A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide

Abstract

The invention provides a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide, comprising the following steps: adding phenylcyclohexane, a hydrobromic acid solution and an organic solvent in a reaction container in sequence to obtain a mixed solution, placing the mixed solution under visible light, and reacting in pure oxygen or air, controlling the reaction time and the reaction temperature, and obtaining 1-phenylcyclohexyl hydroperoxide after the reaction is completed. The reaction process is as follows:

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis application, and particularly relates to a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide. Background Art

[0002] As important chemical raw materials, phenol and cyclohexanone are mainly used to synthesize fine chemical products such as bisphenol A, phenolic resin, caprolactam and adipic acid. The liquid phase catalytic oxidation of cyclohexylbenzene (CHB) to synthesize phenol and cyclohexanone has good application prospects.

[0003] At present, the cyclohexylbenzene process for producing phenol and cyclohexanone mainly includes two reaction processes: cyclohexylbenzene oxidation to produce 1-phenylcyclohexyl hydroperoxide, and 1-phenylcyclohexyl hydroperoxide acid decomposition to produce phenol and cyclohexanone. Among them, the first reaction process is the focus and difficulty of the whole process. Chemical companies and research institutions at home and abroad have developed technologies related to phenylcyclohexane oxidation and have made certain progress. However, the existing process has many disadvantages, including a long reaction process, relatively harsh conditions, poor selectivity, and the use of oxidants is not environmentally friendly. Summary of the invention

[0004] The present invention is made to solve the above problems, and its purpose is to provide a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide.

[0005] The present invention provides a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide, which has the following characteristics and comprises the following steps: phenylcyclohexane, hydrobromic acid solution and organic solvent are sequentially added into a reaction container to obtain a mixed solution, the mixed solution is then placed under visible light and reacted in pure oxygen or air, the reaction time and reaction temperature are controlled, and 1-phenylcyclohexyl hydroperoxide is obtained after the reaction is completed. The reaction process is as follows:

[0006]

[0007] The light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide provided by the present invention may also have the following characteristics: wherein the organic solvent is a mixture of one or more of dichloromethane, 1,2-dichloroethane, acetonitrile, N,N-dimethylformamide, acetone and ethyl acetate.

[0008] The light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide provided by the present invention may also have the following characteristics: wherein the molar ratio of phenylcyclohexane to hydrobromic acid solution is 100:(0.1-100).

[0009] The light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide provided by the present invention may also have the following characteristics: wherein the wavelength of the light source used for visible light is 365nm-800nm.

[0010] The light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide provided by the present invention may also have the following characteristics: wherein the reaction time is 0.5h-5h.

[0011] The light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide provided by the present invention may also have the following characteristics: wherein the reaction temperature is room temperature.

[0012] Functions and Effects of the Invention

[0013] According to the light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide involved in the present invention, the reaction process is short and the reaction conditions are simple. Oxygen or air is used as an oxidant, and phenylcyclohexane can be selectively oxidized to generate 1-phenylcyclohexyl hydroperoxide in a green, mild and efficient manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a nuclear magnetic resonance spectrum at 400 MHz of 1-phenylcyclohexyl hydroperoxide prepared by a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in Example 1 of the present invention;

[0015] Figure 2 This is the nuclear magnetic resonance spectrum at 101 MHz of 1-phenylcyclohexyl hydroperoxide prepared by a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in Example 1 of the present invention. DETAILED DESCRIPTION

[0016] In order to make the technical means and effects achieved by the present invention easier to understand, the present invention is described in detail below in conjunction with embodiments and drawings.

[0017] <Example 1>

[0018] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps: adding phenylcyclohexane, hydrobromic acid solution and organic solvent in a reaction container in sequence to obtain a mixed solution, placing the mixed solution under visible light, and reacting in pure oxygen or air, controlling the reaction time and reaction temperature, and obtaining 1-phenylcyclohexyl hydroperoxide after the reaction is completed. The reaction process is as follows:

[0019]

[0020] The organic solvent is a mixture of one or more of dichloromethane, 1,2-dichloroethane, acetonitrile, N,N-dimethylformamide, acetone and ethyl acetate. Preferably, the organic solvent is ethyl acetate.

[0021] The molar ratio of phenylcyclohexane to the hydrobromic acid solution is 100:(0.1-100). In this embodiment, the mass fraction of hydrogen bromide in the hydrobromic acid solution is preferably 40%.

[0022] The wavelength of the light source used for the visible light is 365nm-800nm. The visible light is preferably mixed blue light, and the power is preferably 40W.

[0023] The reaction time is 0.5h-5h.

[0024] The reaction temperature is room temperature.

[0025] In this example, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added to the prepared 1-phenylcyclohexyl hydroperoxide, and the mixture was mixed and then taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance measurement. Figure 1 This is a nuclear magnetic resonance spectrum of 1-phenylcyclohexyl hydroperoxide prepared by a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in an embodiment of the present invention at 400 MHz; Figure 2 The figure is a nuclear magnetic resonance spectrum at 101 MHz of 1-phenylcyclohexyl hydroperoxide prepared by a light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in an embodiment of the present invention.

[0026] like Figure 1 and Figure 2 As shown, the NMR spectrum data are as follows:

[0027] 1 H NMR (400MHz, CDCl3): δ7.49 (d, J=8.3Hz, 2H), 7.39 (t, J=7.6Hz, 2H), 7.33–7. 27(m,1H),2.22–2.10(m,2H),1.90–1.66(m,6H),1.60(dt,J=9.2,3.8Hz,2H). 13 C NMR (101MHz, CDCl3): δ144.76,128.63,127.48,125.63,84.48,34.12,25.55,21.94.

[0028] 1-Phenylcyclohexyl hydroperoxide can be successfully produced through the light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide of this embodiment.

[0029] <Example 2>

[0030] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps:

[0031] In a reaction vessel, (CHB, 32.0 mg, 0.2 mmol), hydrobromic acid solution (40 wt.% solution, 1.5 μL) and ethyl acetate (2.0 mL) were added in sequence to obtain a mixed solution, and then the mixed solution was placed under visible light of different wavelengths and reacted in air. The reaction time was controlled to be 3 h, and the reaction temperature was controlled to be room temperature by a fan. After the reaction, 1-phenylcyclohexyl hydroperoxide (1-CHBHP) was obtained, and the solvent was drained, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added, mixed, and taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance measurement, and the phenylcyclohexane conversion rate (%) and 1-CHBHP yield (%) when reacting under different visible light were obtained, as shown in Table 1.

[0032] The reaction process in this embodiment is as follows:

[0033]

[0034] Table 1 Phenylcyclohexane conversion and 1-CHBHP yield under different visible light conditions

[0035]

[0036] As shown in Table 1, when the reaction was carried out under light with a wavelength of 365 nm, light with a wavelength of 400 nm, light with a wavelength of 420 nm, white LED, and blue LED, the conversion rate of phenylcyclohexane was 100%. When the visible light used was blue light, the highest yield of 1-phenylcyclohexyl hydroperoxide that could be obtained was 91%.

[0037] <Example 3>

[0038] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps:

[0039] Phenylcyclohexane (CHB, 32.0 mg, 0.2 mmol), hydrobromic acid solution (40 wt.% solution, 1.5 μL) and different organic solvents (2.0 mL) were added to the reaction container in sequence to obtain a mixed solution, and then the mixed solution was placed under blue light and reacted in the air. The reaction time was controlled to be 3 h, and the reaction temperature was controlled to be room temperature with a fan. After the reaction, 1-phenylcyclohexyl hydroperoxide (1-CHBHP) was obtained, and the solvent was drained, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added, mixed and taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance, and the phenylcyclohexane conversion rate (%) and 1-CHBHP yield (%) using different organic solvents for the reaction were obtained, as shown in Table 2.

[0040] The reaction process in this embodiment is as follows:

[0041]

[0042] Table 2 Phenylcyclohexane conversion and 1-CHBHP yield using different organic solvents

[0043]

[0044]

[0045] As shown in Table 2, in this embodiment, acetonitrile, N,N-dimethylformamide, acetone and ethyl acetate are used as organic solvents for the reaction. When ethyl acetate is used as the organic solvent, the highest phenylcyclohexane conversion rate is 100% and the highest 1-phenylcyclohexyl hydroperoxide yield is 91%.

[0046] <Example 4>

[0047] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps:

[0048] Phenylcyclohexane (CHB, 32.0 mg, 0.2 mmol), hydrobromic acid solution (40 wt.% solution, 15.0 μL) and ethyl acetate (X mL) were added to the reaction container in sequence to obtain a mixed solution, and then the mixed solution was placed under blue light and reacted in pure oxygen. The reaction time was controlled to be 3 h, and the reaction temperature was controlled to be room temperature with a fan. After the reaction, 1-phenylcyclohexyl hydroperoxide (1-CHBHP) was obtained, and the solvent was drained, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added, mixed and taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance measurement, and the phenylcyclohexane conversion rate (%) and 1-CHBHP yield (%) using different volumes of ethyl acetate for the reaction were obtained, as shown in Table 3.

[0049] The reaction process in this embodiment is as follows:

[0050]

[0051] Table 3 Phenylcyclohexane conversion and 1-CHBHP yield using different volumes of ethyl acetate

[0052] Ethyl acetate (XmL) 1.0 2.0 3.0 4.0 Phenylcyclohexane conversion rate (%) 100 100 100 100 1-CHBHP yield (%) 80 91 90 89

[0053] As shown in Table 3, in this embodiment, 1 mL, 2 mL, 3 mL, and 4 mL of ethyl acetate were used for the reaction, respectively. When the volume of ethyl acetate used was 2 mL, the highest phenylcyclohexane conversion rate was 100% and the highest 1-phenylcyclohexyl hydroperoxide yield was 91%.

[0054] <Example 5>

[0055] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps:

[0056] Phenylcyclohexane (CHB, 32.0 mg, 0.2 mmol), hydrobromic acid solution (40 wt.% solution, X mol%) and ethyl acetate (2.0 mL) were added to the reaction container in sequence to obtain a mixed solution, and then the mixed solution was placed under blue light and reacted in pure oxygen. The reaction time was controlled to be 3 h, and the reaction temperature was controlled to be room temperature by a fan. After the reaction, 1-phenylcyclohexyl hydroperoxide (1-CHBHP) was obtained, and the solvent was drained, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added, mixed and taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance, and the phenylcyclohexane conversion rate (%) and 1-CHBHP yield (%) using different mol% hydrobromic acid solutions for reaction were obtained, as shown in Table 4.

[0057] The reaction process in this embodiment is as follows:

[0058]

[0059] Table 4 Phenylcyclohexane conversion and 1-CHBHP yield using different mol% hydrobromic acid solutions

[0060]

[0061] As shown in Table 4, in this embodiment, 2 mol%, 5 mol% and 10 mol% hydrobromic acid solutions were used for the reaction. When 5 mol% hydrobromic acid solution was used, the highest phenylcyclohexane conversion rate was 100% and the highest 1-phenylcyclohexyl hydroperoxide yield was 91%.

[0062] <Example 6>

[0063] A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide in this embodiment comprises the following steps:

[0064] Phenylcyclohexane (CHB, 32.0 mg, 0.2 mmol), hydrobromic acid solution (40 wt.% solution, 15.0 μL), and ethyl acetate (2.0 mL) were added to the reaction container in sequence to obtain a mixed solution, and then the mixed solution was placed under blue light and reacted in pure oxygen. The reaction time was controlled to be X, and the reaction temperature was controlled to be room temperature by a fan. After the reaction, 1-phenylcyclohexyl hydroperoxide (1-CHBHP) was obtained, and the solvent was drained, 1,3,5-trimethoxybenzene (5.6 mg, 0.03 mmol) and deuterated chloroform (0.75 mL) were added, mixed, and taken into a nuclear magnetic resonance tube for crude nuclear magnetic resonance measurement, and the phenylcyclohexane conversion rate (%) and 1-CHBHP yield (%) under different reaction times were obtained, as shown in Table 5.

[0065] The reaction process in this embodiment is as follows:

[0066]

[0067] Table 5 Phenylcyclohexane conversion and 1-CHBHP yield at different reaction times

[0068]

[0069] As shown in Table 5, in this embodiment, the reaction time is controlled to be 0.5h, 1h, 2h, 3h, 4h and 5h respectively. When the reaction time is 3h, the highest phenylcyclohexane conversion rate is 100% and the highest 1-phenylcyclohexyl hydroperoxide yield is 91%.

[0070] In summary, according to Example 2 to Example 6, in the light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide of the present invention, when the reaction is carried out, the visible light is preferably blue light, the organic solvent is preferably ethyl acetate, the amount of ethyl acetate used is preferably 2 mL, the hydrobromic acid solution is preferably 5 mol%, and the reaction time is preferably 3 h. The present invention can selectively oxidize phenylcyclohexane to generate 1-phenylcyclohexyl hydroperoxide in a green, mild and efficient manner, with a phenylcyclohexane conversion rate of up to 100%, and a 1-phenylcyclohexyl hydroperoxide yield of up to 91%.

[0071] Functions and Effects of the Embodiments

[0072] According to the light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide involved in this embodiment, the reaction process is short and the reaction conditions are simple. Oxygen or air is used as the oxidant, and phenylcyclohexane can be selectively oxidized to generate 1-phenylcyclohexyl hydroperoxide in a green, mild and efficient manner.

[0073] The above-mentioned embodiments are preferred examples of the present invention and are not intended to limit the protection scope of the present invention.

Claims

1. A light-mediated synthesis method of 1-phenylcyclohexyl hydroperoxide, characterized in that: The method comprises the following steps: adding phenylcyclohexane, hydrobromic acid solution and organic solvent in a reaction container in sequence to obtain a mixed solution, placing the mixed solution under visible light, and reacting in pure oxygen or air, controlling the reaction time and reaction temperature, and obtaining 1-phenylcyclohexyl hydroperoxide after the reaction is completed. The reaction process is as follows:

2. The method for synthesizing light-mediated 1-phenylcyclohexyl hydroperoxide according to claim 1, characterized in that: in, The organic solvent is a mixture of one or more of dichloromethane, 1,2-dichloroethane, acetonitrile, N,N-dimethylformamide, acetone and ethyl acetate.

3. The method for synthesizing light-mediated 1-phenylcyclohexyl hydroperoxide according to claim 1, characterized in that: in, The molar ratio of the phenylcyclohexane to the hydrobromic acid solution is 100:(0.1-100).

4. The method for synthesizing light-mediated 1-phenylcyclohexyl hydroperoxide according to claim 1, characterized in that: in, The wavelength of the light source used for the visible light is 365nm-800nm.

5. The method for synthesizing 1-phenylcyclohexyl hydroperoxide mediated by light according to claim 1, characterized in that: in, The reaction time is 0.5h-5h.

6. The method for synthesizing 1-phenylcyclohexyl hydroperoxide mediated by light according to claim 1, characterized in that: in, The reaction temperature is room temperature.

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