Method for preparing bisphenol A and heterocyclic compound from waste PC

Abstract

The invention discloses a method for preparing bisphenol A and a heterocyclic compound by utilizing waste PC (polycarbonate), and belongs to the technical field of solid waste recycling, the method comprises the following steps: constructing a reaction system by utilizing crushed waste PC, an aminobenzonitrile compound, an alkali catalyst and a solvent, and reacting the reaction system at the temperature of 100-160 DEG C for more than or equal to 30 minutes in an air atmosphere to obtain the bisphenol A and heterocyclic compound. According to the method, bisphenol A and a heterocyclic compound are taken as raw materials, and the heterocyclic compound is quinazoline-2, 4 (1H, 3H)-diketone or a derivative of quinazoline-2, 4 (1H, 3H)-diketone; the amino benzonitrile compounds comprise 2-amino benzonitrile, 2-amino-5-fluorobenzonitrile, 2-amino-4-chlorobenzonitrile and the like; the solvent comprises water and an organic solvent. According to the method, double upgrading conversion of the waste PC can be achieved, the reaction products bisphenol A and the quinazoline-2, 4 (1H, 3H)-diketone compound can be obtained at the same time, the reaction condition is mild, the reaction speed is high, and the method has wide application prospects in the aspect of high-value utilization of the waste PC.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste recycling, and in particular relates to a method for preparing bisphenol A and heterocyclic compounds by utilizing waste PC. Background Art

[0002] Polycarbonate (PC) is an important thermoplastic engineering plastic with excellent physical and mechanical properties, chemical resistance, heat resistance and low temperature resistance. It is widely used in optical instruments, automobile industry, construction industry, electronic products, medical field, packaging industry, aerospace and other fields. The recycling of waste PC is not only beneficial to environmental protection and reducing the risk of soil and water pollution, but also realizes resource reuse, has high economic benefits, and can promote technological innovation and industrial upgrading. At present, waste PC is mainly recycled mechanically, but with the increase in the number of recycling times, the product quality and performance gradually decrease, causing this method to become downgraded recycling. In contrast, chemical upgrading of waste PC can convert it into high-value-added chemical monomers with higher economic benefits. Waste PC hydrolysis reaction, alcoholysis reaction, glycolysis reaction, pyrolysis reaction, etc. are all key processes for realizing the chemical recycling of waste polycarbonate materials. However, the above reactions usually only produce a single chemical monomer, and the full and effective utilization of carbon resources is not achieved.

[0003] Heterocyclic compounds are organic compounds containing heterocyclic structures in their molecules, and are commonly found in the structure of drug molecules. Quinazoline-2,4(1H,3H)-dione and its derivatives are important heterocyclic compounds that have been widely used in the pharmaceutical and biotechnology industries. Quinazoline-2,4(1H,3H)-dione is an important intermediate in the pharmaceutical industry. It is the core structure for the synthesis of fenacinostat and thioquinafil, alfuzosin, prazosin, terazosin and doxazosin. The corresponding product drugs can be used to treat diabetes, kidney disease, heart disease, hypertension and other diseases. In addition, 6,7-dimethoxyquinazoline-2,4(1H,3H)-dione derivatives are drug sources for the synthesis of α1-adrenergic receptor antagonists, which are used to treat hypertension. At present, there are many methods for synthesizing quinazoline-2,4 (1H, 3H) -dione and its derivatives. For example, Chinese patent document with publication number CN108863952A discloses a method for synthesizing 2,4 (1H, 3H) -quinazoline dione and its derivatives using CO2 and aminophenylacetonitrile compounds as raw materials and salt lake brine as catalyst; Chinese patent document with publication number CN106946800A discloses a method for preparing the product quinazoline-2,4 (1H, 3H) -dione and its derivatives by carboxyl cyclization reaction under carbon dioxide atmosphere using o-aminobenzonitrile or its derivatives substituted at positions 4 and 5 as substrate and diethanolamine aqueous solution as catalyst; However, the above methods all need to be carried out under a pressure condition of 0.5-2MPa, and the reaction needs to be pressurized, which is not conducive to the occurrence of the reaction under normal pressure.

[0004] A variety of methods for recovering bisphenol A from waste PC have been reported in the prior art, such as Chinese patent documents with publication numbers CN118164826A and CN108607604A, etc. However, there has been no report on simultaneously upgrading waste PC to bisphenol A and quinazoline-2,4(1H,3H)-dione and its derivatives. As mentioned above, the current methods for synthesizing quinazoline-2,4(1H,3H)-dione and its derivatives usually need to be carried out under pressurized conditions, and reactions under normal pressure are rare. Summary of the invention

[0005] In view of the demand for high-value utilization of PC waste plastics and the problems existing in the synthesis process of quinazoline-2,4(1H,3H)-dione and its derivatives, the present invention provides a method for preparing bisphenol A and quinazoline-2,4(1H,3H)-dione and its derivatives from waste PC with the participation of 2-aminobenzonitrile. The reaction can be carried out under normal pressure and has a fast reaction speed, thereby achieving full utilization of carbon resources in PC waste plastics.

[0006] The specific technical solutions adopted are as follows: A method for preparing bisphenol A and heterocyclic compounds using waste PC comprises the following steps: A reaction system is constructed using crushed waste polycarbonate PC plastic (bisphenol A type polycarbonate), aminobenzonitrile compounds, a base catalyst and a solvent, and the reaction system is placed at a temperature of 100 to 160° C. in an air atmosphere for a reaction of ≥30 min to obtain a product bisphenol A and a heterocyclic compound, wherein the heterocyclic compound is quinazoline-2,4(1H,3H)-dione or a derivative thereof; The aminobenzonitrile compounds include 2-aminobenzonitrile, 2-amino-5-fluorobenzonitrile, 2-amino-4-chlorobenzonitrile, 2-amino-5-chlorobenzonitrile, 2-amino-5-bromobenzonitrile, 2-amino-4-methylbenzonitrile, 2-amino-5-methylbenzonitrile or 2-amino-4,5-dimethoxybenzonitrile; The base catalyst is an inorganic base or an organic base; Solvents include water and organic solvents.

[0007] The method of the present invention is an economical and green reaction path. It uses waste PC as a CO2 source for the simultaneous high-value reaction of aminobenzonitrile compounds, which can solve the problems of incomplete hydrolysis of PC and low efficiency. In addition, by utilizing the reaction process of the present invention, bisphenol A and quinazoline-2,4(1H,3H)-dione or its derivatives can be prepared simultaneously, and the upgraded conversion of waste PC into two high-value-added chemical monomers can be achieved in one step, effectively and fully utilizing carbon resources.

[0008] Optionally, the organic base includes 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 4-dimethylaminopyridine (DMAP), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD), 1,4-diazabicyclo[2.2.2]octane (DABCO), triethylenediamine (TEDA) or N,N - diisopropylethylamine (DIPEA); the inorganic base includes sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium carbonate or cesium carbonate. The base catalyst is further preferably DBU, TBD, cesium hydroxide or cesium carbonate. Experiments have shown that the above four base catalysts have higher catalytic activity.

[0009] Optionally, the organic solvent is N -Methylpyrrolidone, N,N -dimethylformamide or N,N - one of dimethylacetamide, more preferably N-Methylpyrrolidone, in the solvent, the mass ratio of water to organic solvent is 0.0005-0.15:1. When no water is added, the yield of quinazoline-2,4(1H,3H)-dione compounds will be affected. The combination of water and organic solvent helps the reaction raw materials and catalyst to play a role, so that the carbon resources in waste PC can be fully and effectively converted.

[0010] Preferably, the molar ratio of the aminobenzonitrile compound to the waste PC is 0.5 to 3:1, further 1.2 to 3:1; based on the molar number of the aminobenzonitrile compound as 100%, the molar number of the base catalyst added is 1% to 50%, further 7% to 50% (mol / mol).

[0011] Preferably, the ratio of the solvent to the waste PC is 1-5 mL:1 mmol, further 2-2.5 mL:1 mmol.

[0012] Preferably, the reaction time is 30 min to 12 h, further 1 to 6 h.

[0013] Waste PC can be pure PC or PC waste, including PC waste CDs, PC waste buckets, PC waste films, PC waste bottles, PC waste plates, PC waste sheets, PC waste lamps, etc. The method of the present invention is applicable to various forms of waste PC samples, so that the recovery rate of quinazoline-2,4(1H,3H)-dione or its derivatives can be as high as 93%, showing excellent efficiency and adaptability.

[0014] When upgrading and converting waste PC, it needs to be pre-crushed into centimeter-sized flakes, particles or powders to ensure the resource utilization effect of waste PC and to obtain bisphenol A and quinazoline-2,4(1H,3H)-dione or its derivatives in a targeted manner with high yield.

[0015] Specifically, the product heterocyclic compound includes quinazoline-2,4(1H,3H)-dione, 6-fluoroquinazoline-2,4(1H,3H)-dione, 7-chloroquinazoline-2,4(1H,3H)-dione, 6-chloroquinazoline-2,4(1H,3H)-dione, 6-bromoquinazoline-2,4(1H,3H)-dione, 6-methylquinazoline-2,4(1H,3H)-dione, 7-methylquinazoline-2,4(1H,3H)-dione or 6,7-dimethoxyquinazoline-2,4(1H,3H)-dione, etc. The method of the present invention can prepare various types of quinazoline-2,4(1H,3H)-dione compounds, and the functional groups contained in the quinazoline-2,4(1H,3H)-dione compounds can be further upgraded and transformed by using them.

[0016] Specifically, the method of the present invention can be carried out under normal pressure without applying additional pressure. Normal pressure generally refers to 0.09-0.11 MPa, which greatly reduces the reaction pressure compared with the method for synthesizing quinazoline-2,4(1H,3H)-dione or its derivatives in the prior art.

[0017] Specifically, under standard reaction conditions, 0.254 g PC (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), 0.0608 g DBU (0.4 mmol), 0.02 g water and N -Methylpyrrolidone (2 mL) was reacted at 130°C for 4 hours to obtain bisphenol A and quinazoline-2,4(1H,3H)-dione. The yields of quinazoline-2,4(1H,3H)-dione were 95% and 99%.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) Compared with other methods for synthesizing quinazoline-2,4(1H,3H)-dione compounds, the present invention has simpler and milder reaction conditions and a faster reaction speed. The representative methods for synthesizing quinazoline-2,4(1H,3H)-dione in the prior art require CO2, high temperature and high pressure or expensive catalysts to achieve a yield of 99%, while the method of the present invention only requires the addition of 20% mol / mol (based on the molar number of aminobenzonitrile compounds as 100%) of DBU catalyst and only takes 4 hours at 130°C and normal pressure to achieve a yield of 95%.

[0019] (2) The method of the present invention can further expand the reaction products, not only limited to quinazoline-2,4(1H,3H)-dione, but also can prepare a variety of products including 6-fluoroquinazoline-2,4(1H,3H)-dione, 7-chloroquinazoline-2,4(1H,3H)-dione, 6-chloroquinazoline-2,4(1H,3H)-dione, 6-bromoquinazoline-2,4(1H,3H)-dione, 6-methylquinazoline-2,4(1H,3H)-dione, 7-methylquinazoline-2,4(1H,3H)-dione, and 6,7-dimethoxyquinazoline-2,4(1H,3H)-dione.

[0020] (3) The method of the present invention can achieve dual upgrading and conversion of waste PC, and can simultaneously obtain the reaction products bisphenol A and quinazoline-2,4(1H,3H)-dione compounds, and bisphenol A and quinazoline-2,4(1H,3H)-dione compounds are easy to separate. These two reaction products can be further used to synthesize functional chemicals as high-value-added chemical monomers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1The reaction scheme of the representative embodiment 1 is shown in FIG.

[0022] Figure 2 This is the H NMR spectrum of the reaction product, bisphenol A.

[0023] Figure 3 This is the carbon NMR spectrum of the reaction product bisphenol A.

[0024] Figure 4 This is the H NMR spectrum of the reaction product quinazoline-2,4(1H,3H)-dione.

[0025] Figure 5 This is the carbon NMR spectrum of the reaction product quinazoline-2,4(1H,3H)-dione. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the examples and accompanying drawings. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods of the following examples that do not specify specific conditions are usually performed under normal conditions or under conditions recommended by the manufacturer. The content that is not described in detail in this specification sheet belongs to the prior art known to professionals in the field. The experimental materials used in the following examples, if not otherwise specified, can be purchased by conventional biochemical reagent companies.

[0027] The reaction processes of the following examples and comparative examples were all carried out under normal pressure without applying additional pressure.

[0028] Comparative Example 1 0.254 g CR-purity PC powder (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), 0.02 g water and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130°C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. 60 µL of the resulting mixed solution was taken, and 600 µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometry. The results showed that no product quinazoline-2,4(1H,3H)-dione and bisphenol A were generated.

[0029] Comparative Example 2 In a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple, and a programmable temperature controller, 0.254 g of CR-pure PC powder (1 mmol), 0.236 g of 2-aminobenzonitrile (2 mmol), 0.0608 g of DBU (0.4 mmol) and N-Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130°C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. 60µL of the resulting mixed solution was taken, and 600µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometry. The results showed that the yield of the product quinazoline-2,4(1H,3H)-dione was 36%, and the yield of bisphenol A was 99%.

[0030] Example 1 0.254 g CR-purity PC powder (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), 0.0608 g DBU (0.4 mmol), 0.02 g water and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130°C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. 60 µL of the resulting mixed solution was taken, and 600 µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometry. The results showed that the yield of quinazoline-2,4(1H,3H)-dione was 95%, and the yield of bisphenol A was 99%.

[0031] The reaction scheme of the present invention is as follows Figure 1 As shown, specifically, the method for separating bisphenol A and quinazoline-2,4(1H,3H)-dione is: adding ethyl acetate and water to the mixed solution obtained after the reaction is completed, and quinazoline-2,4(1H,3H)-dione is insoluble in water and ethyl acetate and is directly precipitated, and bisphenol A is further separated by column chromatography.

[0032] The hydrogen nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the product bisphenol A are as follows: Figure 2 and Figure 3 As shown, the hydrogen nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of the product quinazoline-2,4(1H,3H)-dione are as follows: Figure 4 and Figure 5 shown.

[0033] Example 2 In a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple, and a programmable temperature controller, 0.254 g of CR-pure PC powder (1 mmol), different molar amounts of 2-aminobenzonitrile (0.5, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.5, 3 mmol), DBU (0.4 mmol), 0.02 g of water, and N-Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, 60 µL of the resulting mixed solution was taken, and 600 µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometer. The results showed that the yields of quinazoline-2,4 (1H, 3H) -dione in this example were 19%, 39%, 63%, 67%, 77%, 87%, 95%, 92%, 89%, respectively, and the yields of bisphenol A were 92%, 92%, 94%, 94%, 95%, 95%, 99%, 99% and 99%.

[0034] Example 3 Into a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple and a programmable temperature controller were added 0.254 g of CR-pure PC powder (1 mmol), 0.236 g of 2-aminobenzonitrile (2 mmol), different molar amounts of DBU (3%, 5%, 7%, 10%, 15%, 20%, 25%, 30%, 40% and 50% mol / mol, based on the molar number of 2-aminobenzonitrile as 100%), 0.02 g of water and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yields of quinazoline-2,4 (1H, 3H) -dione in this example are 33%, 40%, 64%, 71%, 88%, 95%, 95%, 94%, 93%, 93%, respectively, and the yields of bisphenol A are 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99%, and 99%.

[0035] Example 4 In a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple and a programmable temperature controller, 0.254 g of CR-pure PC powder (1 mmol), 0.236 g of 2-aminobenzonitrile (2 mmol), different base catalysts (DBU, TBD, DBN, DMAP, MTBD, DABCO, TEDA, DIPEA, sodium hydroxide, potassium hydroxide, cesium hydroxide, sodium carbonate, potassium carbonate and cesium carbonate) (0.4 mmol), 0.02 g of water and N-Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yields of quinazoline-2,4 (1H, 3H)-dione in this example are 95%, 83%, 61%, 76%, 73%, 77%, 65%, 73%, 66%, 69%, 95%, 20%, 60% and 92%, respectively, and the yields of bisphenol A are 99%, 96%, 95%, 96%, 94%, 96%, 96%, 97%, 96%, 97%, 99%, 94%, 94% and 99%.

[0036] Example 5 0.254 g CR purity PC powder (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), DBU (0.4 mmol), 0.02 g water and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to different temperatures (100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C), and reacted at the corresponding temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. 60 µL of the resulting mixed solution was taken, and 600 µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometer. The results showed that the yields of quinazoline-2,4(1H,3H)-dione in this example were 85%, 90%, 90%, 95%, 92%, 92% and 88%, respectively, and the yields of bisphenol A were 99%, 99%, 99%, 99%, 99%, 99%, 99% and 99%.

[0037] Example 6 The discarded PC plastics (buckets, sun panels, PC lamps and transparent panels) were crushed to centimeter level in advance, and then 0.254 g of the centimeter-level crushed materials of the above PC plastics (about 1 mmol), 0.236 g of 2-aminobenzonitrile (2 mmol), DBU (0.4 mmol), 0.02 g of water and N-Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yields of quinazoline-2,4 (1H, 3H) -dione in this example are 88%, 94%, 94% and 93%, respectively, and the yields of bisphenol A are 96%, 99%, 99% and 99%.

[0038] Example 7 In a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple and a programmable temperature controller, 0.254 g of CR-purity PC powder (1 mmol), 0.236 g of 2-aminobenzonitrile (2 mmol), DBU (0.4 mmol), different masses of water (0.25 g, 0.20 g, 0.15 g, 0.1 g, 0.06 g, 0.04 g, 0.02 g, 0.008 g, 0.004 g, 0.002 g) and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C and reacted at this temperature for 4 hours. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yields of quinazoline-2,4 (1H, 3H)-dione in this example are 69%, 71%, 77%, 84%, 85%, 86%, 95%, 87%, 84% and 78%, respectively, and the yields of bisphenol A are 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99%, 99% and 99%.

[0039] Example 8 In a pressure tube reactor equipped with an electromagnetic stirrer, a thermocouple and a programmable temperature controller, 0.254 g of PC (1 mmol), different 2-aminobenzonitrile derivatives (2-amino-5-fluorobenzonitrile, 2-amino-4-chlorobenzonitrile, 2-amino-5-chlorobenzonitrile, 2-amino-5-bromobenzonitrile, 2-amino-4-methylbenzonitrile, 2-amino-5-methylbenzonitrile, 2-amino-4,5-dimethoxybenzonitrile) (2 mmol), 0.0608 g of DBU (0.4 mmol), 0.02 g of water and N-methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130°C and reacted at this temperature for 4 hours. After the reaction was completed, the temperature was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yield of quinazoline-2,4(1H,3H)-dione compounds in this example (6-fluoroquinazoline-2,4(1H,3H)-dione, 7-chloroquinazoline-2,4(1H,3H)-dione, 6-chloroquinazoline-2,4(1H,3H)-dione, 6-bromoquinazoline-2,4(1H,3H)- The yields of bisphenol A were 94%, 97%, 96%, 99%, 96%, 97% and 98% respectively.

[0040] Example 9 0.254 g PC (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), 0.0608 g DBU (0.4 mmol), 0.02 g water and N -Methylpyrrolidone (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130 ° C, and reacted at this temperature for 1, 2, 3, 4, 5 and 6 hours respectively. After the reaction was completed, it was cooled to room temperature, and the resulting mixed solution was the product. Take 60 µL of the resulting mixed solution, add 600 µL of deuterated DMSO, and measure the yield by nuclear magnetic resonance spectrometer. The results show that the yields of quinazoline-2,4 (1H, 3H) -dione in this example are 72%, 77%, 87%, 95%, 94%, 95%, respectively, and the yields of bisphenol A are 99%, 99%, 99%, 99%, 99%, 99% and 99%.

[0041] Example 10 0.254 g CR-purity PC powder (1 mmol), 0.236 g 2-aminobenzonitrile (2 mmol), DBU (0.4 mmol), 0.02 g water and different solvents ( N -Methylpyrrolidone, N,N -dimethylformamide, N,N-dimethylacetamide, 1,4-dioxane, acetonitrile, dimethyltetrahydrofuran) (2 mL), after placing the pressure tube reactor, start stirring and heating. The reaction system was heated to 130°C and reacted at this temperature for 4 hours. After the reaction was completed, the temperature was cooled to room temperature, and the resulting mixed solution was the product. 60 µL of the resulting mixed solution was taken, and 600 µL of deuterated DMSO was added. The yield was determined by nuclear magnetic resonance spectrometry. The results showed that the yields of quinazoline-2,4(1H,3H)-dione in this example were 95%, 93%, 90%, 11%, 3% and 6%, respectively, and the yields of bisphenol A were 99%, 99%, 99%, 87%, 80% and 93%, respectively.

[0042] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing bisphenol A and heterocyclic compounds using waste PC, characterized in that: The following steps are involved: A reaction system is constructed by using crushed waste polycarbonate PC plastic, aminobenzonitrile compounds, a base catalyst and a solvent, and the reaction system is placed at a temperature of 100 to 160° C. in an air atmosphere for a reaction of ≥30 min to obtain bisphenol A and a heterocyclic compound, wherein the heterocyclic compound is quinazoline-2,4(1H,3H)-dione or a derivative thereof; The aminobenzonitrile compounds include 2-aminobenzonitrile, 2-amino-5-fluorobenzonitrile, 2-amino-4-chlorobenzonitrile, 2-amino-5-chlorobenzonitrile, 2-amino-5-bromobenzonitrile, 2-amino-4-methylbenzonitrile, 2-amino-5-methylbenzonitrile or 2-amino-4,5-dimethoxybenzonitrile; The base catalyst is an inorganic base or an organic base; Solvents include water and organic solvents.

2. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The organic base includes 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, 4-dimethylaminopyridine, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1,4-diazabicyclo[2.2.2]octane, triethylenediamine or N,N -diisopropylethylamine; the inorganic base includes sodium hydroxide, potassium hydroxide, cesium hydroxide, potassium carbonate or cesium carbonate.

3. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The organic solvent is N -Methylpyrrolidone, N,N -dimethylformamide or N,N - one of dimethylacetamide, in which the mass ratio of water to organic solvent is 0.0005-0.15:

1.

4. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The molar ratio of the aminobenzonitrile compound to the waste PC is 0.5-3:

1. Taking the molar number of the aminobenzonitrile compound as 100%, the molar number of the added alkali catalyst is 1%-50%.

5. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The ratio of solvent to waste PC is 1-5 mL:1 mmol.

6. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The molar ratio of the aminobenzonitrile compound to the waste PC is 1.2-3:1, and the molar number of the base catalyst added is 7%-50% based on the molar number of the aminobenzonitrile compound as 100%; the ratio of the solvent to the waste PC is 2-2.5 mL:1mmol.

7. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The reaction time is 30 min to 12 h.

8. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: Waste PC includes waste PC bottles, waste PC plates, waste PC sheets, waste PC lamps or waste PC films.

9. The method for preparing bisphenol A and heterocyclic compounds using waste PC according to claim 1, characterized in that: The product heterocyclic compounds include quinazoline-2,4(1H,3H)-dione, 6-fluoroquinazoline-2,4(1H,3H)-dione, 7-chloroquinazoline-2,4(1H,3H)-dione, 6-chloroquinazoline-2,4(1H,3H)-dione, 6-bromoquinazoline-2,4(1H,3H)-dione, 6-methylquinazoline-2,4(1H,3H)-dione, 7-methylquinazoline-2,4(1H,3H)-dione or 6,7-dimethoxyquinazoline-2,4(1H,3H)-dione.

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