CN116589472A - A kind of benzofuro[3,2-d]pyrimidin-2-amine compound and its preparation method and application - Google Patents

Abstract

The application belongs to the field of chemical pesticides, relates to synthesis of benzofuran [3,2-d ] pyrimidine-2-amine compounds, and in particular relates to a benzofuran [3,2-d ] pyrimidine-2-amine compound, and a preparation method and application thereof. The application prepares the benzofuran [3,2-d ] pyrimidine-2-amine compound by mixing and stirring a 2-styryl-3-sulfonamide compound, alkali and hydrofluoric acid salt in a solvent, and then adding an N-aryl-N-cyano-p-toluenesulfonamide compound for synthesis reaction. Compared with the traditional synthesis method, the method has the advantages of easy preparation of raw materials, highest 99% yield, mild reaction conditions, simple operation and the like, and the synthesized benzofuran [3,2-d ] pyrimidine-2-amine compound has good insecticidal activity through insecticidal activity screening, so that the method has important significance for the synthesis and application research of the compound.

Description

A kind of benzofuro[3,2-d]pyrimidin-2-amine compound and its preparation method and application

technical field

The invention belongs to the field of chemical pesticides, and relates to the synthesis of benzofuro[3,2-d]pyrimidin-2-amine compounds, in particular to a benzofuro[3,2-d]pyrimidin-2-amine Compounds and their preparation methods and applications.

Background technique

The ring-joined skeleton containing both oxygen and nitrogen atoms is a very important class of heterocyclic compounds, which widely exist in natural products and molecules with biological activity (J.Med.Chem.2006,49,4568; Eur. J. Med. Chem. 2015, 97, 388.). Wherein benzofuro[3,2-d]pyrimidin-2-amine compounds have also shown excellent biological activity, such as histamine H ₄ receptor antagonist activity (Bioorg.Med.Chem.Lett.2011,21 ,6577.) and anti-tumor activity (Synth.Commun.2022,52,994.). The synthesis of this kind of skeleton by using the structure of carbon-nitrogen bond has potential application value in drug synthesis and organic synthesis methodology (Chem. Commun. 2018, 54, 5154.)

N-aryl-N-cyano p-toluenesulfonamide compounds are widely used in the synthesis of nitrogen-containing heterocyclic compounds through cyanamide anion intermediates, and can be used to synthesize a series of important nitrogen-containing heterocyclic compounds (Org.Lett. 2016, 18, 1100; J. Org. Chem, 2021, 86, 3546; Org. Chem Front. 2022, 9, 1574.). Benzofuro[3,2-d]pyrimidin-2-amine compounds have potential biological activity, and their development is of great significance. In recent years, there are not many reports on the synthesis methods of benzofuro[3,2-d]pyrimidin-2-amine compounds, and the existing synthesis methods have complicated substrate preparation (Org.Lett.2012,14,2398. ), long routes (Synth.Commun.2022,52,994.), harsh reaction conditions (Bioorg.Med.Chem.Lett.2010,20,2516.) and other shortcomings, the synthesis efficiency is low. Therefore, it is of great practical value to develop a simple, efficient, and green-friendly method for the efficient synthesis of benzofuro[3,2-d]pyrimidin-2-amines.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention proposes a benzofuro[3,2-d]pyrimidin-2-amine compound and its preparation method and application, realizing N-aryl-N-cyano-p-toluenesulfonate for the first time Cycloaddition reaction of amide compound with 2-styryl-3-sulfonamidobenzofuran to construct benzofuro[3,2-d]pyrimidin-2-amine skeleton. This method is of great significance for the study of the cycloaddition reaction of N-aryl-N-cyano p-toluenesulfonyl compounds via carbodiimide anion intermediates.

Technical scheme of the present invention is realized like this:

The application provides a structural formula of benzofuro[3,2-d]pyrimidin-2-amine compound: Wherein ^R is selected from any of phenyl, substituted phenyl, and ^R is selected from any of phenyl, substituted phenyl, and naphthyl.

Preferably, this application claims the following types of benzofuro[3,2-d]pyrimidin-2-amine compounds:

In the formula, X is a halogen, where X is halogen, />

The application also provides a synthetic method of benzofuro[3,2-d]pyrimidin-2-amine compound, the steps are as follows: N-aryl-N cyano-p-toluenesulfonamide compound, alkali and hydrofluoric Dissolve the acid salt in the solvent, mix and stir for 10-30 minutes, then add 2-styryl-3-sulfonamidobenzofuran compound to continue the synthesis reaction to obtain benzofuro[3,2-d]pyrimidine -2-amine compound;

The synthetic route is:

The structural formula of the above-mentioned 2-styryl-3-sulfonamidobenzofuran compound is: In the formula, R ¹ is selected from any one of phenyl, substituted phenyl; R ² is selected from any one of benzenesulfonyl, p-toluenesulfonyl and p-nitrobenzenesulfonyl; the N-aryl The structural formula of -N-cyano p-toluenesulfonamide compound is: /> In the formula, ^R is selected from any one of phenyl, substituted phenyl and naphthyl.

The molar ratio of the above-mentioned 2-styryl-3-sulfonamidobenzofuran compound, N-aryl-N-cyano p-toluenesulfonyl compound, alkali and hydrofluoric acid salt is: 1: (1～ 5): (2~5): (2~5).

The above-mentioned base is selected from any one of potassium carbonate, cesium carbonate, sodium carbonate and triethylamine.

The above-mentioned hydrofluoride is selected from any one of triethylamine hydrofluoride, pyridine hydrofluoride and tetra-n-butylammonium difluoride.

The above alkali and hydrofluoride are cesium carbonate and triethylamine hydrofluoride.

The above synthesis process is to first dissolve N-aryl-N cyano-p-toluenesulfonamide compound, alkali and hydrofluoride in a solvent, mix and stir for 10-30 minutes, then add 2-styryl-3-sulfonamide The synthesis reaction of benzofuran compound is continued.

The temperature of the above synthesis reaction is -10-50°C.

The above synthesis reaction system also includes a solvent.

The above-mentioned solvent is selected from any one of acetonitrile, dichloromethane, 1,2-dichloroethane, toluene, 1,4-dioxane, and ethyl acetate.

The amount of the above-mentioned solvent added is based on the reaction system, and the amount used is 0.02-2 mol/L.

The present invention has the following beneficial effects:

1. The present invention uses N-aryl-N-cyano p-toluenesulfonamide compound and 2-styryl-3-sulfonamidobenzofuran compound as raw materials for the first time. Under the action of alkali and hydrofluoric acid salt, The reaction generates benzofuro[3,2-d]pyrimidin-2-amine compounds, and at the same time, there are more options for substrate reactions; this application synthesizes benzofuro[3,2-d]pyrimidin-2-amine The mechanism of the compound is: the [4+2] cycloaddition reaction mechanism of 2-styryl-3-sulfonamidobenzofuran compound and N-aryl-N-cyano p-toluenesulfonamide compound is as follows: N- Aryl-N-cyano p-toluenesulfonamide removes the p-toluenesulfonyl group under the action of fluoride ion to obtain a carbodiimide anion intermediate, which is connected in series with 2-styryl-3-sulfonamidobenzofuran compound The process of Michael addition/ring closure/aromatization yields benzofuro[3,2-d]pyrimidin-2-amine compounds.

2. Compared with the traditional synthetic method, the method of the present invention has many advantages such as easy preparation of raw materials, up to 99% yield, mild reaction conditions, and simple operation. After screening for insecticidal activity, it is found that the synthesized benzofuran [3,2- d] Pyrimidin-2-amine compounds have good insecticidal activity, and the research on the synthesis and application of such compounds will be of great significance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is the ¹ H NMR chart of Example 1.

FIG. 2 is the ¹³ C NMR chart of Example 1.

FIG. 3 is the ¹ H NMR chart of Example 2.

FIG. 4 is the ¹³ C NMR chart of Example 2.

FIG. 5 is the ¹ H NMR chart of Example 3.

FIG. 6 is the ¹³ C NMR chart of Example 3.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

The synthetic method of N,4-diphenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 82mg of N-phenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, then add 2-benzene Vinyl-3-p-methanesulfonamidobenzofuran 75 mg was stirred at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, ethyl acetate was added to extract three times, the organic phases were combined, and column chromatography separated to obtain pure N,4-diphenylbenzofuro[3,2-d]pyrimidin-2-amine. Product 67mg, productive rate 99%, structural formula is: ¹ HNMR (600MHz, CDCl ₃ ) of pure N,4-diphenylbenzofuro[3,2-d]pyrimidin-2-amine δ8.57(d, J=8.4Hz, 2H), 8.18( d,J=7.8Hz,1H),7.82(d,J=7.8Hz,2H),7.65-7.64(m,2H),7.60(t,J=7.2Hz,2H),7.55(t,J=7.2 Hz, 1H), 7.44-7.36 (m, 4H), 7.05 (t, J=7.2Hz, 1H) ppm; ¹³ C NMR (151MHz, CDCl ₃ ) δ158.7, 156.8, 152.7, 148.1, 141.2, 140.6, 134.6, 131.5,131.2,129.3,129.1,128.9,123.8,122.5,122.1,122.0,118.7,112.9ppm; HRMS(ESI)m/z:[M+H] ⁺ Calcd for C ₂₂ H ₁₆ N ₃ O 338.1288,found: 338.1297.

Its ¹ H NMR chart and ¹³ C NMR chart are shown in Fig. 1 and Fig. 2 .

Example 2

The synthetic method of N-p-methoxyphenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 91mg of N-p-methoxyphenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 75 mg of 2-styryl-3-p-methylsulfonamidobenzofuran was stirred at 50°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, ethyl acetate was added to extract three times, and the organic phases were combined and separated by column chromatography to obtain N-p-methoxyphenyl-4-phenylbenzofuran[3,2-d] and Pyrimidin-2-amine pure product 64mg, yield 90%, structural formula is:

¹ H NMR (600MHz, DMSO-d ₆ ) of pure N-p-methoxyphenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine δ9.60(s,1H ), 8.48(d, J=7.2Hz, 2H), 8.11(d, J=7.8Hz, 1H), 7.84-7.81(m, 3H), 7.74(t, J=7.8Hz, 1H), 7.66(t ,J=7.8Hz,2H),7.61(t,J=7.2Hz,1H),7.50(t,J=7.8Hz,1H),6.94(d,J=9.0Hz,2H),3.75(s,3H ) ppm; ¹³ C NMR (151MHz, DMSO-d ₆ ) δ157.8, 157.1, 154.0, 151.9, 146.9, 139.8, 134.3, 134.1, 131.8, 131.1, 128.9, 128.6, 124.0, 121.8, 121.2, 120.1, 113.8,113.0, 55.2ppm; HRMS (ESI) m/z: [M+H] ⁺ Calcd for C ₂₃ H ₁₈ N ₃ O ₂ 368.1394, found 368.1398.

Its ¹ H NMR chart and ¹³ C NMR chart are shown in Fig. 3 and Fig. 4 .

Example 3

The synthetic method of N-p-methylphenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 86mg of N-p-methylphenyl-N-cyano-p-toluenesulfonyl, 80mg of potassium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 2 - 75 mg of styryl-3-p-methylsulfonamidobenzofuran, and continued stirring at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, ethyl acetate was added to extract three times, the organic phases were combined, and separated by column chromatography to obtain N-p-methylphenyl-4-phenylbenzofuro[3,2-d]pyrimidine -2-amine pure product 70mg, productive rate 99%, structural formula is:

¹ H NMR (600MHz, CDCl ₃ ) of pure N-p-methylphenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine δ8.55(d, J=7.8Hz ,2H),8.15(d,J=7.8Hz,1H),7.68(d,J=7.8Hz,2H),7.64-7.62(m,2H),7.58(t,J=7.8Hz,2H),7.54 (t, J=7.2Hz, 1H), 7.41-7.39(m, 1H), 7.29(s, 1H), 7.19(d, J=8.4Hz, 2H), 2.35(s, 3H) ppm; ¹³ C NMR (151MHz, CDCl ₃ ) δ158.6, 157.0, 152.6, 148.0, 141.1, 138.0, 134.7, 131.5, 131.4, 131.1, 129.5, 129.2, 128.9, 123.7, 122.4, 122.0, 118.9, 112.8, 2 0.9ppm; HRMS(ESI)m /z:[M+H] ⁺ Calcd for C ₂₃ H ₁₈ N ₃ O 352.1444, found 352.1463.

Its ¹ H NMR chart and ¹³ C NMR chart are shown in Fig. 5 and Fig. 6 .

Example 4

The synthetic method of N-p-fluorophenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 87mg of N-p-fluorophenyl-N-cyano-p-toluenesulfonyl, 64mg of sodium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 2- 75 mg of styryl-3-p-methylsulfonamidobenzofuran was stirred at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, and ethyl acetate was added to extract three times. The organic phases were combined and separated by column chromatography to obtain N-p-fluorophenyl-4-phenylbenzofuro[3,2-d]pyrimidine- 2-amine pure product 70mg, yield 99%, structural formula is:

¹ H NMR (400MHz, CDCl ₃ ) of pure N-p-fluorophenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine δ8.54-8.52(m,2H), 8.15(d,J=8.0Hz,1H),7.74-7.71(m,2H),7.67-7.53(m,5H),7.44-7.40(m,1H),7.34(s,1H),7.10-7.05( m, 2H) ppm; ¹³ C NMR (151MHz, CDCl ₃ ) δ158.7, 158.3 (d, J=240.1Hz), 156.8, 152.6, 148.1, 141.2, 136.6 (d, J=3.0Hz), 134.5, 131.5, 131.2 , 129.2, 128.9, 123.7, 122.4, 121.9, 120.3 (d, J=7.6Hz), 115.6 (d, J=22.7Hz), 112.9ppm; ¹⁹ F NMR (565MHz, CDCl ₃ ) δ-121.6ppm; HRMS ( ESI) m/z: [M+H] ⁺ Calcd for C ₂₂ H ₁₅ FN ₃ O 356.1194, found 356.1183.

Example 5

The synthetic method of N-phenyl-4-p-chlorophenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 82mg of N-phenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 28mg of pyridine hydrofluoride, 2mL of toluene, stir at 25°C for 10 minutes, add 2-p-chlorostyrene 82 mg of 3-p-methylsulfonamidobenzofuran was added, and stirring was continued at -10°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, and ethyl acetate was added to extract three times. The organic phases were combined and separated by column chromatography to obtain N-phenyl-4-p-chlorophenylbenzofuro[3,2-d]pyrimidine- 36 mg of pure 2-amine, yield 49%, structural formula:

¹ H NMR (400MHz, DMSO-d ₆ ) of pure N-phenyl-4-p-chlorophenylbenzofuro[3,2-d]pyrimidin-2-amine δ9.83(s,1H), 8.47(d, J=8.4Hz, 2H), 8.12(d, J=7.6Hz, 1H), 7.93(d, J=8.0Hz, 2H), 7.84-7.70(m, 4H), 7.51(t,J =7.2Hz, 1H), 7.36(t, J=7.6Hz, 2H), 6.99(t, J=7.6Hz, 1H) ppm; ¹³ C NMR (151MHz, DMSO-d ₆ ) δ157.9, 156.7, 152.1, 145.5 ,141.0,139.8,136.0,132.8,132.0,130.2,129.7,129.1,128.5,124.1,121.9,121.1,118.4,113.0ppm; HRMS(ESI)m/z:[M+H] ⁺ Calcd for C ₂₂ H ₁₅ ClN ₃ O 372.0898, found 372.0910.

Example 6

The synthetic method of N-phenyl-4-p-bromophenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 82mg of N-phenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 32mg of triethylamine hydrofluoric acid, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 2-p-bromobenzene Vinyl-3-p-methanesulfonamidobenzofuran 91 mg was stirred at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, and ethyl acetate was added to extract three times. The organic phases were combined and separated by column chromatography to obtain N-phenyl-4-p-bromophenylbenzofuro[3,2-d]pyrimidine- 2-amine pure product 63mg, yield 76%, structural formula is:

¹ H NMR (600MHz, CDCl ₃ ) of pure N-phenyl-4-p-bromophenylbenzofuro[3,2-d]pyrimidin-2-amine δ8.42(d, J=9.0Hz, 2H), 8.16(d, J=7.8Hz, 1H), 7.77(d, J=7.8Hz, 2H), 7.70(d, J=8.4Hz, 2H), 7.66-7.61(m, 2H), 7.44- 7.37 (m, 3H), 7.31 (s, 1H), 7.06 (t, J=7.8Hz, 1H) ppm; ¹³ C NMR (151MHz, CDCl ₃ ) δ158.7, 156.8, 153.0, 146.7, 141.0, 140.4, 133.5, 132.2, 131.7, 130.7, 129.1, 125.9, 123.9, 122.5, 122.2, 121.9, 118.7, 112.9ppm; HRMS (ESI) m/z: [M+H] ⁺ Calcdfor C ₂₂ H ₁₅ Br ⁷⁹ N ₃ O416.0393, found 416.0388.

Example 7

The synthetic method of N-phenyl-4-m-chlorophenylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 82mg of N-phenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 2-m-chloro 82 mg of styryl-3-p-methylsulfonamidobenzofuran was stirred at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, and ethyl acetate was added to extract three times. The organic phases were combined and separated by column chromatography to obtain N-phenyl-4-m-chlorophenylbenzofuro[3,2-d]pyrimidine- 2-amine pure product 71mg, yield 96%, structural formula is:

¹ H NMR (600MHz, DMSO-d ₆ ) of pure N-phenyl-4-m-chlorophenylbenzofuro[3,2-d]pyrimidin-2-amine δ9.81(s,1H), 8.43-8.40(m, 2H), 8.10(d, J=7.8Hz, 1H), 7.92(d, J=7.8Hz, 2H), 7.82(d, J=7.8Hz, 1H), 7.76-7.73(m ,1H),7.68-7.64(m,2H),7.50(t,J=7.8Hz,1H),7.36(t,J=7.8Hz,2H),7.00(t,J=7.2Hz,1H)ppm; ¹³ C NMR (151MHz, DMSO-d ₆ ) δ157.9, 156.6, 152.2, 144.9, 140.9, 139.8, 135.9, 133.7, 132.0, 130.81, 130.76, 128.4, 127.8, 127.2, 124.0, 121.8, 121 .1, 120.9, 118.4, 113.0 ppm; HRMS (ESI) m/z: [M+H] ⁺ Calcd for C ₂₂ H ₁₅ ClN ₃ O 372.0898, found 372.0892.

Example 8

The synthetic method of N-phenyl-4-furylbenzofuro[3,2-d]pyrimidin-2-amine, the steps are as follows:

Take a 25mL reaction bottle, add 82mg of N-phenyl-N-cyano-p-toluenesulfonyl, 65mg of cesium carbonate, 32mg of triethylamine hydrofluoride, 2mL of acetonitrile, stir at 25°C for 10 minutes, add 2-furan vinyl 73 mg of methyl-3-p-methylsulfonamidobenzofuran was stirred at 25°C for 24 hours. After the reaction was completed, 10 mL of water was added to quench the reaction, and ethyl acetate was added to extract three times. The organic phases were combined and separated by column chromatography to obtain N-phenyl-4-furylbenzofuro[3,2-d]pyrimidine-2- Pure amine 49mg, yield 75%, structural formula is:

¹ H NMR (400MHz, CDCl ₃ ) of pure N-phenyl-4-furylbenzofuro[3,2-d]pyrimidin-2-amine δ8.17 (d, J=8.0Hz, 1H) ,7.82(d,J=8.0Hz,2H),7.77(d,J=0.8Hz 1H),7.64-7.63(m,3H),7.44-7.36(m,4H),7.05(t,J=7.6Hz ,1H),6.70-6.69(m,1H)ppm; ¹³ C NMR(100MHz,CDCl ₃ )δ158.7,156.7,151.9,148.4,145.8,140.5,139.6,138.5,131.4,129.1,123.8,122.4,122.1,1 22.0 , 118.5, 116.8, 112.9, 112.7ppm; IR (KBr): v 3449, 2832, 1593, 1538, 1497, 1440, 1356, 1204, 1083, 744cm ^-1 ; HRMS (ESI) m/z: [M+H ] ⁺ Calcd for C ₂₀ H ₁₄ N ₃ O ₂ 328.1081,found 328.1095.

Example of implementation effect

In order to verify the biological activity of the benzofuro[3,2-d]pyrimidin-2-amine compound synthesized according to the synthetic method of this example, the Airbrush spray method was used to screen the synthetic compound against Plutella xylostella at different concentrations. Insect activity. Experiments show that most of the compounds have good insecticidal activity against third instar larvae of diamondback moth at 5 mg L ^-1 , and still have certain insecticidal activity against third instar larvae of diamondback moth at 2.5 mg L ^-1 , wherein Example 4 The prepared N-p-fluorophenyl-4-phenylbenzofuro[3,2-d]pyrimidin-2-amine has the best insecticidal effect on the third instar larvae of Plutella xylostella, as shown in Table 1;

Table 1 Mortality value of benzofuro[3,2-d]pyrimidin-2-amine to Plutella xylostella

It can be seen from Table 1 that the benzofuro[3,2-d]pyrimidin-2-amine compound synthesized by this method has a lethality rate of more than 90% to the third instar larvae of Plutella xylostella at a concentration of 5 mg·L ^-1 . Wherein compound 3, compound 4, compound 5 reach 100%, and the insecticidal activity of abamectin is equivalent. The concentration of 2.5mg·L ^-1 also has a certain lethality to the third instar larvae of Plutella xylostella. The results show that the benzofuro[3,2-d]pyrimidin-2-amine compound synthesized by the synthetic method of this example has good insecticidal activity.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (10)

1. A benzofuran [3,2-d ] pyrimidine-2-amine compound having the formula:

wherein: r is R ¹ Any one selected from phenyl and substituted phenyl; r is R ³ Selected from any one of phenyl, substituted phenyl and naphthyl.

2. Benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 1, having any one of the following structural formulae:

wherein X is halogen,Wherein X is halogen or->

3. The synthesis method of the benzofuran [3,2-d ] pyrimidine-2-amine compound as claimed in claim 1 or 2, which is characterized by comprising the following steps: 2-styryl-3-sulfonamide benzofuran compound, alkali and hydrofluoric acid salt are mixed and stirred in a solvent, and then N-aryl-N-cyano-p-toluenesulfonamide compound is added for synthesis reaction, so that benzofuran [3,2-d ] pyrimidine-2-amine compound is prepared.

4. The method for synthesizing benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 3, wherein: the mass ratio of the 2-styryl-3-sulfonamide benzofuran compound, the N-aryl-N-cyano-p-toluenesulfonyl compound, the alkali and the hydrofluoric acid salt is 1 (1-5): 2-5.

5. The method for synthesizing the benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 4, wherein the method comprises the following steps: the base is selected from any one of potassium carbonate, cesium carbonate, sodium carbonate and triethylamine.

6. The method for synthesizing the benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 5, wherein the method comprises the following steps: the hydrofluoric acid salt is selected from any one of triethylamine hydrofluoric acid salt, pyridine hydrofluoric acid salt and tetra-n-butyl ammonium bifluoride hydrofluoric acid salt.

7. The method for synthesizing the benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 6, wherein the method comprises the following steps: the base is cesium carbonate; the hydrofluoric acid salt is triethylamine hydrofluoric acid salt.

8. The method for synthesizing the benzofuran [3,2-d ] pyrimidine-2-amine compound according to any one of claims 1 to 7, wherein the method comprises the following steps: the mixing and stirring time is 10-30 min; the temperature of the synthesis reaction is between-10 and 50 ℃ and the time is 24 hours.

9. The method for synthesizing the benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 6, wherein the method comprises the following steps: the solvent is selected from any one of acetonitrile, dichloromethane, 1, 2-dichloroethane, toluene, 1, 4-dioxane and ethyl acetate.

10. Use of a benzofuran [3,2-d ] pyrimidine-2-amine compound according to claim 1 in the preparation of a pesticide.