamide (yield: 17.1 mg, 48%).

[0163] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 20:1), and the Rf of the product was measured to be 0.3.

[0164] The structural characterization data of the product are as follows:

[0165] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.29 (s, 1H), 8.19 (s, 2H), 8.65 (s, 1H), 7.29 (d, J = 3.6Hz, 1H), 6.41 (d, J = 3.6Hz, 1H) ppm.

[0166] 13 C NMR (100MHz, CDCl3, 25℃, δ): 156.1, 146.8, 139.7, 138.6, 132.5 (d, J = 33.3Hz), 123.0 (d, J = 271.1Hz), 119.7 (d, J = 3.1Hz), 118.7, 118.0 (d, J = 3.8Hz) ppm

[0167] 19 F NMR (400MHz, CDCl3, 25℃, δ): –63.1ppm

[0168] HRMS-EI(m / z)calc'd for C13 H6ClF6O2 + [M] + ,356.9986;found,356.9983.

[0169] Example 12

[0170] Preparation of 5-chloro-2-phenylpyridine

[0171] The specific reaction formula is as follows:

[0172]

[0173] The specific preparation process is as follows:

[0174] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equiv), NaCl (35.0 mg, 0.60 mmol, 3.0 equiv), 5-nitro-2-phenylpyridine (40.0 mg, 0.20 mmol, 1.0 equiv) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75 ° C for 48 hours under irradiation of 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 5-chloro-2-phenylpyridine (yield 32.5 mg, yield 86%).

[0175] On a silica gel thin layer plate, hexane-ethyl acetate was used as a developing solvent (the volume ratio of hexane to ethyl acetate was 20:1), and the Rf of the product was measured to be 0.3.

[0176] The structural characterization data of the product are as follows:

[0177] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.67 (d, J = 1.6Hz 1H), 7.99–7.98 (m, 2H), 7.74–7.67 (m, 2H), 7.53–7.44 (m, 3H) ppm.

[0178] 13 C NMR (100MHz, CDCl3, 25℃, δ): 155.6, 148.5, 138.2, 136.5, 130.6, 129.3, 128.9, 126.8, 121.1ppm

[0179] HRMS-ESI(m / z)calc'd for C11 H8ClN[M+H] + ,190.0418;found,190.0146.

[0180] Example 13

[0181] Preparation of 4,4'-(2-chloroethylene)-1,1-disubstituted dimethylbenzene

[0182] The specific reaction formula is as follows:

[0183]

[0184] The specific preparation process is as follows:

[0185] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv), 4,4'-(2-nitroethylene-1,1-disubstituted bismethylbenzene) (50.6 mg, 0.20 mmol, 1.0 equiv) were added to a reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 4,4'-(2-chloroethylene)-1,1-disubstituted bismethylbenzene (yield 31.9 mg, yield 66%).

[0186] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.3.

[0187] The structural characterization data of the product are as follows:

[0188] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.21 (s, 4H), 7.10 (s, 4H), 6.52 (s, 1H), 2.39 (s, 3H), 2.34 (s, 3H) ppm.

[0189] 13 C NMR (100MHz, CDCl3, 25℃, δ): 143.6, 138.0, 137.8, 137.5, 134.8, 129.8, 129.1, 128.9, 127.7, 114.7, 21.4, 21.2ppm

[0190] HRMS-EI(m / z)calc'd for C 16 H 15 Cl + [M] +,242.0857;found,242.0855.

[0191] Embodiment 14

[0192] Preparation of 4,4'-(2-chloroethylene)-1,1-disubstituted bismethoxybenzene

[0193] The specific reaction formula is as follows:

[0194]

[0195] The specific preparation process is as follows:

[0196] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv), 4,4'-(2-nitroethylene-1,1-disubstituted bismethoxybenzene (47.0 mg, 0.20 mmol, 1.0 equiv) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at room temperature for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 4,4'-(2-chloroethylene)-1,1-disubstituted bismethoxybenzene (yield 33.0 mg, yield 60%).

[0197] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.3.

[0198] The structural characterization data of the product are as follows:

[0199] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.27(d, J=8.0Hz, 2H), 7.14(d, J=8.8Hz, 2H), 6.92(d ,J=8.4Hz,2H),6.83(d,J=8.4Hz,2H),6.43(s,1H),3.84(s,3H),3.80(s,3H)ppm.

[0200] 13 C NMR (100MHz, CDCl3, 25℃, δ): 159.6, 159.2, 142.9, 133.1, 131.3, 130.9, 130.0, 129.1, 113.8, 113.5, 55.3, 55.2ppm

[0201] HRMS-EI(m / z)calc'd for C 16 H 15 ClO2 + [M]+ ,274.0755;found,274.0755.

[0202] Embodiment 15

[0203] The same as Example 3, except that the LED irradiation wavelength is 450 nm, and the yield of 4-chloro-1,1'-biphenyl is 75%.

[0204] Example 16

[0205] The same as Example 3, except that the LED irradiation wavelength is 365 nm, and the yield of 4-chloro-1,1'-biphenyl is 85%.

[0206] Embodiment 17

[0207] The same as Example 3, except that the LED irradiation wavelength is 295 nm, and the yield of 4-chloro-1,1'-biphenyl is 45%.

[0208] Embodiment 18

[0209] The same as Example 3, except that the LED irradiation wavelength is 255 nm, and the yield of 4-chloro-1,1'-biphenyl is 33%.

[0210] Embodiment 19

[0211] The same as Example 3, except that the catalyst used was AlCl3 (0.20 mmol), and a colorless solid product 4-chloro-1,1'-biphenyl was obtained with a yield of 85%.

[0212] Embodiment 20

[0213] The same as Example 3, except that the catalyst used was CuCl2 (0.20 mmol), and a colorless solid product 4-chloro-1,1'-biphenyl was obtained with a yield of 45%.

[0214] Embodiment 21

[0215] Preparation of 4'-chloro-4-trifluoromethyl-11'-biphenyl

[0216]

[0217] In argon, AlCl3 (26.6 mg, 0.2 mmol, 1.0 equiv.), 4'-nitro-4-trifluoromethyl-1,1'-biphenyl (39.8 mg, 0.2 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with n-hexane as the eluent to obtain a colorless solid product 4'-chloro-4-trifluoromethyl-1,1'-biphenyl (yield 20.6 mg, yield 55%).

[0218] Embodiment 22

[0219] Preparation of 4'-chloro-3-trifluoromethyl-1,1'-biphenyl

[0220]

[0221] In argon, CuCl2 (26.8 mg, 0.2 mmol, 1.0 equiv.), 4'-nitro-4-trifluoromethyl-1,1'-biphenyl (39.8 mg, 0.1 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with n-hexane as the eluent to obtain a colorless solid product 4'-chloro-4-trifluoromethyl-1,1'-biphenyl (yield 25.6 mg, yield 50%).

[0222] Embodiment 23

[0223] Preparation of 3,4-dichlorobenzophenone

[0224]

[0225] In air, 3-chloro-4-nitro-benzophenone (1.0466 g, 4.0 mmol, 1.0 equivalent), FeCl3 (0.2271 g, 1.4 mmol, 35 mol%), Oxone (1.3853 g, 4.0 mol, 1.0 equivalent), NaCl (0.7013 g, 12.0 mmol, 3.0 equivalent) and 15.0 mL of acetonitrile were added to a 50 mL round-bottom flask to obtain a reaction mixture, and then the reaction mixture was stirred at 75 ° C. under 390 nm LEDs illumination and the resulting solution was detected by TLC. The reaction mixture was then transferred to a flask with ethyl acetate, the volatiles were removed under vacuum, and the residue was purified by silica gel flash column chromatography, eluting with hexane / ethyl acetate to obtain the product 3,4-dichlorobenzophenone (yield 0.8506 g, yield 85%).

[0226] Embodiment 24

[0227] Preparation of 6-chloro-2-methylbenzoxazole:

[0228] The specific reaction formula is as follows:

[0229]

[0230] The specific preparation process is as follows:

[0231] In argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 2-methyl-6-nitrobenzoxazole (0.20 m mol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75 ° C for 24 hours under 390 nm LED irradiation. The mixture was then transferred to a flask filled with ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture (hexane to ethyl acetate volume ratio 20:1) to obtain a colorless solid compound 6-chloro-2-methylbenzoxazole (yield 18.0 mg, yield 54%).

[0232] On a silica gel thin layer plate using hexane / ethyl acetate (20:1) as a developing solvent, the product was measured to have an Rf of 0.5.

[0233] The structural characterization data of the product are as follows:

[0234] 1H NMR (400MHz, CDCl3, 25℃, δ): 7.53 (d, J = 8.8 Hz, 1H), 7.46 (s, 1H), 7.26 (d, J = 8.4 Hz, 1H), 2.62 (s, 3H) ppm.

[0235] 1 3C NMR (100MHz, CDCl3, 25℃, δ): 164.5, 151.1, 140.2, 130.1, 124.7, 119.9, 110.9, 14.5ppm.

[0236] HRMS-EI(m / z)calc'd for C8H6ClNO + [M] + ;167.0132,found,167.0129.

[0237] Embodiment 25

[0238] Same as Example 24, except that the chloride salt NaCl was replaced by LiCl. The yield of 6-chloro-2-methylbenzoxazole was 40%.

[0239] Embodiment 26

[0240] Same as Example 24, except that the chloride salt NaCl was replaced by MgCl2. The yield of 6-chloro-2-methylbenzoxazole was 13%.

[0241] Embodiment 27

[0242] Same as Example 24, except that the reaction temperature was room temperature. The yield of 6-chloro-2-methylbenzoxazole was 20%.

[0243] Embodiment 28

[0244] Same as Example 24, except that the reaction temperature was 55° C. The yield of 6-chloro-2-methylbenzoxazole was 40%.

[0245] Embodiment 29

[0246]

[0247] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4-nitro-1,1'-biphenyl (0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at room temperature for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 4-chloro-1,1'-biphenyl with a yield of 77%.

[0248] Embodiment 30

[0249]

[0250] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4'-nitro-2-trifluoromethoxy-1,1'-biphenyl (0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at room temperature for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless oily product 4'-chloro-2-trifluoromethoxy-1,1'-biphenyl with a yield of 72%.

[0251] Embodiment 31

[0252]

[0253] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4'-nitro-4-trifluoromethyl-1,1'-biphenyl (0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at room temperature for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 4'-chloro-4-trifluoromethyl-1,1'-biphenyl with a yield of 63%.

[0254] Embodiment 32

[0255]

[0256] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4'-nitro-3-trifluoromethyl-1,1'-biphenyl (0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at room temperature for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 4'-chloro-3-trifluoromethyl-1,1'-biphenyl with a yield of 77%.

[0257] Embodiment 33

[0258] Preparation of 2-chloro-1,1'-biphenyl

[0259]

[0260] The specific preparation process is as follows:

[0261] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 2-nitro-1,1'-biphenyl (39.8 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product, chloro-1,1'-biphenyl (yield 31.6 mg, yield 84%).

[0262] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.4.

[0263] The structural characterization data of the product are as follows:

[0264] NMR Spectroscopy:

[0265] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.54–7.47(m,5H),7.45–7.42(m,1H),7.41–7.31(m,3H)ppm.

[0266] 13 C NMR (100MHz, CDCl3, 25℃, δ): 140.6, 139.5, 132.6, 131.5, 130.0, 129.6, 128.6, 128.2, 127.7, 126.9ppm.

[0267] HRMS-EI(m / z)calc'd for C 12 H8Cl + [M] + ,188.0387;found,188.0381.

[0268] Embodiment 34

[0269] Preparation of 1-Chloroanthraquinone-9,10-dione

[0270]

[0271] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 1-nitroanthraquinone-9,10-dione (50.6 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain an orange solid product 1-chloroanthraquinone-9,10-dione (yield 16.9 mg, yield 35%).

[0272] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.4.

[0273] The structural characterization data of the product are as follows:

[0274] NMR Spectroscopy:

[0275] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.32–8.25 (m, 3H), 7.84–7.66 (m, 3H), 7.68 (dd, J1=J2=8.0Hz, 1H)ppm.

[0276] 13 C NMR (100MHz, CDCl3, 25℃, δ): 182.2, 181.8, 137.8, 136.0, 135.1, 134.6, 134.5, 133.9, 133.7, 132.3, 129.6, 127.6, 126.8ppm

[0277] HRMS-EI(m / z)calc'd for C 14 H7ClO2 + [M] + ,242.0214;found,242.0217.

[0278] Embodiment 35

[0279] Preparation of 4-chloroacetophenone

[0280]

[0281] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4-nitroacetophenone (50.6 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless liquid product 4-chloroacetophenone (yield 25.9 mg, yield 84%).

[0282] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 60:1) was used as a developing solvent, and the Rf of the product was measured to be 0.2.

[0283] The structural characterization data of the product are as follows:

[0284] NMR Spectroscopy:

[0285] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.90 (d, J = 8.4Hz, 2H), 7.44 (d, J = 8.4Hz, 2H), 2.60 (s, 3H) ppm.

[0286] 13 C NMR (100MHz, CDCl3, 25℃, δ): 196.9, 139.6, 135.4, 129.8, 128.9, 26.6ppm.

[0287] HRMS-EI(m / z)calc'd for C8H7ClO + [M] + ,154.0180;found,154.0177.

[0288] Embodiment 36

[0289] Preparation of Benzyl 3-Chlorobenzoate

[0290]

[0291] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4-nitrobenzoic acid benzyl ester (33.0 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless liquid product 4-chlorobenzoic acid benzyl ester (yield 20.2 mg, yield 41%).

[0292] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0293] The structural characterization data of the product are as follows:

[0294] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.10 (d, J=7.6Hz, 2H), 7.57 (dd, J1=J2=7.2Hz, 1 H),7.53–7.50(m,1H),7.47–7.41(m,3H),7.30–7.28(m,2H),5.48(s,2H)ppm.

[0295] 13 C NMR (100MHz, CDCl3, 25℃, δ): 166.3, 133.8, 133.7, 133.2, 129.9, 129.8, 129.7, 129, 6, 129, 5, 128.5, 127.0, 64.1ppm

[0296] HRMS-ESI(m / z)calc'd for C 14 H 11 ClO2[M+Na] + ,269.0340;found,260.0338.

[0297] Embodiment 37

[0298] 2-Chlorobenzoic acid phenyl ester

[0299]

[0300] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 4-nitrobenzoic acid phenyl ester (33.0 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless liquid product 4-chlorobenzoic acid phenyl ester (yield 36.6 mg, yield 79%).

[0301] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0302] The structural characterization data of the product are as follows:

[0303] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.24(d,J=7.2Hz,2H),7.64(dd,J1=J2=7.2Hz,1H),7.54–7.47(m,3H),7.35–7,26(m,2H),7.24–7.20(m,1H)ppm.

[0304] 13 C NMR (100MHz, CDCl3, 25℃, δ): 164.3, 147.3, 133.9, 130.4, 128.9, 128.7, 127.8, 127.1, 127.0, 123.9ppm. One carbon is missing because of overlap.

[0305] HRMS-EI(m / z)calc'd for C 13 H9ClO2 + [M] + ,232.0286;found,232.0284.

[0306] Embodiment 38

[0307] Preparation of 1-chloro-diphenyl ether

[0308]

[0309] The specific preparation process is as follows:

[0310] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equivalent), 4-nitrodiphenyl ether (32.4 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless liquid product 1-chlorodiphenyl ether (yield 32.6 mg, yield 80%).

[0311] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.2.

[0312] The structural characterization data of the product are as follows:

[0313] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.26 (dd, J1=J2=8.4Hz, 2H), 7.22–7.19 (m, 2H), 7.04 (dd, J1=J2=7.6Hz, 1H), 6.91 (d, J=8.4Hz, 2H), 6.87–6.83 (m, 2H)ppm.

[0314] 13 C NMR (100MHz, CDCl3, 25℃, δ): 156.9, 156.0, 129.9, 129.7, 128.2, 123.7, 120.1, 119.0ppm.

[0315] HRMS-EI(m / z)calc'd for C 12 H9ClO + [M] + ,204.0036;found,204.0031.

[0316] Embodiment 39

[0317] Preparation of 3-(4-chlorophenyl)thiophene

[0318]

[0319] The specific preparation process is as follows:

[0320] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 3-(4-nitro)thiophene (41.0 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 3-(4-chlorophenyl)thiophene (yield 32.6 mg, yield 80%).

[0321] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 50:1) was used as a developing solvent, and the Rf of the product was measured to be 0.5.

[0322] The structural characterization data of the product are as follows:

[0323] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.52–7.50 (m, 2H), 7.58 (d, J = 8.4Hz, 2H), 7.40 (d, J = 8.4Hz, 2H), 7.35 (s, 1H) ppm.

[0324] 13 C NMR (100MHz, CDCl3, 25℃, δ): 141.1,134.3,132.9,129.0,127.7,126.6,126.2,120.6ppm

[0325] HRMS-EI(m / z)calc'd for C 10 H7C1 + [M] + ,193.9952;found,193.9948.

[0326] Embodiment 40

[0327] Preparation of 5-(4-chlorobenzene)oxazole:

[0328]

[0329] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium persulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 5-(4-nitrobenzene) oxazole (38.0 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LED irradiation. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 5-(4-chlorobenzene) oxazole (yield 24.0 mg, yield 67%).

[0330] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 5:1) was used as a developing solvent, and the Rf of the product was measured to be 0.5.

[0331] The structural characterization data of the product are as follows:

[0332] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.93 (s, 1H), 7.58 (d, J = 8.4Hz, 2H), 7.87 (d, J = 8.4Hz, 2H), 7.35 (s, 1H) ppm.

[0333] 13 C NMR (100MHz, CDCl3, 25℃, δ): 150.7, 134.5, 129.2, 126.2, 125.6, 121.8, 100.0ppm

[0334] HRMS-ESI(m / z)calc'd for C9H6ClNO[M+H] + ,180.0211;found,180.0209.

[0335] Embodiment 41

[0336] Preparation of N-(2,4-dichlorophenyl)benzamide

[0337]

[0338] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), N-(2-chloro-4-nitrobenzene)benzamide (55.2 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product N-(2,4-dichlorobenzene)benzamide (yield 35.5 mg, yield 67%).

[0339] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0340] The structural characterization data of the product are as follows:

[0341] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.56 (d, J=8.8Hz, 1H), 8.42 (s, 1H), 7,93 (d, J=7.6Hz, 2H), 7.62 (dd, J1=J2=7.2Hz,1H),7.55(dd,J1=J2=7.6Hz,2H),7.45(d,J=2.0Hz,1H),7.33(d,J=2.0Hz,1H)ppm.

[0342] 13 C NMR (100MHz, CDCl3, 25℃, δ): 165.2, 134.3, 133.5, 132.4, 129.2, 129.0, 128.8, 128.1, 127.1, 123.5, 122.2ppm.

[0343] HRMS-ESI(m / z)calc'd for C 13 H9Cl2NO[M+H] + ,266.0134;found,266.0137.

[0344] Embodiment 42

[0345] Preparation of 4-chloro-2-((2,4-dichlorobenzene)formamide)benzoic acid phenyl ester

[0346]

[0347] As shown in the reaction formula, FeCl3 (5.7 mg, 0.035 mmol, 35 mol%), potassium peroxydisulfate (34.7 mg, 0.10 mmol, 1.0 equivalent), NaCl (17.5 mg, 0.30 mmol, 3.0 equivalent), 4-chloro-2-((2-chloro-4-nitrobenzene)formamide)benzoic acid phenyl ester (43.0 mg, 0.10 mmol, 1.0 equivalent) were added to a reaction bottle in argon, and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by flash column chromatography on silica gel using a hexane / ethyl acetate mixture as the eluent to give phenyl 4-chloro-2-((2,4-dichlorobenzene)formamido)benzoate as a colorless solid (yield: 22.7 mg, 54%).

[0348] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0349] The structural characterization data of the product are as follows:

[0350] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.59 (s, 1H), 8.38 (d, J = 9.2Hz, 1H), 8.18 (d, J = 7.6Hz, 2H), 7.98 (d, J = 1.6Hz,1H),7.66(dd,J1=J2=7.2Hz,1H),7.56–7.49(m,3H),7.28(s,1H),7.23(d,J=8.4Hz,2H)ppm.

[0351] 13 C NMR (100MHz, CDCl3, 25℃, δ): 164.9, 162.0, 146.8, 134.5, 133.1, 132.8, 132.4, 130 .6,129.7,129.3,128.9,128.7,128.3,127.9,125.0,123.6,122.8ppm.onecarbon is missing because of overlap.

[0352] HRMS-FIA(m / z)calc'd for C 20 H 12 Cl3NO3[M+H] +,419.9956;found,419.9955.

[0353] Embodiment 43

[0354] Preparation of 1-chloro-2-methylnaphthol

[0355]

[0356] The specific preparation process is as follows:

[0357] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 2-methyl-1-nitronaphthol (32.4 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product, 1-chloro-2-methylnaphthol (yield 18.6 mg, yield 53%).

[0358] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 80:1) was used as a developing solvent, and the Rf of the product was measured to be 0.2.

[0359] The structural characterization data of the product are as follows:

[0360] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.28 (d, J = 8.4Hz, 1H), 7.79 (d, J = 8.0Hz, 1H), 7.66 (d, J = 8.4Hz ,1H),7.58–7.54(m,1H),7.46(dd,J1=J2=7.6Hz,1H)7.33(d,J=8.4Hz,1H),2.57(s,3H)ppm.

[0361] 13 C NMR (100MHz, CDCl3, 25℃, δ): 133.5, 133.0, 131.2, 130.7, 128.8, 128.0, 127.0, 126.5, 125.7, 124.2, 20.9ppm.

[0362] HRMS-EI(m / z)calc'd for C 11 H9Cl + [M] + ,176.0387;found,176.0383.

[0363] Embodiment 44

[0364] Preparation of 2-chlorofluorene

[0365]

[0366] The specific preparation process is as follows:

[0367] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 2-nitrofluorene (42.2 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 2-chlorofluorene (yield 21.6 mg, yield 54%).

[0368] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.5.

[0369] The structural characterization data of the product are as follows:

[0370] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.77(d,J=7.2Hz,1H),7.71(d,J=8.0Hz,1H),7.58–7.52(m,2H),7.44–7.34(m,2H),3.90(s,2H)ppm.

[0371] 13 C NMR (100MHz, CDCl3, 25℃, δ): 143.2,141.7,126.7,126.7,125.0,119.9,36.9.ppm

[0372] HRMS-EI(m / z)calc'd for C 13 H9Cl + [M] + ,200.0387;found,200.0385.

[0373] Embodiment 45

[0374] Preparation of 3-chlorophenanthrene

[0375]

[0376] The specific preparation process is as follows:

[0377] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 3-nitrophenanthrene (42.2 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 3-chlorophenanthrene (yield 36.9 mg, yield 87%).

[0378] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.6.

[0379] The structural characterization data of the product are as follows:

[0380] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.65–8.61 (m, 2.5H), 8.53–8.51 (m, 1.0H), 7.88–7.73 (m, 2.5H), 7.70–7.47 (m, 5.2H)ppm.

[0381] 13 C NMR (100MHz, CDCl3, 25℃, δ): 132.7, 131.9, 131.7, 131.4, 130.6, 130.0, 129.5, 129.4, 129.3, 128.7, 128.6, 128.3, 1 27.9,127.4,127.3,127.1,127.1,127.0,126.9,126.5,126.4,125.3,123.0,122.9,122.7,122.5,122.4,121.7ppm

[0382] HRMS-ESI(m / z)calc'd for C 14 H9Cl[M+K] + ,251.0024;found,250.9984.

[0383] Embodiment 46

[0384] Preparation of 5-chloroisoquinoline:

[0385]

[0386] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxydisulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 5-nitroisoquinoline (34.8 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 5-chloroisoquinoline (yield 14.0 mg, yield 43%).

[0387] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0388] The structural characterization data of the product are as follows:

[0389] 1 H NMR (400MHz, CDCl3, 25℃, δ): 9.28 (s, 1H), 8.66 (d, J = 5.6Hz, 1H), 8.66 (d, J = 5.6Hz, 1H), 8.03 ( d,J=5.6Hz,1H),7.92(d,J=8.0Hz,1H),7.79(d,J=7.2Hz,1H),7.55(dd,J1=J2=7.6Hz,1H)ppm.

[0390] 13 C NMR (100MHz, CDCl3, 25℃, δ): 152.6, 144.3, 133.7, 131.0, 130.3, 129.5, 127.3, 126.7, 116.9ppm

[0391] HRMS-ESI(m / z)calc'd for C9H6ClN[M+H] + ,164.0262;found,164.0264.

[0392] Embodiment 47

[0393] Preparation of 3,4-dichloroquinoline:

[0394]

[0395] The specific preparation process is as follows:

[0396] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equivalent), 4-chloro-3-nitroquinoline (32.4 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 3,4-dichloroquinoline (yield 16.2 mg, yield 41%).

[0397] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0398] The structural characterization data of the product are as follows:

[0399] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.85 (s, 1H), 8.22 (d, J = 8.4Hz, 1H), 8.11 (d, J = 8.4Hz, 1H), 7.77 (dd, J1 = J2 = 7.2Hz, 1H), 7.69 (dd, J1 = J2 = 7.6Hz, 1H) ppm.

[0400] 13 C NMR (100MHz, CDCl3, 25℃, δ): 149.6, 146.9, 139.3, 130.2, 130.0, 128.6, 127.3, 126.9, 124.2ppm

[0401] HRMS-EI(m / z)calc'd for C9H5Cl2N+[M] + ,196.9794;found,196.9791.

[0402] Embodiment 48

[0403] Preparation of 3-chloro-1-phenylpyrrole:

[0404]

[0405] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium persulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 3-nitro-1-phenylpyrrole (37.8 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 3-nitro-1-phenylpyrrole (yield 15.3 mg, yield 43%).

[0406] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 20:1) was used as the developing solvent, and the Rf of the product was measured to be 0.3.

[0407] The structural characterization data of the product are as follows:

[0408] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.83(d, J=2.4Hz, 1H), 7.63(d, J=8.0Hz, 2H), 7.44(d d, J1=J2=7.6Hz, 2H), 7.29 (dd, J1=J2=7.6Hz, 1H), 6.37 (dd, J1=J2=2.4Hz, 1H)ppm.

[0409] 13 C NMR (100MHz, CDCl3, 25℃, δ): 141.6, 139.6, 129.5, 128.5, 126.3, 118.9, 107.2ppm

[0410] HRMS-ESI(m / z)calc'd for C9H7ClN2[M+H] + ,179.0371;found,179.0376.

[0411] Embodiment 49

[0412] Preparation of 5-chloroformyl-5H-dibenzo[a,d][7]annulene:

[0413]

[0414] The specific preparation process is as follows:

[0415] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 5-nitromethylene-10,11-dihydro-5H-dibenzo[a,d][7]annulene (50.2 mg, 0.20 mmol, 1.0 equiv.) were added to a reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product, 5-chloromethylenyl-5H-dibenzo[a,d][7]annulene (yield 16.2 mg, yield 34%).

[0416] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.3.

[0417] The structural characterization data of the product are as follows:

[0418] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.48–7.43 (m, 1H), 7.42–7.28 (m, 7H), 6.92–6.83 (dd, J = 12.0Hz, 10.8Hz, 2H), 6.21 (s, 1H) ppm.

[0419] 13 C NMR (100MHz, CDCl3, 25℃, δ): 143.0, 138.6, 134.8, 134.5, 134.2, 131.2, 130.6, 129.3, 129.0, 128.8, 128.7, 128.2, 127.9, 127.8, 127.6, 118.3ppm

[0420] HRMS-EI(m / z)calc'd for C 16 H 11 Cl + [M] + ,238.0544;found,238.0543.

[0421] Embodiment 50

[0422] Preparation of 2-chloro-1,1'-diphenylethylene:

[0423]

[0424] The specific preparation process is as follows:

[0425] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 2-nitro-1,1'-stilbene 50.2 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 2-chloro-1,1'-stilbene (yield 34.3 mg, yield 80%).

[0426] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.5.

[0427] The structural characterization data of the product are as follows:

[0428] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.43–7.35(m,3H),7.34–7.29(m,5H),7.23–7.19(m,2H),6.59(s,1H)ppm.

[0429] 13 C NMR (100MHz, CDCl3, 25℃, δ): 143.9, 140.1, 137.6, 129.9, 128.5, 128.2, 128.1, 128.0, 127.8, 115.9ppm.

[0430] HRMS-EI(m / z)calc'd for C 14 H 11 Cl + [M] + ,214.0544;found,214.0541.

[0431] Embodiment 51

[0432] Preparation of 2,4,4-chloro-1,1'-stilbene:

[0433]

[0434] The specific preparation process is as follows:

[0435] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 4,4'-chloro-2-nitro-1,1'-stilbene (50.2 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product 2,4,4;-chloro-1,1'-stilbene (yield 42.8 mg, yield 76%).

[0436] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.5.

[0437] The structural characterization data of the product are as follows:

[0438] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.38 (d, J = 8.4Hz, 2H), 7.29–7.25 (m, 4H), 7.11 (d, J = 8.4Hz, 2H), 6.58 (s, 1H) ppm.

[0439] 13 C NMR (100MHz, CDCl3, 25℃, δ): 141.8, 138.2, 135.5, 134.4, 134.2, 131.3, 129.0, 128.8, 128.7, 116.9ppm.

[0440] HRMS-EI(m / z)calc'd for C 14 H9Cl3 + [M] + ,281.9764;found,281.9762.

[0441] Embodiment 52

[0442] Preparation of 2-chloro-4,4'-fluoro-1,1'-stilbene:

[0443]

[0444] The specific preparation process is as follows:

[0445] In argon, FeCl3 (32.4 mg, 0.20 mmol, 1.0 equiv.), 4,4'-fluoro-2-nitro-1,1'-stilbene (50.2 mg, 0.20 mmol, 1.0 equiv.) were added to the reaction flask, and then 2.5 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at a reaction temperature of 75°C for 48 hours under irradiation with 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography with hexane as the eluent to obtain a colorless solid product, 2-chloro-4,4'-fluoro-1,1'-stilbene (yield 31.0 mg, yield 62%).

[0446] The product was measured on a silica gel thin layer plate using hexane as the developing solvent, and Rf = 0.5.

[0447] The structural characterization data of the product are as follows:

[0448] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.31–7.27(m,2H), 7.18–7.14(m,2H), 7.09(dd,J1=J2=8.4Hz,2H), 7.00(dd,J1=J2=8.8Hz,2H), 6.52(s,1H)ppm.

[0449] 13 C NMR (100MHz, CDCl3, 25℃, δ): 163.8(d,J=35.0Hz), 161.3(d,J=34.6Hz), 142.0, 136.1(d,J=3.3Hz), 134.7(d,J= 284.9Hz), 133.1 (d, J = 3.4Hz), 132.5 (d, J = 8.1Hz), 129.4 (d, J = 8.1Hz), 115.9, 115.6, 115.5, 115.4, 115.3ppm.

[0450] 19 F NMR (400MHz, CDCl3, 25℃, δ): –113.1, –113.4ppm

[0451] HRMS-EI(m / z)calc'd for C 14 H9Cl3F2 + [M] + ,250.0355;found,250.0353.

[0452] Embodiment 53

[0453]

[0454] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium persulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), nitroaromatic compound shown in I-1 (55.6 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under irradiation of 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product of the chlorinated aromatic compound shown in formula II-2 (yield 37.9 mg, yield 71%).

[0455] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate is 3:1) was used as a developing solvent, and the Rf of the product was measured to be 0.4.

[0456] The structural characterization data of the product are as follows:

[0457] 1 H NMR (400MHz, CDCl3, 25℃, δ): 8.61 (d, J = 4.4Hz, 1H), 8.49 (d, J = 7.6Hz, 1H), 7.51 (d, J = 8.0Hz, 1H), 7.45–7.42 (m, 1H), 7.38–7.25 (m, 3H) ppm.

[0458] 13 C NMR (100MHz, CDCl3, 25℃, δ): 161.8, 152.8, 150.9, 146.6, 141.1, 130.5, 128.0, 127.7, 126.8, 125.4, 123.7, 122.3ppm.

[0459] Embodiment 54

[0460]

[0461] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), nitroaromatic compound (56.6 mg, 0.20 mmol, 1.0 equivalent) shown in formula I-2 are added to the reaction bottle, and then 1.0 mL of acetonitrile is added to obtain a reaction mixture. The reaction mixture is then stirred at 75 ° C for 48 hours under irradiation with 390 nm LEDs. The mixture is then transferred to a flask containing ethyl acetate, and the volatiles are removed under vacuum to obtain a residue. The residue is purified by silica gel flash column chromatography, and the eluent is a hexane / ethyl acetate mixture to obtain a colorless solid product of the chlorinated aromatic compound shown in formula II-2 (yield 32.7 mg, yield 60%).

[0462] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 10:1) was used as a developing solvent, and the Rf of the product was measured to be 0.3.

[0463] The structural characterization data of the product are as follows:

[0464] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.80 (s, 1H), 7.52–7.48 (m, 2H), 7.37–7.33 (m, 3H), 7.25–7.23 (m, 1H), 7.72 (d, J = 8.0Hz, 1H), 7.64 (d, J = 8.0Hz, 1H) ppm.

[0465] 13 C NMR (100MHz, CDCl3, 25℃, δ): 156.9, 156.2, 146.4, 144.1, 130.5, 128.4, 128.0, 127.5, 127.0, 126.9, 124.1, 123.8, 123.2, 116.2, 112.6ppm.

[0466] Embodiment 55

[0467] Preparation of 2,3,6-trichloropyridine:

[0468]

[0469] As shown in the reaction formula, in argon, FeCl3 (11.4 mg, 0.070 mmol, 35 mol%), potassium peroxysulfate (69.3 mg, 0.20 mmol, 1.0 equivalent), NaCl (35.0 mg, 0.60 mmol, 3.0 equivalent), 2,6-dichloro-3-nitropyridine (38.4 mg, 0.20 mmol, 1.0 equivalent) were added to the reaction bottle, and then 1.0 mL of acetonitrile was added to obtain a reaction mixture. The reaction mixture was then stirred at 75 ° C for 48 hours under 390 nm LEDs. The mixture was then transferred to a flask containing ethyl acetate, and the volatiles were removed under vacuum to obtain a residue. The residue was purified by silica gel flash column chromatography, and the eluent was a hexane / ethyl acetate mixture to obtain a colorless solid product 2,3,6-trichloropyridine (yield 25.7 mg, yield 71%).

[0470] On a silica gel thin layer plate, hexane / ethyl acetate (the volume ratio of hexane to ethyl acetate was 40:1) was used as a developing solvent, and the Rf of the product was measured to be 0.3.

[0471] The structural characterization data of the product are as follows:

[0472] 1 H NMR (400MHz, CDCl3, 25℃, δ): 7.75 (d, J = 8.4Hz, 1H), 7.26 (d, J = 8.4Hz, 1H) ppm.

[0473] 13 C NMR (100MHz, CDCl3, 25℃, δ): 148.3, 148.1, 140.8, 129.5, 124.0, 122.9ppm.

[0474] Comparative Example 1

[0475] Same as Example 24, except that the chloride salt NaCl is replaced by the non-metal chloride salt TBAC. No 6-chloro-2-methylbenzoxazole is generated.

[0476] Comparative Example 2

[0477] The same as Example 24, except that there is no LED irradiation. Finally, no 6-chloro-2-methylbenzoxazole is generated.

[0478] Although the embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons, characterized in that: The method comprises: reacting the nitroaromatic hydrocarbon represented by formula I and the metal chloride salt in an organic solvent at 25 to 75° C. under the catalysis of a metal salt catalyst and under the irradiation of light with a wavelength of 365 nm to 450 nm to obtain the chlorinated aromatic compound represented by formula II: Wherein, Ar is one of a substituted or unsubstituted aromatic group and a heteroaromatic group; The substituent of the substituted aromatic group or heteroaromatic group is selected from one or more of halogen, cyano, hydroxyl, trifluoromethyl, alkyl, alkoxy, aryloxy, acyloxy, ester, acyl, thienyl, oxazolyl, phenyl or amide; The aromatic group is selected from one of phenyl, styryl or condensed ring aromatic group, and the heteroaromatic group is selected from one of furanyl, pyridyl, pyrazole, benzoxazolyl, benzofuranyl, dibenzofuranyl, isoquinolyl or quinolyl; The organic solvent is acetonitrile; The metal salt catalyst is selected from one or more of FeCl3, CuCl2 or AlCl3; The metal chloride salt is selected from one of NaCl and LiCl; The molar ratio of the nitroaromatic hydrocarbon, the metal chloride and the metal salt catalyst is 1:(0.8-3):(0.2-0.35).

2. The method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons according to claim 1, characterized in that: The metal salt catalyst is FeCl3.

3. The method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons according to claim 1, characterized in that: The reaction temperature is 55-75°C.

4. The method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons according to any one of claims 1 to 3, characterized in that: During the reaction, an oxidizing agent, oxone, was also added.

5. The method for preparing chlorinated aromatic compounds by photoinduced denitration and chlorination of nitroaromatic hydrocarbons according to claim 4, characterized in that: The molar ratio of the nitroaromatic hydrocarbon to the oxidant is 1:(0.35-3).

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