Synthetic method of 2, 3-diacyl quinoline compound
阅读说明：本技术 一种2,3-二酰基喹啉类化合物的合成方法 (Synthetic method of 2, 3-diacyl quinoline compound ) 是由 邹亮华 马成伟 邵泽宇 王成 任飞 刘双 宋盈盈 于 2020-12-18 设计创作，主要内容包括：本发明公开了一种2,3-二酰基喹啉类化合物的合成方法,将式Ι所示的苯并[c]异噁唑类化合物、式Ⅱ所示的铵盐类化合物溶于有机溶剂中,在铜催化剂和碱试剂的作用下进行反应,将所得反应液提纯即得到式Ⅲ所示的2,3-二酰基喹啉类化合物。本发明使用的原料价格低廉,催化剂廉价易得且用量少,操作简单,底物适用范围较广。(The invention discloses a synthesis method of a 2, 3-diacyl quinoline compound, which is prepared by reacting benzo [ c ] shown in formula I]Dissolving isoxazole compounds and ammonium salt compounds shown in formula II in an organic solvent, reacting under the action of a copper catalyst and an alkali reagent, and purifying the obtained reaction liquid to obtain the 2, 3-diacylquinoline compounds shown in formula III. The method has the advantages of low price of used raw materials, cheap and easily obtained catalyst, small using amount, simple operation and wider application range of the substrate.)
1. A method for synthesizing 2, 3-diacyl quinoline compounds comprises the steps of dissolving benzo [ c ] isoxazole compounds shown in formula I and ammonium salt compounds shown in formula II in an organic solvent, reacting under the action of a copper catalyst and an alkali reagent, purifying the obtained reaction liquid to obtain 2, 3-diacyl quinoline compounds shown in formula III,
wherein R is1Selected from H, halogen, C1-C4 alkyl, halogenated C1-C4 alkyl; r2Is selected from unsubstituted or substituted aryl and aromatic heterocyclic radical; the substituent substitution comprises any one of mono-substitution to tri-substitution, and the substituent is selected from halogen, C1-C4 alkyl, halogenated C1-C4 alkyl, C3-C6 cycloalkyl, halogenated C3-C6 cycloalkyl and aryl.
2. The method of claim 1, wherein the copper catalyst is selected from any one of: cuprous bromide, cupric chloride, cupric bromide, cuprous iodide.
3. The method of claim 1, wherein the base is selected from any one of: cesium carbonate, potassium phosphate, sodium carbonate, sodium tert-butoxide, cesium fluoride.
4. The method according to claim 1, wherein the organic solvent is selected from any one or more of: tetrahydrofuran, acetonitrile, dichloromethane, ethylene glycol dimethyl ether.
5. The method according to claim 1, wherein the substance amount ratio of benzo [ c ] isoxazole represented by formula I to the ammonium salt reagent represented by formula II is 1: 1.0-2.5.
6. The method according to claim 1, wherein the ratio of the benzo [ c ] isoxazole represented by formula I to the amount of the copper catalyst is 1: 0.05-0.2.
7. The method according to claim 1, wherein the amount ratio of the benzo [ c ] isoxazole represented by formula I to the inorganic base is 1: 1.0-3.5.
8. The method according to claim 1, wherein the amount of the organic solvent added is 2.5 to 10mL/mmol based on the amount of the benzo [ c ] isoxazole represented by formula I.
9. The method of claim 1, wherein the reaction is carried out in an oxygen atmosphere; the oxygen atmosphere is a gas atmosphere containing 20% or more of oxygen.
10. The method according to any one of claims 1 to 9, wherein the temperature of the reaction is 70 to 110 ℃; the reaction time is 6-12 h.
Technical Field
The invention belongs to the field of organic synthesis, and particularly relates to a synthetic method of a 2, 3-diacylquinoline compound.
Background
The 2, 3-diacyl quinoline compound is a core skeleton structure of bioactive substances, synthetic drugs and natural drugs, and has wide application in biological and pharmacological research. In addition, the 2, 3-diacylquinoline part has the functions of resisting bacteria, inflammation, malaria and the like, and the constructed diacylquinoline heterocyclic skeleton is also a key intermediate for synthesizing some important compounds.
The existing method for synthesizing the 2, 3-diacyl quinoline compound mainly has the following defects that a plurality of reactions are needed or raw materials are expensive, for example, o-aminobenzaldehyde is needed as a first-step initial raw material, the raw materials are expensive, and then the 2, 3-diacyl quinoline compound can be obtained by further oxidation, so that the number of steps is large, and the synthesis cost is high. At present, methods for synthesizing 2, 3-diacylquinolines are urgently needed. Under the background, the application researches a simple method for synthesizing the 2, 3-diacylquinoline compound, and the method has the advantages of cheap and easily-obtained raw materials and catalysts, small using amount of the catalysts, simple operation and wide application range of substrates.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a method for synthesizing a 2, 3-diacylquinoline compound, which has the advantages of low raw material price, small catalyst dosage, high catalytic efficiency and wide substrate application range.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for synthesizing 2, 3-diacyl quinoline compounds comprises the steps of reacting benzo [ c ] isoxazole compounds shown in a formula I and ammonium salt compounds shown in a formula II in an organic solvent under the action of a catalyst and an alkali reagent, purifying the obtained reaction liquid to obtain the 2, 3-diacyl quinoline compounds shown in a formula III,
wherein R is1Selected from H, halogen (F, Cl, Br), C1-C4 alkyl, halogenated C1-C4 alkyl; r2Is selected from unsubstituted or substituted aryl and aromatic heterocyclic radical; the substituent substitution includes one to three substitutionAny substituent is selected from halogen (F, Cl and Br), C1-C4 alkyl, halogenated C1-C4 alkyl, C3-C6 cycloalkyl, halogenated C3-C6 cycloalkyl and aryl.
In one embodiment of the present invention, the aryl group comprises a benzene ring or a naphthalene ring.
In one embodiment of the invention, the aromatic heterocycle comprises a C5-C6 aromatic ring containing one or more heteroatoms; wherein the heteroatom comprises N, O, S.
In one embodiment of the invention, R1Preferably H, F, Cl, Br or CF3。
In one embodiment of the invention, R2Preferably, it is
In one embodiment of the invention, during the reaction: under the action of a catalyst, a benzo [ c ] isoxazole compound shown in the formula I and an ammonium salt compound shown in the formula II are subjected to [4+1+1] cyclization to obtain the 2, 3-diacylquinoline compound.
In one embodiment of the present invention, the catalyst is a copper catalyst, and may be selected from any one or more of the following: cuprous bromide, cupric chloride, cupric bromide, cuprous iodide.
In one embodiment of the present invention, the alkali agent is an inorganic alkali selected from any one or more of the following: cesium carbonate, potassium phosphate, sodium carbonate, sodium tert-butoxide, cesium fluoride; cesium carbonate and cesium fluoride are preferred. Reference to an alkaline agent is to an agent that provides an alkaline environment.
In one embodiment of the present invention, the organic solvent is selected from any one or more of: tetrahydrofuran, acetonitrile, dichloromethane, ethylene glycol dimethyl ether.
In one embodiment of the invention, the reaction temperature is 70-110 ℃; the reaction time is 6-12 h.
In one embodiment of the present invention, the ratio of the amounts of the benzo [ c ] isoxazole compound represented by formula i and the ammonium salt compound represented by formula ii is 1:1.0 to 2.5.
In one embodiment of the present invention, the ratio of the benzo [ c ] isoxazole compound represented by formula i to the copper catalyst is 1:0.05 to 0.2.
In one embodiment of the present invention, the ratio of the benzo [ c ] isoxazole compound represented by formula i to the amount of the inorganic base is 1:1.0 to 3.5.
In one embodiment of the present invention, the amount of the organic solvent added is 2.5 to 10mL/mmol, based on the amount of the benzo [ c ] isoxazole compound represented by formula i.
In one embodiment of the invention, the reaction is carried out in an oxygen atmosphere. The oxygen atmosphere refers to a gas atmosphere containing more than 20% of oxygen, such as air, oxygen, etc. The higher the oxygen content, the higher the yield, preferably in pure oxygen.
In one embodiment of the invention, the method comprises: after the reaction is finished, purifying; the purification method comprises the following steps: adding column chromatography silica gel into the obtained reaction liquid, distilling under reduced pressure to remove the solvent, spin-drying until the silica gel adsorption product is powdered, loading on the silica gel column, eluting with mixed liquid of petroleum ether and ethyl acetate, collecting the pure product by TLC spot plate, and evaporating and concentrating to obtain the 2, 3-diacyl quinoline compound shown in the formula III.
The purification method can use column chromatography silica gel of 200-300 meshes; the volume ratio of the petroleum ether to the ethyl acetate may be 20:1 or 15:1, and the volume ratio may be adjusted as needed.
Compared with the prior art, the invention has the following beneficial effects:
the reported methods for synthesizing the 2, 3-diacyl quinoline compounds have obvious disadvantages, wherein some methods need multiple reactions or expensive raw materials, so that chemical raw materials are greatly consumed, and the industrial cost for synthesizing the 2, 3-diacyl quinoline compounds is increased. Aiming at the situations, the invention develops a method for synthesizing the 2, 3-diacylquinoline compound by using cheap raw materials, cheap and easily-obtained catalyst and small using amount, wherein the copper catalyst only needs 0.1 equivalent, the operation is simple, and the application range of the substrate is wide, thereby reducing the industrial cost.
Detailed Description
The technical solution of the present invention will be further described in detail with reference to the following specific examples.
The benzisoxazole starting material used in the present invention can be prepared on its own according to the existing literature, for example, the literature Wang, f.; xu, p.; wang, s.y.; ji, S.J.org.Lett.2018,20, 2204-. The invention provides a synthesis method which comprises the following steps:
adding o-nitrobenzaldehyde (3mmol) and anhydrous stannous chloride (9mmol) into a reaction flask with magnetic stirring, preparing a solution of methanol and ethyl acetate (1:1,20ml), adding into the reaction flask, and stirring at room temperature for 24 hours. At the end of the reaction, the reaction was quenched with saturated sodium bicarbonate solution (20ml), extracted with ethyl acetate (3 × 10ml), the organic phase was washed with water (20ml), saturated brine (20ml), the organic phase was dried over anhydrous sodium sulfate, left to stand, filtered and concentrated by evaporation, purified by column chromatography petroleum ether: ethyl acetate was purified 30:1 to give the product.
The synthetic route is as follows:
the substituted arylformylammonium salts used according to the invention can be prepared themselves according to known methods, for example the documents Lina Liu, Zhen bo Yuan, Rui Pan, a Yu ye Zeng, Ai jun Lin, He quan Yao and Yue Huang org. chem. Front, 2018,5, 623-. The invention provides a synthesis method which comprises the following steps:
a250 mL round-bottom flask was charged with 2-bromoacetophenone (20mmol) and tetrahydrofuran (60mL), dissolved, and then, trimethylamine (20mmol) was added dropwise, followed by stirring at room temperature overnight. And (4) carrying out suction filtration on the reaction solution, washing twice with EA, and vacuumizing and drying the obtained solid to finally obtain the raw material.
The synthetic route is as follows:
example 1
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: benzisoxazole (0.2mmol,23.8mg), ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh and 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting with a mixed solution of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 58%. This material was a tan solid with a melting point of 120.2-122.5 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.39(s,1H),8.22(d,J＝8.5Hz,1H),8.12–8.04(m, 2H),7.97–7.82(m,4H),7.70(ddd,J＝8.1,6.9,1.2Hz,1H),7.58(dd,J＝7.8,6.0Hz,2H),7.45(q, J＝7.8Hz,4H)；13C NMR(101MHz,CDCl3)δ195.0,193.6,156.3,146.8,138.0,136.7,135.7, 133.4(d,J＝5.8Hz),132.9,131.8,130.9,130.1,130.0,128.9,128.6,128.4,128.3,126.6.
example 2
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 5-Fluorobenzisoxazole (0.2mmol,27.4mg), ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed liquid of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 39%. The material is a tan solid with a melting point of 121.1-124.6 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.33(d,J＝0.7Hz,1H),8.23(dd,J＝9.2,5.2Hz, 1H),8.10–8.04(m,2H),7.92–7.81(m,2H),7.69–7.51(m,4H),7.50–7.40(m,4H)；13C NMR (101MHz,CDCl3)δ194.8,193.2,163.1,160.6,155.5,143.8,137.0,136.9,136.6,135.5,133.9, 133.6,133.5,132.8,132.7,130.9,130.0,128.6,128.3,127.7,127.6,122.1,121.9,111.6,111.4.
example 3
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 5-chlorobenzoisoxazole (0.2mmol,30.7mg), an ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed liquid of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 54%. The material is a yellow solid with a melting point of 143.8-146.2 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.22(s,1H),8.08(d,J＝9.0Hz,1H),7.99(d,J＝ 7.4Hz,2H),7.87–7.69(m,4H),7.52(q,J＝7.0Hz,2H),7.39(q,J＝7.7Hz,4H)；13C NMR(101 MHz,CDCl3)δ193.6,192.2,155.3,144.0,135.7,135.4,134.4,133.9,132.9,132.5,131.6,130.6, 129.9,128.9,127.6,127.3,126.2,126.1–125.7(m).
example 4
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 5-bromobenzisoxazole (0.2mmol,39.6mg), ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed solution of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 44%. This material was a tan solid with a melting point of 140.3-142.7 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.29(s,1H),8.12–8.04(m,4H),7.93(dd,J＝9.0, 2.2Hz,1H),7.88–7.80(m,2H),7.66–7.54(m,2H),7.46(q,J＝7.7Hz,4H)；13C NMR(101 MHz,CDCl3)δ194.6,193.2,156.5,145.3,136.6,136.5,135.4,135.2,133.9,133.6,131.7,130.9, 130.4,130.0,128.7,128.3,127.7,123.2.
example 5
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 6-trifluoromethylbenzisoxazole (0.2mmol,37.4mg), ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting with mixed solution of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing the target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 48%. This material was a yellow solid with a melting point of 150.4-152.8 ℃.
Characterization data:1H NMR(500MHz,CDCl3)δ8.61–8.56(m,1H),8.47(s,1H),8.16–8.04(m, 3H),7.90(ddd,J＝9.6,8.5,1.6Hz,3H),7.70–7.59(m,2H),7.51(dt,J＝13.7,7.8Hz,4H)；13C NMR(126MHz,CDCl3)δ194.5,193.1,157.5,145.7,137.4,136.9,136.4,135.3,135.0,133.8, 133.7,133.5,133.2,132.9,130.9,130.0,129.6,128.7,128.4,128.1,127.9(d,J＝4.3Hz),127.3, 126.8,125.0–124.2(m),122.5,120.3.
example 6
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 6-fluorobenzoisoxazole (0.2mmol,27.4mg), an ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed liquid of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 52%. The material is a yellow solid with a melting point of 150.4-152.1 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.40(s,1H),8.07–8.02(m,2H),7.93(dd,J＝9.0, 5.9Hz,1H),7.87–7.79(m,3H),7.64–7.53(m,2H),7.52–7.41(m,5H)；13C NMR(101MHz, CDCl3)δ194.7,193.5,165.7,163.2,157.6,148.1,147.9,138.0,136.6,135.5,133.6,133.5,132.3, 132.2,130.8,130.7,130.6,130.0,128.6,128.4,123.6,119.6,119.4,114.0,113.8.
example 7
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 6-chlorobenzoisoxazole (0.2mmol,30.7mg), an ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed liquid of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 50%. The material was a yellow solid with a melting point of 192.3-194.8 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.29(s,1H),8.14(d,J＝2.1Hz,1H),7.99–7.93(m, 2H),7.77(dt,J＝7.0,4.0Hz,3H),7.61–7.47(m,3H),7.38(q,J＝8.0Hz,4H)；13C NMR(101 MHz,CDCl3)δ194.6,193.3,157.4,147.1,137.9,137.7,136.5,135.4,133.6,133.5,133.1,130.9, 130.0,129.5,129.1,128.6,128.4,124.9.
example 8
The structural formula for preparing the 2, 3-diacyl quinoline compound in this example is as follows:
the preparation method comprises the following steps: 6-bromobenzisoxazole (0.2mmol,39.6mg), ammonium salt (0.24mmol,61.7mg), cuprous bromide (0.02mmol,2.9mg) and cesium carbonate (0.5mmol,162.9mg) were added to a 25ml Schlenk tube, and the reaction tube was replaced with oxygen three times under reduced pressure. Dichloromethane (2ml) was added and stirred at 110 ℃ for 6 hours. After the reaction is finished, adding 200-mesh 300-mesh column chromatography silica gel, distilling under reduced pressure to remove the solvent, carrying out silica gel column chromatography separation on the crude product, eluting by using mixed liquid of petroleum ether and ethyl acetate (petroleum ether: ethyl acetate: 20:1), carrying out TLC (thin layer chromatography) elution tracking detection, collecting eluent containing a target product, combining the target product eluent, and carrying out evaporation concentration to obtain the 2, 3-diacylquinoline compound with the yield of 62%. This material was a yellow solid with a melting point of 192.1-194.6 ℃.
Characterization data:1H NMR(400MHz,CDCl3)δ8.33(s,1H),8.28(s,1H),8.04–7.92(m,2H),7.78 –7.74(m,2H),7.71(s,2H),7.52(q,J＝7.7Hz,2H),7.38(q,J＝8.0Hz,4H)；13C NMR(101MHz, CDCl3)δ194.6,193.2,157.3,147.2,137.8,136.5,135.4,133.6,133.6,133.3,132.5,132.4,130.9, 130.0,129.5,128.7,128.3,126.2,125.2.
example 9 investigation of the influence of base selection on the reaction
Referring to example 1, the corresponding target product was prepared without adding cesium carbonate or replacing the alkali agent from cesium carbonate with potassium carbonate, potassium phosphate, sodium carbonate, sodium tert-butoxide, cesium fluoride, or the like. The results are shown in Table 1.
TABLE 1 results of the reaction in different alkaline environments
Alkali reagent
Reaction yield (%)
Cesium carbonate (example 1)
58
Potassium carbonate
5
Potassium phosphate
15
Sodium carbonate
13
Sodium tert-butoxide
n.d
Cesium fluoride
40
Example 10 investigation of the Effect of copper catalyst selection on the reaction
Referring to example 1, the copper catalyst was replaced with cuprous bromide, cupric bromide, cuprous iodide.
And other parts are unchanged, and the corresponding target product is prepared. The results are shown in Table 2.
TABLE 2 results of different copper catalyst reactions
Copper catalyst
Reaction yield (%)
Cuprous bromide (example 1)
58
Copper chloride
50
Copper bromide
48
Cuprous iodide
40
Example 11 investigation of the Effect of solvent systems on the reaction
Referring to example 1, the solvent was replaced by tetrahydrofuran, acetonitrile, ethylene glycol dimethyl ether, dimethylformamide from DCM.
And other parts are unchanged, and the corresponding target product is prepared. The results are shown in Table 3.
TABLE 3 results of different copper catalyst reactions
Solvent(s)
Reaction yield (%)
DCM (example 1)
58
Tetrahydrofuran (THF)
23
Acetonitrile
32
Ethylene glycol dimethyl ether
43
Dimethyl formamide
n.d