Sulfoxide-substituted p-menthane compound as well as preparation method and application thereof

Abstract

The invention discloses a sulfoxide-substituted p-menthane compound as well as a preparation method and application thereof. The compound has a structure as shown in a formula I, and can be prepared by hydrosulfide and oxidation reaction of 1-methyl-4-(1-methyl ethyl)-cyclohexene and mercaptans with different substituent groups. The method disclosed by the invention is simple and convenient to operate and mild in condition, and the prepared sulfoxide-substituted p-menthane compound has excellent herbicidal activity and can be used for preventing and treating agricultural weeds. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of agricultural herbicides, and in particular relates to a sulfoxide-substituted p-mentane compound, a preparation method thereof, and use thereof as a herbicide. Background Art

[0002] p-Menthane, also known as 1-isopropyl-4-methylcyclohexane, is a class of monocyclic monoterpenoid compounds. Research on this compound has mainly focused on alcohols, esters and a small amount of nitrogen-containing derivatives. Its biological activity revolves around anti-tumor, insecticidal and penetration-enhancing effects, and no research on herbicidal activity has been found.

[0003] In order to study the herbicidal activity of p-menthane compounds, find compounds with excellent activity and enrich the p-menthane structural system, the present invention is based on the principle of active substructure splicing, takes p-menthane as a guide, introduces sulfur-containing active groups sulfoxide, and designs and synthesizes a novel p-menthane compound containing sulfoxide substitution. Combined with bioassay experimental data, it is concluded that the compounds have excellent herbicidal activity and can be used to prevent agricultural weeds, and the herbicidal effect of most compounds is better than that of the commercially available herbicide glyphosate.

[0004] The sulfoxide-substituted p-menane compound described in the present invention has not been reported in the prior art. Summary of the invention

[0005] The object of the present invention is to provide a sulfoxide-substituted p-mentane compound and a preparation method thereof and use thereof as a herbicide, so as to meet the new requirements for herbicides that are constantly put forward in agriculture.

[0006] To achieve the above object, the technical solution of the present invention is as follows:

[0007] The present invention provides a sulfoxide-substituted p-menthane compound, the structure of which is shown in Formula I:

[0008]

[0009] Where:

[0010] The R group is selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyano, trichloromethyl, trifluoromethyl, -CHF2, -CH2F, -CH2CF3, -CH2CHF2, -CH2CH2F, -SCF3 or -SCHF2.

[0011] Preferably, the R group is selected from cyclopropyl, cyano, trichloromethyl, trifluoromethyl, -CHF2, -CH2F, -CH2CF3, -CH2CHF2, -CH2CH2F, -SCF3 or -SCHF2;

[0012] It is further preferred that the R group is selected from cyclopropyl, cyano, trichloromethyl, trifluoromethyl, -CHF2, -CH2F, -CH2CF3, -CH2CH2F, -SCF3 or -SCHF2;

[0013] Most preferably the R group is selected from trifluoromethyl or -SCF3.

[0014] The synthetic route of the above-mentioned sulfoxide-substituted p-menthane compound I is as follows:

[0015]

[0016] The specific preparation method comprises the following steps:

[0017] The step 1: under catalytic conditions, compound II and compound III undergo a hydrosulfide reaction in a solvent to obtain an intermediate compound IV; wherein compound II is 1-methyl-4-(1-methylethyl)-cyclohexene, and compound III is a thiol compound;

[0018] The step 2: adding an oxidant to react with compound IV to produce a sulfoxide-substituted p-menane compound I.

[0019] Preferably, the solvent in step 1 is selected from any one of dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, ethyl acetate, tetrahydrofuran or dioxane.

[0020] Preferably, the reaction temperature in step 1 is 25-50°C.

[0021] Preferably, the catalyst used in step 1 is selected from any one of B(C6F5)4, [Ph3C][B(C6F5)4], [C5H4NCH3][B(C6F5)4] or [NHEt3][B(Ph)4]; the molar ratio of the catalyst to 1-methyl-4-(1-methylethyl)-cyclohexene (compound II) is (0.01-0.05):1.

[0022] Preferably, in the hydrosulfidation reaction of step 1, the molar ratio of 1-methyl-4-(1-methylethyl)-cyclohexene (compound II) to the thiol compound (compound III) is 1:(1-3).

[0023] Preferably, the hydrosulfide reaction time in step 1 is 2 to 5 hours.

[0024] Preferably, the solvent used in the oxidation reaction in step 2 is selected from any one of methanol, ethanol, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, toluene, ethyl acetate, acetone or acetonitrile.

[0025] Preferably, the temperature used for the oxidation reaction in step 2 is 0 to 50°C.

[0026] Preferably, in step 2, the oxidant is selected from any one of meta-chloroperbenzoic acid, hydrogen peroxide, sodium hypochlorite, sodium periodate or diacetoxyiodobenzene; and the molar ratio of the oxidant to compound II is (1.1-1.5):1.

[0027] Preferably, the oxidation reaction time in step 2 is 1 to 3 hours.

[0028] Preferably, the reaction solution obtained after the oxidation reaction in step 2 is washed with a saturated sodium thiosulfate solution and a saturated sodium bicarbonate solution in sequence, then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography.

[0029] The present invention provides the use of the compound represented by formula I as a herbicide in the agricultural field.

[0030] The invention uses 1-methyl-4-(1-methylethyl)-cyclohexene and a thiol compound as raw materials, and obtains a series of sulfoxide-substituted p-menane compounds with excellent herbicidal activity through catalytic hydrosulfidation and thioether oxidation.

[0031] Compared with the prior art, the technical effects achieved by the present invention are:

[0032] 1. The preparation method of the compound provided by the present invention is simple, the reaction process is short, and the reaction conditions are mild;

[0033] 2. The sulfoxide-substituted p-menthane compound provided by the present invention has a novel structure and has high herbicidal activity even at a lower dosage. It is not only highly efficient, but also reduces the amount of pesticides used, reduces costs, and reduces environmental pollution, showing a good prospect for development and utilization. DETAILED DESCRIPTION

[0034] The present invention is further illustrated below in conjunction with specific examples. It should be understood that these embodiments are only used to illustrate the present invention and do not limit the scope of the present invention. After reading the present invention, modifications of various equivalent forms of the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial sources.

[0035] The specific compounds of formula I are listed in the following examples to illustrate the present invention, but are not intended to limit the present invention. See Table 1 for details.

[0036] Table 1

[0037] serial number R serial number R serial number R serial number R Ⅰ-1 hydrogen Ⅰ-5 Isopropyl Ⅰ-9 Trifluoromethyl Ⅰ-13 <![CDATA[-CH2CHF2]]> Ⅰ-2 methyl Ⅰ-6 Cyclopropyl Ⅰ-10 <![CDATA[-CHF2]]> Ⅰ-14 <![CDATA[-CH2CH2F]]> Ⅰ-3 Ethyl Ⅰ-7 Cyano Ⅰ-11 <![CDATA[-CH2F]]> Ⅰ-15 <![CDATA[-SCF3]]> Ⅰ-4 n-propyl Ⅰ-8 Trichloromethyl Ⅰ-12 <![CDATA[-CH2CF3]]> Ⅰ-16 <![CDATA[-SCHF2]]>

[0038] The synthetic route is as follows:

[0039]

[0040] Example 1: Preparation of Compound I-1

[0041] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol) (purchased from Nanjing Shizhou Biotechnology Co., Ltd.), methyl mercaptan (0.72 g, 15 mmol), B(C6F5)4 (0.17 g, 0.25 mmol), and 20 mL of dichloromethane into a reaction bottle. After stirring at 25°C for 5 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0042] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (0.95 g, 5.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-1 with a yield of 78% and a product content of 98.3%; 1 H NMR (400MHz, CDCl3) δ (ppm) 2.41 (s, 3H), 1.66-1.63 (m, 4H), 1.62-1.45 (m, 4H), 1.37-1.28 (m, 2H), 1.21 (s, 3H), 0.86 (d, J = 6.5Hz, 6H); HRMS (ESI) m / z:calcd for C 11 H 23 OS[M+H] + 203.1465, found 203.1461.

[0043] Example 2: Preparation of Compound I-2

[0044] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), ethanethiol (0.31 g, 5 mmol), B(C6F5)4 (0.14 g, 0.2 mmol) and 20 mL of chloroform into a reaction bottle. After stirring at 30°C for 4 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0045] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of ethyl acetate, cooled to 0-5°C, and m-chloroperbenzoic acid (1.03 g, 6 mmol) was added. After reacting at 10°C for 3 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-2 with a yield of 81% and a product content of 97.8%; 1 H NMR (400MHz, CDCl3) δ (ppm) 2.81 (q, J = 6.8Hz, 2H), 1.70-1.62 (m, 4H), 1.59-1.37 (m ,7H),1.30-1.26(m,2H),1.22(s,3H),0.84(d,J=6.6Hz,6H); HRMS(ESI)m / z:calcd for C 12 H 25 OS[M+H] + 217.1621, found 217.1619.

[0046] Example 3: Preparation of Compound I-3

[0047] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), n-propyl mercaptan (0.76 g, 10 mmol), B(C6F5)4 (0.11 g, 0.15 mmol) and 20 mL of carbon tetrachloride into a reaction bottle. After stirring at 40°C for 3 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0048] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of acetonitrile, cooled to 0-5°C, and m-chloroperbenzoic acid (1.12 g, 6.5 mmol) was added. After reacting at 30°C for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-3 with a yield of 83% and a product content of 98.1%. 1 H NMR (400MHz, CDCl3) δ (ppm) 2.60 (t, J = 6.0Hz, 2H), 1.86-1.79 (m, 2H), 1.68-1.64 (m, 4H), 1.59-1.46 (m, 4H),1.41-1.32(m,2H),1.25(s,3H),1.07(t,J=7.6Hz,3H),0.89(d,J=6.4Hz,6H); HRMS(ESI)m / z:calcd for C 13 H 27 OS[M+H] +231.1778, found 231.1775.

[0049] Example 4: Preparation of Compound I-4

[0050] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), n-butyl mercaptan (0.68 g, 7.5 mmol), B(C6F5)4 (73.3 mg, 0.1 mmol), and 20 mL of 1,2-dichloroethane into a reaction bottle. After stirring at 50°C for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0051] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of toluene, cooled to 0-5°C, and m-chloroperbenzoic acid (1.21 g, 7 mmol) was added. After reacting at 40°C for 1 hour, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-4 with a yield of 79% and a product content of 97.5%; 1 H NMR (400MHz, CDCl3) δ (ppm) 2.60 (t, J = 6.0Hz, 2H), 1.82-1.75 (m, 2H), 1.68-1.55 (m, 6H), 1.52-1.38 (m, 4H),1.34-1.28(m,2H),1.23(s,3H),0.97(t,J=7.6Hz,3H),0.85(d,J=6.5Hz,6H); HRMS(ESI)m / z:calcd for C 14 H 29 OS[M+H] + 245.1934, found 245.1930.

[0052] Example 5: Preparation of Compound I-5

[0053] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), isobutyl mercaptan (1.13 g, 12.5 mmol), B(C6F5)4 (73.3 mg, 0.1 mmol) and 20 mL of ethyl acetate into a reaction bottle. After stirring at 50°C for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0054] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of acetone, cooled to 0-5°C, sodium hypochlorite (0.56 g, 7.5 mmol) was added, and reacted at room temperature for 1 hour. The reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-5 with a yield of 82% and a product content of 98.5%; 1 HNMR (400MHz, CDCl3) δ (ppm) 2.54 (d, J = 5.5Hz, 2H), 2.14-2.07 (m, 1H), 1.70-1.57 (m, 6H), 1.52-1.45 ( m,2H),1.38-1.31(m,2H),1.25(s,3H),1.04(d,J=6.9Hz,6H),0.90-0.84(m,6H); HRMS(ESI)m / z:calcd for C 14 H 29 OS[M+H] + 245.1934, found 245.1933.

[0055] Example 6: Preparation of Compound I-6

[0056] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), cyclopropylmethyl mercaptan (0.67 g, 7.5 mmol), [Ph3C][B(C6F5)4] (46.1 mg, 0.05 mmol) and 20 mL of tetrahydrofuran into a reaction bottle. After stirring at 25°C for 3 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0057] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of 1,2-dichloromethane, cooled to 0-5°C, diacetoxyiodobenzene (1.78 g, 5.5 mmol) was added, and reacted at room temperature for 2 hours. The reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-6 with a yield of 77% and a product content of 98.2%. 1 HNMR(400MHz, CDCl3)δ(ppm)2.63-2.60(m,2H),1.70-1.54(m,6H),1.50-1.31(m,9H),1.24(s,3H),0.88-0.84(m,6H); HRMS(ESI)m / z:calcdfor C 14 H 27 OS[M+H] +243.1778, found 243.1776.

[0058] Example 7: Preparation of Compound I-7

[0059] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), cyanomethylmercaptan (0.55 g, 7.5 mmol), [NHEt3][B(Ph)4] (21.1 mg, 0.05 mmol) and 20 mL of dioxane into a reaction bottle. After stirring at 25°C for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0060] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of carbon tetrachloride, cooled to 0-5°C, diacetoxyiodobenzene (1.94 g, 6 mmol) was added, and reacted at room temperature for 1 hour. The reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-7 with a yield of 80% and a product content of 98.1%; 1 H NMR (400MHz, CDCl3) δ (ppm) 3.78 (s, 2H), 1.67-1.65 (m, 4H), 1.61-1.57 (m, 2H), 1.51- 1.43(m,2H),1.35-1.27(m,2H),1.25(s,3H),0.89-0.86(m,6H); HRMS(ESI)m / z:calcd for C 12 H 22 NOS[M+H] + 228.1417, found 228.1413.

[0061] Example 8: Preparation of Compound I-8

[0062] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), trichloromethyl methyl mercaptan (1.64 g, 10 mmol), [Ph3C][B(C6F5)4] (46.1 mg, 0.05 mmol) and 20 mL of chloroform into a reaction bottle. After stirring at 40°C for 1 hour, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0063] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of methanol, cooled to 0-5°C, and hydrogen peroxide (0.26 g, 7.5 mmol) was added. After reacting at 50°C for 1 hour, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-8 with a yield of 76% and a product content of 98.3%; 1 H NMR (400MHz, CDCl3) δ (ppm) 3.65 (s, 2H), 1.69-1.66 (m, 4H), 1.61-1.57 (m, 2H), 1.54-1. 42(m,2H),1.36-1.30(m,2H),1.21(s,3H),0.87(d,J=6.5Hz,6H); HRMS(ESI)m / z:calcd for C 12 H 22 Cl3OS[M+H] + 319.0452, found 319.0451.

[0064] Example 9: Preparation of Compound I-9

[0065] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), trifluoromethyl methyl mercaptan (1.14 g, 10 mmol), [Ph3C][B(C6F5)4] (46.1 mg, 0.05 mmol) and 20 mL of dichloromethane into a reaction bottle. After stirring at room temperature for 1 hour, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0066] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-9 with a yield of 83% and a product content of 97.9%; 1 H NMR (400MHz, CDCl3) δ (ppm) 3.36 (q, J = 9.1Hz, 2H), 1.65-1.55 (m, 6H), 1.55-1.41 (m ,2H),1.36-1.29(m,2H),1.24(s,3H),0.89(d,J=6.7Hz,6H); HRMS(ESI)m / z:calcd for C 12 H 22 F3OS[M+H] +271.1338, found 271.1334.

[0067] Example 10: Preparation of Compound I-10

[0068] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), difluoromethyl methyl mercaptan (0.98 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of dichloromethane into a reaction bottle. After stirring at room temperature for 1 hour, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0069] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of ethanol, cooled to 0-5°C, sodium periodate (1.28 g, 6 mmol) was added, and the reaction was carried out at room temperature for 2 hours. The reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-10 with a yield of 81% and a product content of 98.3%; 1 HNMR (400MHz, CDCl3) δ (ppm) 6.68-6.44 (m, 1H), 2.92 (td, J = 20.9, 1.8Hz, 2H), 1.63-1.57 (m, 6H) ,1.52-1.42(m,2H),1.38-1.31(m,2H),1.22(s,3H),0.86(d,J=6.4Hz,6H); HRMS(ESI)m / z:calcd for C 12 H 23 F2OS[M+H] + 253.1433, found 253.1431.

[0070] Example 11: Preparation of Compound I-11

[0071] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), monofluoromethyl methyl mercaptan (0.80 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of chloroform into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0072] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of chloroform, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-11 with a yield of 75% and a product content of 97.7%; 1 H NMR (400MHz, CDCl3) δ (ppm) 4.87 (dt, J=46.3, 4.8Hz, 2H), 2.88 (dt, J=25.3, 4.9Hz, 2H), 1.66-1.54 ( m,6H),1.52-1.43(m,2H),1.37-1.30(m,2H),1.20(s,3H),0.87-0.83(m,6H); HRMS(ESI)m / z:calcd for C 12 H 24 FOS[M+H] + 235.1527, found 235.1525.

[0073] Example 12: Preparation of Compound I-12

[0074] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), trifluoroethyl methyl mercaptan (1.30 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of chloroform into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0075] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-12 with a yield of 78% and a product content of 98.2%. 1 H NMR (400MHz, CDCl3) δ (ppm) 2.81 (t, J = 7.0Hz, 2H), 2.68-2.59 (m, 2H), 1.66 (td, J = 6.8, 0.9Hz, 4H), 1.62- 1.54(m,2H),1.52-1.45(m,2H),1.40-1.34(m,2H),1.25(s,3H),0.88-0.84(m,6H); HRMS(ESI)m / z:calcd for C13 H 24 F3OS[M+H] + 285.1495, found 285.1491.

[0076] Example 13: Preparation of Compound I-13

[0077] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), difluoroethyl methyl mercaptan (1.12 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of chloroform into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0078] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-13 with a yield of 81% and a product content of 98.1%. 1 H NMR (400MHz, CDCl3) δ (ppm) 5.67-5.43 (m, 1H), 2.77 (t, J = 6.9Hz, 2H), 2.26-2.15 (m, 2H), 1.70-1.66 (m, 4H), 1.6 3-1.55(m,2H),1.49-1.40(m,2H),1.35-1.29(m,2H),1.23(s,3H),0.85(d,J=6.5Hz,6H); HRMS(ESI)m / z:calcd forC 13 H 25 F2OS[M+H] + 267.1589, found 267.1588.

[0079] Example 14: Preparation of Compound I-14

[0080] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), monofluoroethyl methyl mercaptan (0.94 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of dichloromethane into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0081] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-14 with a yield of 76% and a product content of 97.9%; 1 H NMR (400MHz, CDCl3) δ (ppm) 4.51 (dt, J = 46.3, 5.6Hz, 2H), 2.61 (t, J = 6.0Hz, 2H), 2.24-2.14 (m, 2H), 1.68- 1.54(m,6H),1.52-1.48(m,2H),1.32-1.28(m,2H),1.21(s,3H),0.86-0.82(m,6H); HRMS(ESI)m / z:calcd for C 13 H 26 FOS[M+H] + 249.1683, found 249.1681.

[0082] Example 15: Preparation of Compound I-15

[0083] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), trifluoromethylthiomethylthiol (1.48 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of dichloromethane into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0084] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-15 with a yield of 80% and a product content of 98.4%. 1 H NMR (400MHz, CDCl3) δ (ppm) 3.97 (s, 2H), 1.70-1.62 (m, 4H), 1.58-1.49 (m, 4H), 1.40-1.33 (m, 2H), 1.25 (s, 3H), 0.90-0.86 (m, 6H); HRMS (ESI) m / z:calcd for C 12 H 22 F3OS2[M+H]+ 303.1059, found 303.1056.

[0085] Example 16: Preparation of Compound I-16

[0086] Step 1: Add 1-methyl-4-(1-methylethyl)-cyclohexene (Compound II) (0.69 g, 5 mmol), trifluoroethylthiomethylmercaptan (1.62 g, 10 mmol), [Ph3C][B(C6F5)4] (92.2 mg, 0.1 mmol) and 20 mL of dichloromethane into a reaction bottle. After stirring at room temperature for 2 hours, the reaction solution was filtered through diatomaceous earth and concentrated under reduced pressure.

[0087] Step 2: The concentrate obtained in step 1 was dissolved in 20 ml of dichloromethane, cooled to 0-5°C, and m-chloroperbenzoic acid (1.30 g, 7.5 mmol) was added. After reacting at room temperature for 2 hours, the reaction solution was washed with saturated sodium thiosulfate solution (10 ml) and saturated sodium bicarbonate solution (10 ml) in sequence, and then dried over anhydrous sodium sulfate, concentrated under reduced pressure, and separated by column chromatography to obtain compound I-16 with a yield of 77% and a product content of 98.3%; 1 H NMR (400MHz, CDCl3) δ (ppm) 3.35 (t, J = 4.8Hz, 2H), 2.94 (t, J = 4.8Hz, 2H), 1.65-1.56 (m, 6H), 1.51-1.43(m,2H),1.38-1.31(m,2H),1.24(s,3H),0.89-0.85(m,6H); HRMS(ESI)m / z:calcd for C 13 H 24 F3OS2[M+H] + 317.1216 found 317.1215.

[0088] Example 17: Test of herbicidal activity of compounds

[0089] 40-50 seeds of zinnia, velvetleaf, foxtail grass and barnyard grass were sown in a plastic pot with a diameter of 8 cm, covered with 1-2 mm of soil, and placed in an enamel dish filled with water to allow water to gradually penetrate. After the water seeped to the soil surface, the pot was transferred to a glass greenhouse for cultivation. When the weeds had 2-3 leaves, the seedlings were determined. 30 plants were determined in each pot. Water was regularly infiltrated from the bottom of the pot to maintain soil moisture. Each compound was set at 100 and 500 g ai / hm 2 Treatment. The test compound was dissolved in an appropriate amount of acetone, and then diluted to 500 mg / l with a 0.1% Tween-80 aqueous solution. The stems and leaves of the above-mentioned weeds were evenly sprayed at the 2-3 true leaf stage. The fresh weight of the above-ground part of each treated weed was weighed 20 days after the application, and the fresh weight control effect was calculated. The results are shown in Table 2.

[0090] Calculate the fresh weight control effect of each treatment according to the formula:

[0091] Inhibition rate / % = [fresh weight of control area - fresh weight of treatment area] / fresh weight of control area × 100

[0092] Table 2 Herbicidal activity of target compounds in potted plants (gai / hm 2 )

[0093]

Claims

1. A sulfoxide-substituted p-menthane compound, characterized in that: The compound has the structure shown in Formula I: wherein: the R substituent is selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, cyclopropyl, cyano, trichloromethyl, trifluoromethyl, -CHF2, -CH2F, -CH2CF3, -CH2CHF2, -CH2CH2F, -SCF3 or -SCHF2.

2. A method for preparing the sulfoxide-substituted p-menthane compound I according to claim 1, characterized in that: Its synthetic route is as follows: The step 1: under catalytic conditions, compound II and compound III undergo a hydrosulfide reaction in a solvent to obtain an intermediate compound IV; wherein compound II is 1-methyl-4-(1-methylethyl)-cyclohexene, and compound III is a thiol compound; The step 2: adding an oxidant to react with compound IV to produce a sulfoxide-substituted p-mentane compound.

3. The preparation method according to claim 2, characterized in that: In the step 1, the solvent is selected from any one of dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, ethyl acetate, tetrahydrofuran or dioxane.

4. The preparation method according to claim 2, characterized in that: The temperature used in the reaction of step 1 is 25-50° C., and the hydrosulfide reaction time is 2-5 hours.

5. The preparation method according to claim 2, characterized in that: The catalyst used in step 1 is selected from any one of B(C6F5)4, [Ph3C][B(C6F5)4], [C5H4NCH3][B(C6F5)4] or [NHEt3][B(Ph)4]; the molar ratio of the catalyst to 1-methyl-4-(1-methylethyl)-cyclohexene is (0.01-0.05):

1.

6. The preparation method according to claim 2, characterized in that: In the step 1, the molar ratio of the compound 1-methyl-4-(1-methylethyl)-cyclohexene to the thiol compound is 1:(1-3).

7. The preparation method according to claim 2, characterized in that: The solvent used in the oxidation reaction in step 2 is selected from any one of methanol, ethanol, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, toluene, ethyl acetate, acetone or acetonitrile.

8. The preparation method according to claim 2, characterized in that: The temperature used for the oxidation reaction in step 2 is 0 to 50° C., and the time for the oxidation reaction is 1 to 3 hours.

9. The preparation method according to claim 2, characterized in that: In step 2, the oxidant is selected from any one of meta-chloroperbenzoic acid, hydrogen peroxide, sodium hypochlorite, sodium periodate or diacetoxyiodobenzene; and the molar ratio of the oxidant to compound II is (1.1-1.5):

1.

10. Use of the sulfoxide-substituted p-mentane compound according to claim 1 as a herbicide.

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