阅读说明：本技术 一种2-(2-苯基-2h-吲唑-3-基)乙酸酯类化合物的水相光催化制备方法 (Water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazole-3-yl) acetate compounds ) 是由 姜玉钦 赵璐 马春华 张赖 陈希雅 尚林春 何兴 于 2021-09-02 设计创作，主要内容包括：本发明公开了一种2-(2-苯基-2H-吲唑-3-基)乙酸酯类化合物的水相光催化制备方法,属于有机合成技术领域。本发明的技术方案要点为：以2-苯基-2H-吲唑类化合物和溴乙酸乙酯为起始原料,在添加剂、氧化剂和催化剂的作用下,以水作溶剂,在空气条件下于室温白光光照反应,反应结束后用乙酸乙酯萃取反应液,旋去有机相,经柱层析分离得到目标产物2-(2-苯基-2H-吲唑-3-基)乙酸酯类化合物。本发明的制备方法操作简便安全、反应条件温和,且该方法的光源为可见光,绿色无公害,催化剂和反应介质对环境也较友好,本发明合成目标产物的收率相对较高。(The invention discloses a water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazole-3-yl) acetate compounds, belonging to the technical field of organic synthesis. The technical scheme provided by the invention has the key points that: the method comprises the steps of taking 2-phenyl-2H-indazole compounds and ethyl bromoacetate as initial raw materials, taking water as a solvent under the action of an additive, an oxidant and a catalyst, carrying out white light illumination reaction at room temperature under the condition of air, extracting a reaction solution by using ethyl acetate after the reaction is finished, removing an organic phase by spinning, and carrying out column chromatography separation to obtain the target product 2- (2-phenyl-2H-indazol-3-yl) acetate compounds. The preparation method is simple, convenient and safe to operate, mild in reaction conditions, green and pollution-free due to visible light serving as a light source, environment-friendly due to the catalyst and the reaction medium, and relatively high in yield of the synthesized target product.)

1. A water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazol-3-yl) acetate compounds is characterized by comprising the following steps: the method comprises the steps of taking a 2-phenyl-2H-indazole compound and ethyl bromoacetate as initial raw materials, taking water as a solvent under the action of an additive, an oxidant and a catalyst, carrying out white light illumination reaction at room temperature under the condition of air, extracting a reaction solution by using ethyl acetate after the reaction is finished, removing an organic phase, and carrying out column chromatography separation to obtain a target product, namely the 2- (2-phenyl-2H-indazol-3-yl) acetate compound, wherein the additive is potassium ethyl xanthate, the oxidant is lauroyl peroxide, the catalyst is 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride, the structural formula of the 2-phenyl-2H-indazole compound is shown as a formula A, the structural formula of ethyl bromoacetate is shown as a formula B, and the structural formula of the 2- (2-phenyl-2H-indazol-3-yl) acetate is shown as a formula B The structural formula of the compound is shown as formula C:

in the formula R¹Is H, C_1-5Alkyl radical, C_1-5Alkoxy, trifluoromethyl, F, Cl, Br or I, R²Is phenyl or substituted phenyl, the substituent on the benzene ring of the substituted phenyl is monobasic substitution or binary substitution, and the substituent on the benzene ring of the substituted phenyl is C_1-5Alkyl radical, C_1-5Alkoxy, trifluoromethyl, F, Cl, Br or I.

2. The aqueous phase photocatalytic preparation method of 2- (2-phenyl-2H-indazol-3-yl) acetate compounds according to claim 1, characterized in that the specific structural formula of the 2- (2-phenyl-2H-indazol-3-yl) acetate compounds is as follows:

3. the method for preparing 2- (2-phenyl-2H-indazol-3-yl) acetate compounds according to claim 1, characterized in that: the feeding molar ratio of the 2-phenyl-2H-indazole compound to the ethyl bromoacetate to the additive to the catalyst to the oxidant is 1:1-3:1-3:0.01-0.08: 1-2.5.

4. The method for preparing 2- (2-phenyl-2H-indazol-3-yl) acetate compounds by aqueous phase photocatalysis according to claim 1, wherein the reaction equation in the preparation process of the 2- (2-phenyl-2H-indazol-3-yl) acetate compounds is as follows:

the catalyst 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride has a structural formula as follows:

5. the method for preparing 2- (2-phenyl-2H-indazol-3-yl) acetate compounds according to claim 1, characterized in that: the white light source is a white LED lamp with the power of 10W.

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazole-3-yl) acetate compounds.

Background

By forming hydrogen bonding and hydrophobic interactions with the target, 2H-indazoles become a parent nucleus for widespread use in pharmaceuticals and bioactive compounds. For example: nilapari, an oral small molecule inhibitor of the poly (ADP-ribose) polymerase (PARP) enzyme, and the third generation Tyrosine Kinase Inhibitor (TKI) pazopanib, all have this parent nucleus (J.Med.chem.,2015,58, 3302-. Therefore, the structural modification of 2H-indazole is an important direction for research of medicinal chemistry and is a new hot spot for research of organic chemistry.

In recent years, structurally diverse derivatives of 2H-indazoles have been synthesized by direct free radical addition (adv. Synth. Catal.,2020,362, 3768-3794). However, no literature report is available on the method for directly synthesizing 2- (2-phenyl-2H-indazol-3-yl) acetate compounds by using 2H-indazole as a raw material. Therefore, the development of a preparation method of the 2- (2-phenyl-2H-indazol-3-yl) acetate compound which is catalyzed by visible light, does not participate in transition metal and takes water as a solvent has important significance.

Disclosure of Invention

The invention aims to solve the technical problem of providing a water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazole-3-yl) acetate compounds, and aims to solve the problems of environmental pollution, equipment corrosion and the like caused by the existing synthesis method of 2- (2-phenyl-2H-indazole-3-yl) acetate compounds.

The invention adopts the following technical scheme for solving the technical problems:

a water-phase photocatalytic preparation method of 2- (2-phenyl-2H-indazol-3-yl) acetate compounds is characterized by comprising the following steps: the method comprises the steps of taking a 2-phenyl-2H-indazole compound and ethyl bromoacetate as initial raw materials, taking water as a solvent under the action of an additive, an oxidant and a catalyst, carrying out white light illumination reaction at room temperature under the condition of air, extracting a reaction solution by using ethyl acetate after the reaction is finished, removing an organic phase, and carrying out column chromatography separation to obtain a target product, namely the 2- (2-phenyl-2H-indazol-3-yl) acetate compound, wherein the additive is potassium ethyl xanthate, the oxidant is lauroyl peroxide, the catalyst is 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride, the structural formula of the 2-phenyl-2H-indazole compound is shown as a formula A, the structural formula of ethyl bromoacetate is shown as a formula B, and the structural formula of the 2- (2-phenyl-2H-indazol-3-yl) acetate is shown as a formula B The structural formula of the compound is shown as formula C:

in the formula R¹Is H, C_1-5Alkyl radical, C_1-5Alkoxy, trifluoromethyl, F, Cl, Br or I, R²Is phenyl or substituted phenyl, the substituent on the benzene ring of the substituted phenyl is monobasic substitution or binary substitution, and the substituent on the benzene ring of the substituted phenyl is C_1-5Alkyl radical, C_1-5Alkoxy, trifluoromethyl, F, Cl, Br or I.

Further, the specific structural formula of the 2- (2-phenyl-2H-indazol-3-yl) acetate compound is as follows:

further limiting, the feeding molar ratio of the 2-phenyl-2H-indazole compound, ethyl bromoacetate, the additive, the catalyst and the oxidant is 1:1-3:1-3:0.01-0.08: 1-2.5.

Further, the reaction equation in the preparation process of the 2- (2-phenyl-2H-indazol-3-yl) acetate compound is as follows:

the catalyst 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride has a structural formula as follows:

further, the white light source is a white LED lamp with power of 10W.

Compared with the prior art, the invention has the following advantages and beneficial effects: compared with the prior art, the preparation method does not need to use a transition metal catalyst or a traditional volatile organic solvent, but uses green solvent water as a reaction medium, uses an organic photosensitizer as a catalyst under the catalysis of visible light, and synthesizes the target product 2- (2-phenyl-2H-indazol-3-yl) acetate compound through a one-pot reaction without using a transition metal catalyst or a traditional volatile organic solvent. The preparation method is simple, convenient and safe to operate, mild in reaction condition, green and pollution-free due to visible light serving as a light source, environment-friendly due to the catalyst and the reaction medium, and relatively high in yield of the synthesized target product.

Detailed Description

The technical solution of the present invention is specifically described below by way of examples. It is to be noted that the following examples are only for further illustration of the present invention and should not be construed as limiting the scope of the present invention. Many non-essential modifications and adaptations of the present invention will occur to those skilled in the art in view of the foregoing description, and are intended to be within the scope of the present invention. In addition, the starting materials used are all commercially available, unless otherwise specified.

Example 1

Adding 2-phenyl-2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) into a 10mL reaction tube containing magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting a reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain a target product which is yellow oily. The yield of the desired product was 62% based on the molar amount of 2- (2-phenyl-2H-indazol-3-yl) acetate (100%).

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.75(d,J＝8.8Hz,1H),7.67(d,J＝8.5Hz,1H),7.62-7.60(m,2H),7.56-7.53(m,2H),7.52-7.49(m,1H),7.35-7.33(m,1H),7.14-7.12(m,1H),4.14(q,J＝7.1Hz,2H),4.04(s,2H),1.20(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.9,148.8,139.6,129.4,129.3,128.4,127.0,126.3,122.1,122.0,119.9,118.0,61.7,31.8,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₇N₂O₂ ⁺281.1285,Found:281.1287。

example 2

2- (p-tolyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) were sequentially added to a 10mL reaction tube containing magnetons, followed by addition of solvent water (2mL), reaction at room temperature under irradiation of a white LED lamp for 12 hours under air conditions, extraction of the reaction solution with ethyl acetate after the reaction was completed, combination of organic phases, drying with anhydrous sodium sulfate, removal of the organic phase, and separation by column chromatography to obtain the target product as a yellow oily substance. The yield of the desired product was 82% based on 100% molar amount of 2- (2- (p-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.66(d,J＝8.3Hz,1H),7.47(d,J＝8.3Hz,2H),7.35-7.32(m,3H),7.13-7.11(m,1H),4.14(q,J＝7.1Hz,2H),4.02(s,2H),2.45(s,3H),1.21(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,148.7,139.4,137.1,130.0,128.4,126.9,126.1,122.0,119.8,117.9,61.7,31.8,21.4,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₉N₂O₂ ⁺295.1441,Found:295.1444。

example 3

Adding 2- (4-methoxyphenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) in sequence into a 10mL reaction tube containing magnetons, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 63% based on 100% by mole of 2- (2- (p-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.66(d,J＝8.5Hz,1H),7.53-7.50(m,2H),7.35-7.32(m,1H),7.13-7.11(m,1H),7.04-7.02(m,2H),4.14(q,J＝7.1Hz,2H),4.01(s,2H),3.88(s,3H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,160.2,148.6,132.6,128.5,127.6,126.8,121.9,121.8,119.8,117.9,114.5,61.7,55.7,31.8,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₉N₂O₃ ⁺311.1390,Found:311.1391。

example 4

Adding 2- (4-fluorophenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) into a 10mL reaction tube containing magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting a reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain a target product which is yellow oily. The yield of the desired product was 70% based on 100% molar amount of 2- (2- (4-fluorophenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.73(d,J＝8.8Hz,1H),7.65(d,J＝8.5Hz,1H),7.62-7.59(m,2H),7.35-7.33(m,1H),7.25-7.21(m,2H),7.14-7.12(m,1H),4.14(q,J＝7.1Hz,2H),4.01(s,2H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,162.9(d,J＝249.0Hz),148.8,136.2(d,J＝3.0Hz),128.6,128.2(d,J＝9.0Hz),127.1,122.2,121.9,119.8,117.9,116.4(d,J＝22.5Hz),61.8,31.7,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-111.5。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆FN₂O₂ ⁺299.1190,Found:299.1189。

example 5

Adding 2- (4-chlorophenyl) -2H-indazole (0.2mmol), potassium ethylxanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) into a 10mL reaction tube containing magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 76% based on 100% molar amount of 2- (2- (4-chlorophenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.73(d,J＝8.8Hz,1H),7.66(d,J＝8.3Hz,1H),7.59-7.57(m,2H),7.53-7.51(m,2H),7.36-7.33(m,1H),7.15-7.12(m,1H),4.15(q,J＝7.1Hz,2H),4.02(s,2H),2.45(s,3H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,148.9,138.1,135.3,129.6,128.4,127.5,127.3,122.3,122.1,119.8,117.9,61.8,31.7,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆ClN₂O₂ ⁺315.0895,Found:315.0893。

example 6

Adding 2- (4-bromophenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) in sequence into a 10mL reaction tube containing magnetons, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting a reaction solution by using ethyl acetate after the reaction is finished, combining organic phases, drying by using anhydrous sodium sulfate, removing the organic phases, and carrying out column chromatography separation to obtain a target product which is yellow oily. The yield of the desired product was 71% based on the molar amount of 2- (2- (4-bromophenyl) -2H-indazol-3-yl) acetate (100%).

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.73(d,J＝8.8Hz,1H),7.69-7.65(m,3H),7.53-7.51(m,2H),7.36-7.33(m,1H),7.15-7.12(m,1H),4.15(q,J＝7.1Hz,2H),4.02(s,2H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,148.9,138.6,132.6,129.4,128.4,127.8,127.3,123.3,122.3,122.1,119.8,117.9,61.8,31.7,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆BrN₂O₂ ⁺359.0390,Found:359.0392。

example 7

2- (4- (trifluoromethyl) phenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, organic phases are combined and dried by anhydrous sodium sulfate, the organic phases are removed, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the desired product was 43% based on the molar amount of 2- (2- (4- (trifluoromethyl) phenyl) -2H-indazol-3-yl) acetate (100%).

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.82(dd,J₁＝12.6Hz,J₂＝8.9Hz,4H),7.75(d,J＝8.8Hz,1H),7.68(d,J＝8.5Hz,1H),7.38-7.35(m,1H),7.17-7.14(m,1H),4.16(q,J＝7.1Hz,2H),4.06(s,2H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,149.2,142.5,131.2(q,J＝33.0Hz),128.5,127.5,126.7(q,J＝4.5Hz),126.6,123.8(q,J＝271.5Hz),122.6,122.4,119.9,118.0,61.9,31.8,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-62.6。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₆F₃N₂O₂ ⁺349.1158,Found:349.1156。

example 8

2- (m-tolyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) were sequentially added to a 10mL reaction tube containing magnetons, followed by addition of solvent water (2mL), and the reaction was carried out at room temperature for 12 hours under irradiation of a white LED lamp under air conditions, after the reaction was completed, the reaction solution was extracted with ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, the organic phase was removed, and the target product was obtained as a yellow oily substance by column chromatography. The yield of the desired product was 71% based on 100% by mole of 2- (2- (m-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.75(d,J＝8.7Hz,1H),7.67(d,J＝8.5Hz,2H),7.43-7.38(m,3H),7.35-7.31(m,2H),7.14-7.12(m,1H),4.15(q,J＝7.1Hz,2H),4.04(s,2H),2.45(s,3H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,148.7,139.7,139.5,130.0,129.1,128.3,127.0,126.9,123.2,122.0,122.0,119.9,117.9,61.7,31.9,21.5,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₉N₂O₂ ⁺295.1441,Found:295.1442。

example 9

Adding 2- (3-fluorophenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) into a 10mL reaction tube containing magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting a reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain a target product which is yellow oily. The yield of the desired product was 50% based on 100% molar amount of 2- (2- (3-fluorophenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.67(d,J＝8.5Hz,1H),7.53-7.49(m,1H),7.45-7.41(m,2H),7.36-7.34(m,1H),7.23-7.20(m,1H),7.15-7.12(m,1H),4.16(q,J＝7.1Hz,2H),4.06(s,2H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,162.8(d,J＝247.5Hz),148.9,140.9(d,J＝10.5Hz),130.7(d,J＝9.0Hz),128.4,127.3,122.4,122.2,121.9(d,J＝3.0Hz),119.8,118.0,116.3(d,J＝21.0Hz),114.0(d,J＝25.5Hz),61.8,31.7,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-110.5。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆FN₂O₂ ⁺299.1190,Found:299.1190。

example 10

Adding 2- (3-chlorophenyl) -2H-indazole (0.2mmol), potassium ethylxanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equivalent) into a 10mL reaction tube containing magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 68% based on 100% molar amount of 2- (2- (3-chlorophenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.69-7.66(m,2H),7.55-7.54(m,1H),7.50-7.47(m,2H),7.37-7.34(m,1H),7.16-7.13(m,1H),4.16(q,J＝7.1Hz,2H),4.05(s,2H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,149.0,140.6,135.2,130.4,129.5,128.5,127.4,126.7,124.4,122.4,122.2,119.9,118.0,61.9,31.8,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆ClN₂O₂ ⁺315.0895,Found:315.0894。

example 11

Adding 2- (3-bromophenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) in sequence into a 10mL reaction tube containing magnetons, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting a reaction solution by using ethyl acetate after the reaction is finished, combining organic phases, drying by using anhydrous sodium sulfate, removing the organic phases, and carrying out column chromatography separation to obtain a target product which is yellow oily. The yield of the desired product was 60% based on the molar amount of 2- (2- (3-bromophenyl) -2H-indazol-3-yl) acetate (100%).

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.84(t,J＝1.9Hz,1H),7.74(d,J＝8.8Hz,1H),7.67-7.64(m,2H),7.60-7.58(m,1H),7.42(t,J＝8.0Hz,1H),7.36-7.34(m,1H),7.15-7.13(m,1H),4.16(q,J＝7.1Hz,2H),4.04(s,2H),1.24(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,148.9,140.7,132.4,130.6,129.5,128.5,127.4,124.8,122.9,122.4,122.1,119.9,117.9,61.9,31.8,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆BrN₂O₂ ⁺359.0390,Found:359.0389。

example 12

Adding 5-methoxy-2-phenyl-2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) into a 10mL reaction tube filled with magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phase, and separating by column chromatography to obtain the target product which is yellow oily. The yield of the desired product was 73% based on 100% molar amount of 2- (5-methoxy-2-phenyl-2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.65(d,J＝9.3Hz,1H),7.60-7.58(m,2H),7.55-7.52(m,2H),7.50-7.47(m,1H),7.05(dd,J₁＝9.2Hz,J₂＝2.3Hz,1H),6.84(d,J＝2.2Hz,1H),4.15(q,J＝7.1Hz,2H),3.99(s,2H),3.87(s,3H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.2,155.4,145.7,139.7,129.4,129.1,127.1,126.2,122.1,121.9,119.4,95.8,61.7,55.5,31.8,14.3。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₉N₂O₃ ⁺311.1390,Found:311.1386。

example 13

Adding 5-fluoro-2-phenyl-2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) into a 10mL reaction tube filled with magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phase, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 68% based on 100% molar amount of 2- (5-fluoro-2-phenyl-2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.73-7.71(m,1H),7.59-7.50(m,5H),7.25-7.23(m,1H),7.16-7.13(m,1H),4.15(q,J＝7.1Hz,2H),3.98(s,2H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,158.5(d,J＝240.0Hz),146.2,139.4,129.5,129.4,128.5(d,J＝9.0Hz),126.2,121.3(d,J＝12.0Hz),120.1(d,J＝9.0Hz),118.6(d,J＝28.5Hz),102.4(d,J＝24.0Hz),61.8,31.8,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-119.3。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆FN₂O₂ ⁺299.1190,Found:299.1191。

example 14

Adding 5-chloro-2-phenyl-2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) into a 10mL reaction tube filled with magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phase, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 73% based on 100% molar amount of 2- (5-chloro-2-phenyl-2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.69(d,J＝9.1Hz),7.66(d,J＝1.4Hz),7.60-7.51(m,5H),7.27(dd,J₁＝9.1Hz,J₂＝1.9Hz,1H),4.16(q,J＝7.1Hz,2H),3.99(s,2H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.7,147.1,139.3,129.5,129.5,128.4,128.2,127.7,126.2,122.4,119.6,118.7,61.9,31.7,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆N₂O₂ ⁺315.0895,Found:315.0896。

example 15

Adding 5-bromo-2-phenyl-2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) into a 10mL reaction tube filled with magnetons in sequence, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phase, and separating by column chromatography to obtain the target product which is yellow oily. The yield of the desired product was 58% based on 100% molar 2- (5-bromo-2-phenyl-2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.85(d,J＝1.1Hz,1H),7.63(d,J＝9.1Hz,1H),7.59-7.51(m,5H),7.39(dd,J₁＝9.1Hz,J₂＝1.7Hz,1H),4.16(q,J＝7.1Hz,2H),3.99(s,2H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.6,147.2,139.3,130.7,129.6,129.5,128.1,126.3,123.3,122.2,119.8,115.5,61.9,31.8,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₆BrN₂O₂ ⁺359.0390,Found:359.0387。

example 16

2- (3, 5-dimethylphenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, organic phases are combined and dried by anhydrous sodium sulfate, the organic phase is rotated off, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the desired product was 57% based on 100% molar 2- (2- (3, 5-dimethylphenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.67(d,J＝8.5Hz,1H),7.35-7.32(m,1H),7.21(s,2H),7.13-7.11(m,2H),4.15(q,J＝7.1Hz,2H),4.04(s,2H),2.40(s,6H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,148.6,139.4,139.3,130.9,128.3,126.8,123.9,122.0,121.9,119.9,117.9,61.6,31.9,21.4,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₉H₂₁N₂O₂ ⁺309.1598,Found:309.1594。

example 17

6-chloro-2- (p-tolyl) -2H-indazole (0.2mmol), potassium ethylxanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, and then, water (2mL) as a solvent is added thereto, and the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp, after the reaction is finished, the reaction solution is extracted with ethyl acetate, organic phases are combined and dried with anhydrous sodium sulfate, the organic phase is removed, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the desired product was 60% based on 100% by mole of 2- (6-chloro-2- (p-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.68(d,J＝9.1Hz,1H),7.65(d,J＝1.3Hz,1H),7.46-7.44(m,2H),7.34-7.33(m,2H),7.26(dd,J₁＝9.1Hz,J₂＝1.9Hz,1H),4.16(q,J＝7.1Hz,2H),3.97(s,2H),2.45(s,3H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.8,147.0,139.7,136.8,130.1,128.3,128.2,127.6,126.0,122.4,119.5,118.7,61.8,31.7,21.4,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₈ClN₂O₂ ⁺329.1051,Found:329.1051。

example 18

6-fluoro-2- (p-tolyl) -2H-indazole (0.2mmol), potassium ethylxanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, and then, water (2mL) as a solvent is added thereto, and the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp, after the reaction is finished, the reaction solution is extracted with ethyl acetate, organic phases are combined and dried with anhydrous sodium sulfate, the organic phase is removed, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the objective product was 39% based on 100% by mole of 2- (6-fluoro-2- (p-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.71(t,J＝4.6Hz,1H),7.46-7.45(m,2H),7.34-7.33(m,2H),7.23(dd,J₁＝9.0Hz,J₂＝2.2Hz,1H),7.15-7.11(m,1H),4.15(q,J＝7.1Hz,2H),3.96(s,2H),2.45(s,3H),1.22(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.9,158.5(d,J＝238.5Hz),146.1,139.6,136.9,130.0,128.5(d,J＝9.0Hz),126.0,121.2(d,J＝12.0Hz),120.1(d,J＝10.5Hz),118.5(d,J＝28.5Hz),102.4(d,J＝24.0Hz),61.8,31.8,21.4,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-119.5。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₈FN₂O₂ ⁺313.1347,Found:313.1336。

example 19

6-fluoro-2- (4-methoxyphenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) account for ton chloride (8% equivalent) are sequentially added into a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, after the organic phases are combined, anhydrous sodium sulfate is used for drying, the organic phase is rotated off, and the target product is obtained through column chromatography separation and is yellow oily matter. The yield of the desired product was 70% based on 100% molar amount of 2- (6-fluoro-2- (4-methoxyphenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.71(dd,J₁＝9.3Hz,J₂＝4.6Hz,1H),7.23(dd,J₁＝9.0Hz,J₂＝2.2Hz,1H),7.15-7.12(m,1H),7.05-7.02(m,2H),4.16(q,J＝7.1Hz,2H),3.95(s,2H)7.51-7.48(m,2H),,3.89(s,3H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.9,160.3,158.5(d,J＝240.0Hz),146.0,132.4,128.7(d,J＝9.0Hz),127.5,121.1(d,J＝10.5Hz),120.0(d,J＝9.0Hz),118.4(d,J＝30.0Hz),114.5,102.3(d,J＝24.0Hz),61.8,55.8,31.8,14.3。

¹⁹F NMR(564MHz,CDCl₃)δ-119.6。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₈FN₂O₃ ⁺329.1296,Found:329.1298。

example 20

2- (4-chlorophenyl) -6-methoxy-2H-indazole (0.2mmol), potassium ethylxanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, after the organic phases are combined, the drying is carried out by anhydrous sodium sulfate, the organic phase is rotated off, and the target product is obtained by column chromatography separation and is yellow oily matter. The yield of the target product was 60% based on 100% of the molar amount of 2- (2- (4-chlorophenyl) -6-methoxy-2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.63(d,J＝9.3Hz,1H),7.58-7.56(m,2H),7.52-7.49(m,2H),7.05(dd,J₁＝9.3Hz,J₂＝2.3Hz,1H),6.82(d,J＝2.2Hz,1H),4.16(q,J＝7.1Hz,2H),3.97(s,2H),3.87(s,3H),1.24(t,J＝7.2Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,155.5,145.8,138.3,135.0,129.6,127.4,127.1,122.5,122.1,119.4,95.7,61.8,55.5,31.8,14.3。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₈ClN₂O₃ ⁺345.1000,Found:345.1001。

example 21

Adding 2- (4-ethylphenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) in sequence into a 10mL reaction tube containing magnetons, then adding solvent water (2mL), reacting at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, extracting the reaction solution with ethyl acetate after the reaction is finished, combining organic phases, drying with anhydrous sodium sulfate, removing the organic phases, and separating by column chromatography to obtain the target product which is yellow oily matter. The yield of the desired product was 67% based on 100% molar 2- (2- (4-ethylphenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.75(d,J＝8.8Hz,1H),7.66(d,J＝8.5Hz,1H),7.51-7.50(m,2H),7.36-7.32(m,3H),7.14-7.11(m,1H),4.14(q,J＝7.1Hz,2H),4.03(s,2H),2.75(q,J＝7.6Hz,2H),1.30(t,J＝7.6Hz,3H),1.21(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ169.0,148.7,145.6,137.2,128.8,128.3,126.8,126.1,121.9,119.8,117.9,61.7,31.8,28.7,15.6,14.2。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₉H₂₁N₂O₂ ⁺309.1598,Found:309.1600。

example 22

2- (3-fluoro-4-methylphenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equivalents) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) account for ton chloride (8% equivalent) are sequentially added to a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, after the organic phases are combined, anhydrous sodium sulfate is used for drying, the organic phase is rotated off, and the target product is obtained through column chromatography separation and is yellow oily matter. The yield of the desired product was 63% based on 100% molar amount of 2- (2- (3-fluoro-4-methylphenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.66(d,J＝8.5Hz,1H),7.36-7.31(m,4H),7.14-7.12(m,1H),4.16(q,J＝7.1Hz,2H),4.04(s,2H),2.37(d,J＝1.6Hz,3H),1.23(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.9,161.0(d,J＝246.0Hz),148.8,138.4(d,J＝10.5Hz),131.9(d,J＝6.0Hz),128.4,127.2,126.4(d,J＝16.5Hz),122.2,122.0,121.6(d,J＝4.5Hz),119.8,117.9,113.5(d,J＝24.0Hz),61.8,31.8,14.6(d,J＝4.5Hz),14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-114.4。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₈FN₂O₂ ⁺313.1347,Found:313.1349。

example 23

2- (3, 5-difluorophenyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl bromoacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, then solvent water (2mL) is added, the reaction is carried out at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, organic phases are combined and dried by anhydrous sodium sulfate, the organic phases are removed, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the desired product was 71% based on 100% molar 2- (2- (3, 5-difluorophenyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.73(d,J＝8.8Hz,1H),7.66(d,J＝8.5Hz,1H),7.37-7.35(m,1H),7.31-7.28(m,2H),7.16-7.14(m,1H),7.00-6.96(m,1H),4.18(q,J＝7.1Hz,2H),4.08(s,2H),1.25(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.7,163.0(dd,J₁＝249.0Hz,J₂＝13.5Hz),149.1,141.6(t,J＝13.5Hz),128.5,127.7,119.9,118.0,110.0(dd,J₁＝21.0Hz,J₂＝6.0Hz),104.8(t,J＝25.5Hz),62.0,31.7,14.2。

¹⁹F NMR(564MHz,CDCl₃)δ-107.1。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₇H₁₅F₂N₂O₂ ⁺317.1096,Found:345.1097。

example 24

2- (p-tolyl) -2H-indazole (0.2mmol), potassium ethyl xanthate (0.6mmol), ethyl 2-chloroacetate (0.6mmol), lauroyl peroxide (2.5 equiv.) and 9- (2-carboxyphenyl) -3, 6-bis (diethylamino) xanthene chloride (8% equiv.) are sequentially added to a 10mL reaction tube containing magnetons, and then, water (2mL) as a solvent is added, and the reaction solution is reacted at room temperature for 12 hours under the irradiation of a white LED lamp under the air condition, after the reaction is finished, the reaction solution is extracted by ethyl acetate, organic phases are combined and dried by anhydrous sodium sulfate, the organic phase is rotated off, and the target product is obtained by column chromatography separation and is yellow oily. The yield of the desired product was 73% based on 100% by mole of 2- (2- (p-tolyl) -2H-indazol-3-yl) acetate.

The structural formula of the target product is as follows:

the yellow oil was analyzed by nuclear magnetic spectroscopy and mass spectrometry, and the data were as follows:

¹H NMR(600MHz,CDCl₃)δ7.74(d,J＝8.8Hz,1H),7.66(d,J＝8.3Hz,1H),7.47(d,J＝8.3Hz,2H),7.35-7.32(m,3H),7.13-7.11(m,1H),4.14(q,J＝7.1Hz,2H),4.02(s,2H),2.45(s,3H),1.21(t,J＝7.1Hz,3H)。

¹³C NMR(150MHz,CDCl₃)δ168.9,148.6,139.3,137.0,129.8,128.3,126.7,126.0,121.8,119.7,117.8,61.6,31.7,21.3,14.1。

HRMS(ESI-TOF)m/z:[M+H]⁺Calcd for C₁₈H₁₉N₂O₂ ⁺295.1441,Found:295.1444。

while there have been shown and described what are at present considered the fundamental principles of the invention, its essential features and advantages, the invention further resides in various changes and modifications which fall within the scope of the invention as claimed.