Synthetic compound with picrylamino structure and preparation method thereof
Through the simplified preparation method, the problems of complexity and high cost of traditional processes are solved, and the efficient preparation of high-purity juicylamino compounds is achieved, suitable for industrial production, and has the advantages of environmental protection performance and resource conservation.
Patent Information
- Application Number
- CN202310747675.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-21
- Publication Date
- 2024-12-24
AI Technical Summary
The traditional preparation of juicylamino compounds has complex processes, high cost, large amounts of consumption, high reaction temperature and many by-products, and the post-processing process is cumbersome, which poses safety hazards.
Using a preparation method including synthetic compounds 1, 2 or 3, by gradually adding corresponding reagents under magnetic stirring in an ice water bath, controlling the reaction temperature and time, extracting, washing, drying and filtration, and finally producing a high-purity thyramine group. Structural compounds, simplifying the process flow and reducing the generation of by-products.
The simplification of the synthesis steps, reduced costs, easy access to raw materials, no by-products, and high output, suitable for industrial production, and has good environmental protection performance and resource saving effects.
Smart Images
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of compound preparation, and particularly relates to a synthetic compound with a bitter amino structure and a preparation method thereof. Background Art
[0002] Many compounds with bitter amino structures are used to make high-performance heat-resistant explosives. Heat-resistant explosives generally have a high melting point. Melting point or decomposition temperature is usually used as the basis for judging heat-resistant explosives. They are widely used in nuclear weapons, spacecraft, aerospace rockets and other fields. Most of them use hexanitropine (HNS, Tdec = 318 ° C) and 2,6-bis (bitter amino)-3,5-dinitropyridine (PYX, Tdec = 360 ° C) as their main charge. However, the traditional process for preparing bitter amino compounds is relatively complicated, the cost is high, and the dosage is large; the reaction temperature is high, there are many by-products, it is relatively unsafe, and the post-processing process is relatively cumbersome. Summary of the invention
[0003] Aiming at the defects and problems of the traditional preparation process of bitter amino compounds, such as complex process, high cost, large dosage, high reaction temperature, many by-products, relative unsafety, and cumbersome post-processing process, the present invention provides a synthetic compound with a bitter amino structure and a preparation method thereof.
[0004] The solution adopted by the present invention to solve the technical problem is: a synthetic compound with a bitter amino structure, including synthetic compound 1 or synthetic compound 2 or synthetic compound 3;
[0005] The general structural formula of the synthetic compound 1 is:
[0006]
[0007] The general structural formula of the synthetic compound 2 is:
[0008]
[0009] The general structural formula of the synthetic compound 3 is:
[0010]
[0011] Furthermore, the preparation method of the synthetic compound 1 comprises the following steps:
[0012] 1) Under magnetic stirring in an ice-water bath, 330-350 mL of anhydrous methanol, 64.5-65 g of sodium methoxide and 44.2-44.7 g of 2,6-dichloropyrazine were added to a three-necked reaction flask in sequence, and then the system was heated to reflux overnight to complete the reaction;
[0013] Post-treatment: After the reaction solution was cooled to room temperature, it was slowly poured into 200-300 ml of ice water, extracted, and the organic phases were combined; the combined organic phases were washed with water and saturated sodium chloride aqueous solution respectively, the organic phases were collected, dried over anhydrous sodium sulfate, filtered, and spin-dried to finally generate compound 5;
[0014] 2) Under magnetic stirring in an ice-water bath, 250-300 mL of concentrated sulfuric acid, 60.3-60.8 g of potassium nitrate and 21-21.5 g of compound 5 were added to a three-necked reaction flask in sequence, and then the system was slowly warmed to room temperature and the reaction was continued for 8-10 hours until the reaction was complete;
[0015] The above reaction solution was slowly poured into 400-500 ml of ice water, and a precipitate was precipitated, which was filtered to obtain compound 6;
[0016] 3) 4.5-4.8 g of compound 6 and 25-30 mL of aniline were added to a single-necked flask in sequence under magnetic stirring, and then the system was heated to 100° C. for 10-12 hours to complete the reaction;
[0017] The reaction mixture was cooled to room temperature and filtered to obtain a red solid. The solid was recrystallized from anhydrous methanol to obtain a light yellow solid, which is compound 7.
[0018] 4) 120-150 mL of concentrated sulfuric acid, 30.0-30.3 g of potassium nitrate and 3.50-3.53 g of the above compound 7 were added to a three-necked reaction flask in sequence under magnetic stirring in an ice-water bath, and then the system was slowly heated to room temperature and the reaction was continued for 23-25 hours until the reaction was complete;
[0019] The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally obtain the synthetic compound 1.
[0020] Furthermore, the preparation method of the synthetic compound 2 comprises the following steps:
[0021] 1) Under magnetic stirring in an ice-water bath, 300-320 mL of concentrated sulfuric acid, 60.5-61.0 g of potassium nitrate and 20.8-30.0 g of compound 8 were added to a three-necked reaction flask in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 8-10 hours until the reaction was complete;
[0022] The reaction solution was then slowly poured into 400-500 ml of ice water, and a precipitate was precipitated, which was filtered to obtain compound 9;
[0023] 2) Under magnetic stirring, 100-120 mL of trifluoroacetic acid and 9.10-9.20 g of compound 9 were added to a round-bottom flask in sequence, followed by slowly dropping 25-30 mL of 30% hydrogen peroxide, followed by heating to 100° C. and reacting for 10-12 hours until the reaction was complete;
[0024] The cooled reaction solution was then slowly poured into 400-500 ml of stirred ice water, and a white precipitate was produced. The filtrate was filtered and directly dried to obtain a beige solid, which was the generated compound 10.
[0025] 3) Under magnetic stirring, 2.45-2.50 g of compound 10 and 20-15 mL of aniline were added to the single-necked flask in sequence. After the addition, the system was heated at 100° C. for 9-10 hours to complete the reaction;
[0026] The reaction mixture was cooled to room temperature and filtered to obtain a bright red solid. The solid portion was recrystallized from anhydrous methanol to obtain a light yellow solid, which was compound 11.
[0027] 4) 100-120 mL of concentrated sulfuric acid, 20.0-20.2 g of potassium nitrate and 1.80-1.85 g of compound 11 were added to a three-necked reaction flask in sequence under magnetic stirring in an ice-water bath, and then the system was slowly heated to 40-50° C. and the reaction was continued for 19-20 hours until the reaction was complete;
[0028] The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated, which was filtered to finally generate the synthetic compound 2.
[0029] Furthermore, the preparation method of the synthetic compound 3 comprises the following steps:
[0030] 1) Under magnetic stirring, 80-100 mL of trifluoroacetic acid and 9.0-9.2 g of compound 6 were added to a round-bottom flask in sequence, followed by slowly dropping 25-30 mL of 30% hydrogen peroxide, and then heated to 100° C. for 9-10 hours until the reaction was complete;
[0031] The cooled reaction solution was slowly poured into 450-500 ml of stirred ice water to produce a white precipitate, which was filtered and the filtrate was directly dried to obtain a light yellow solid, which was compound 12;
[0032] 2) Under magnetic stirring, 2.4-2.5 g of compound 12 and 20-25 mL of aniline were added to a single-necked flask in sequence. After the addition, the system was heated at 100° C. for 10-12 hours to complete the reaction;
[0033] The reaction solution was cooled to room temperature and filtered to obtain a bright red solid. The solid portion was recrystallized from anhydrous methanol to obtain a khaki solid, which was compound 13.
[0034] 3) 100-120 mL of concentrated sulfuric acid, 20.0-20.5 g of potassium nitrate and 1.8-1.9 g of compound 13 were added to a 250 mL three-necked reaction bottle in an ice-water bath under magnetic stirring, and then the system was slowly heated to 40-50° C. and the reaction was continued for 19-21 hours until the reaction was complete;
[0035] The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated, which was filtered to finally generate the synthetic compound 3.
[0036] Compared with the prior art, the present invention has the following beneficial effects:
[0037] The three synthetic compounds with bitter amino structures described in the present invention have the advantages of simple synthesis steps, low cost, easy availability of raw materials, no by-products in the preparation process, and high yield, and high-purity products can be obtained without a relatively complicated purification process, and can be industrially produced.
[0038] Through the synthesis steps of the present invention, the products obtained in each step can be effectively recycled, the environmental performance is good, it is beneficial to resource conservation, and the yield of the bitter amino structure finally generated is high. DETAILED DESCRIPTION
[0039] The present invention is further described below in conjunction with embodiments.
[0040] The present invention provides a technical solution for a synthetic compound having a bitter amino structure and a preparation method thereof:
[0041] Embodiment 1:
[0042] This embodiment provides a synthetic compound 1 having a bitter amino structure and a preparation method thereof, wherein the general structural formula of the synthetic compound 1 is:
[0043]
[0044] The preparation process of synthetic compound 1 is:
[0045]
[0046] Specifically, the synthesis of compound 1 includes the following steps:
[0047] 1) Under magnetic stirring in an ice-water bath, 350 mL of anhydrous methanol, (64.8 g / 1.20 mol) of sodium methoxide and (44.7 g / 0.3 mol) of 2,6-dichloropyrazine were added to a 500 mL three-necked reaction bottle in sequence, and then the system was heated under reflux overnight to complete the reaction;
[0048] Post-treatment: After the reaction solution was cooled to room temperature, it was slowly poured into 300 ml of ice water, extracted with 150*3 ml of ether, and the organic phases were combined; the combined organic phases were washed with water and saturated sodium chloride aqueous solution respectively, and the organic phases were collected, dried over anhydrous sodium sulfate, filtered, and spin-dried to finally generate 41.2 g of colorless solid with a yield of 98.1% of compound 5, wherein the general structural formula of compound 5 is
[0049] The above compound 5 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0050] 1 H NMR (600M, CDCl3): 8.01 (s, 2H), 3.87 (s, 6H); Elemental analysis: C 51.24, H 5.82, N 19.76.
[0051] 2) Under magnetic stirring in an ice-water bath, 300 mL of concentrated sulfuric acid, (60.6 g / 0.60 mol) potassium nitrate and the above-produced compound 5 (21.0 g / 0.15 mol) were added to a 500 mL three-necked reaction bottle in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 10 hours until the reaction was complete;
[0052] Post-treatment: The reaction solution was slowly poured into 500 ml of ice water, and a precipitate was precipitated. Compound 6 was obtained by filtration. The generated compound 6 was a light yellow solid, totaling 30.71 g, with a yield of 89.01%.
[0053] The general structural formula of compound 6 is:
[0054] The above compound 6 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0055] 1 H NMR (600M, CDCl3): 4.29 (s, 6H); Elemental analysis: C 31.12, H 2.65, N 24.40.
[0056] 3) Compound 6 (4.60 g / 20 mol) and aniline (30 mL) were added to a 100 mL single-necked flask in sequence under magnetic stirring, and the system was heated to 100° C. for 10 hours until the reaction was complete;
[0057] Post-treatment: The above reaction mixture was cooled to room temperature and filtered to obtain a red solid. The solid portion was recrystallized from anhydrous methanol to obtain a light yellow solid, a total of 6.54 g, with a yield of 92.89% of compound 7; wherein the general structural formula of compound 7 is:
[0058]
[0059] The above compound 7 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0060] 1 H NMR (600M, CDCl3): 10.48 (s, 2H), 9.19-9.43 (m, 10H); Elemental analysis: C 54.44, H 3.49, N 23.77.
[0061] 4) Concentrated sulfuric acid (150 mL), potassium nitrate (30.3 g / 0.30 mol) and compound 7 (3.52 g / 10 mol) were added to a 250 mL three-necked reaction bottle in an ice-water bath under magnetic stirring. The system was then slowly heated to room temperature and the reaction was continued for 24 hours until the reaction was complete.
[0062] The reaction solution was then slowly poured into 300 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally obtain the synthetic compound 1, which was a solid earthy yellow color, totaling 5.47 g, with a yield of 87.94%.
[0063] The synthesized compound 1 was subjected to nuclear magnetic resonance hydrogen spectrum analysis and elemental analysis, and the results were:
[0064] 1 H NMR (600M, CDCl3): 8.86 (s, 2H), 8.78 (s, 4H); Elemental analysis: C 30.75, H 1.05, N 26.99.
[0065] Embodiment 2:
[0066] This embodiment provides a synthetic compound 1 having a bitter amino structure, and its general structural formula is:
[0067]
[0068] The preparation steps of the above-mentioned synthetic compound 1 are:
[0069] 1) Under magnetic stirring in an ice-water bath, 330 mL of anhydrous methanol, 64.5 g of sodium methoxide and 44.5 g of 2,6-dichloropyrazine were added to a 500 mL three-necked reaction bottle in sequence, and then the system was heated to reflux overnight to complete the reaction;
[0070] Post-treatment: After the reaction solution was cooled to room temperature, it was slowly poured into 200 ml of ice water, extracted with 150*3 ml of ether, and the organic phases were combined; the combined organic phases were washed once with water and saturated sodium chloride aqueous solution respectively, the organic phases were collected, dried over anhydrous sodium sulfate, filtered, and spin-dried to finally generate 42.3 g of colorless solid with a yield of 97.2% of compound 5.
[0071] 2) Under magnetic stirring in an ice-water bath, 250 mL of concentrated sulfuric acid, 60.8 g of potassium nitrate and 21.5 g of compound 5 were added to a 500 mL three-necked reaction bottle in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 9 hours until the reaction was complete;
[0072] Post-treatment: The above reaction solution was slowly poured into 500 ml of ice water, and a precipitate was precipitated. Compound 6 was obtained by filtration. The generated compound 6 was a light yellow solid, totaling 31.89 g, with a yield of 90.01%.
[0073] 3) 4.8 g of compound 6 and 25 mL of aniline were added to a 100 mL single-necked flask under magnetic stirring, and the system was heated to 100 °C for 12 hours to complete the reaction;
[0074] Post-treatment: The reaction mixture was cooled to room temperature and then filtered to obtain a red solid. The solid portion was recrystallized from anhydrous methanol to obtain a light yellow solid, which is compound 7. The total amount of compound 7 was 6.3 g, and the yield was 91.26%.
[0075] 4) 120 mL of concentrated sulfuric acid, 30 g of potassium nitrate and 3.5 g of compound 7 were added to a 250 mL three-necked reaction bottle in an ice-water bath under magnetic stirring, and the system was slowly heated to room temperature and the reaction was continued for 25 hours until the reaction was complete;
[0076] The reaction solution was then slowly poured into 200 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally obtain the synthetic compound 1, which was a solid khaki color, totaling 5.38 g, with a yield of 85.98%.
[0077] Embodiment 3:
[0078] This embodiment provides a synthetic compound 2 having a bitter amino structure and a preparation method thereof, wherein the general structural formula of the synthetic compound 2 is:
[0079]
[0080] The preparation process of synthetic compound 2 is:
[0081]
[0082] Specifically, the preparation of synthetic compound 2 includes the following steps:
[0083] 1) In an ice-water bath with magnetic stirring, concentrated sulfuric acid (300 mL), potassium nitrate (60.6 g / 0.60 mol) and 20.85 g / 0.15 mol of the above compound 8 were added to a 500 mL three-necked reaction bottle in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 10 hours until the reaction was complete;
[0084] Post-treatment: The above reaction solution was slowly poured into 500 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to obtain compound 9; compound 9 was a yellow solid, totaling 32.66 g, with a yield of 95.08%, and its general structural formula was:
[0085] The compound 9 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0086] 1 H NMR (600M, CDCl3): 9.15 (s, 1H), 4.10 (s, 6H); Elemental analysis: C 36.56, H 3.11, N 18.55.
[0087] 2) Under magnetic stirring, 100 mL of trifluoroacetic acid and compound 9 (9.16 g / 40 mol) were added to a 250 mL round-bottom flask in sequence, and then 30 mL of hydrogen peroxide (30%) was slowly added dropwise, and then heated to 100 °C for 10 hours to complete the reaction;
[0088] The cooled reaction solution was then slowly poured into 500 ml of stirred ice water, and a white precipitate was produced. The filtrate was filtered and directly dried to obtain a beige solid, namely compound 10; the total amount of compound 10 was 4.90 g, and the yield was 50.0%; its general structural formula was:
[0089]
[0090] The compound 10 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0091] 1 H NMR (600M, CDCl3): 8.95 (s, 1H), 3.95 (s, 6H); Elemental analysis: C 34.21, H 2.67, N 17.32.
[0092] 3) Compound 10 (2.45 g / 10 mol) and aniline (20 mL) were added to a 50 mL single-necked flask in sequence under magnetic stirring. After the addition, the system was heated at 100° C. for 10 hours to complete the reaction.
[0093] The reaction mixture was cooled to room temperature and filtered to obtain a large amount of bright red solid. The solid part was recrystallized with anhydrous methanol to obtain a light yellow solid, which is compound 11. The total amount of compound 11 is 3.42 g, and the yield is 93.19%. The general structural formula is:
[0094]
[0095] The compound 11 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0096] 1 H NMR (600M, CDCl3): 8.88 (s, 1H), 6.89-7.03 (m, 6H), 7.02-7.04 (m, 4H); Elemental analysis: C 55.64, H 3.60, N 19.14.
[0097] 4) Concentrated sulfuric acid (100 mL), potassium nitrate (20.2 g / 0.20 mol) and compound 11 (1.835 g / 5 mol) were added to a 250 mL three-necked reaction bottle in an ice-water bath with magnetic stirring. The system was then slowly heated to 45° C. and the reaction was continued for 20 hours until the reaction was complete.
[0098] The reaction solution was then slowly poured into 200 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally generate the synthetic compound 2. The synthetic compound 2 was a yellow solid, with a total of 1.98 g and a yield of 62.17%. The synthetic compound 2 was subjected to nuclear magnetic hydrogen spectrum analysis and elemental analysis, and the results were:
[0099] 1 H NMR (600M, CDCl3): 8.90 (s, 1H), 8.87 (s, 4H); Elemental analysis: C 32.20, H 3.77, N 19.15.
[0100] Embodiment 4:
[0101] This embodiment provides a synthetic compound 2 having a bitter amino structure, wherein the general structural formula of the synthetic compound 2 is:
[0102]
[0103] The preparation steps of the above-mentioned synthetic compound 2 include:
[0104] 1) Under magnetic stirring in an ice-water bath, 320 mL of concentrated sulfuric acid, 61 g of potassium nitrate and 30 g of the above compound 8 were added to a 500 mL three-necked reaction bottle in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 8 hours until the reaction was complete;
[0105] Post-treatment: the above reaction solution was slowly poured into 500 ml of ice water, and a precipitate was precipitated. It was filtered to obtain compound 9; compound 9 was a yellow solid, a total of 33.21 g, and the yield was 96.21%.
[0106] 2) Under magnetic stirring, 120 mL of trifluoroacetic acid and 9.2 g of compound 9 were added to a 250 mL round-bottom flask in sequence, followed by slow dropwise addition of 25 mL of hydrogen peroxide (30%), followed by heating to 100 °C for 11 hours until the reaction was complete;
[0107] The cooled reaction solution was then slowly poured into 500 ml of stirred ice water, and a white precipitate was produced. The filtrate was filtered and directly dried to obtain a beige solid, namely, compound 10; the total amount of compound 10 was 4.68 g, and the yield was 48.96%.
[0108] 3) Under magnetic stirring, 2.5 g of compound 10 and 15 mL of aniline were added to a 50 mL single-necked flask in sequence. After the addition, the system was heated at 100 °C for 9 hours to complete the reaction;
[0109] Post-treatment: The reaction mixture was cooled to room temperature and then filtered to obtain a large amount of bright red solid. The solid portion was recrystallized with anhydrous methanol to obtain a light yellow solid, which was compound 11. The total amount of compound 11 was 3.29 g, and the yield was 92.86%.
[0110] 4) 120 mL of concentrated sulfuric acid, 20.15 g of potassium nitrate and 1.8 g of compound 11 were added to a 250 mL three-necked reaction bottle in an ice-water bath with magnetic stirring, and the system was then slowly heated to 45°C and the reaction was continued for 19 hours until the reaction was complete;
[0111] The reaction solution was then slowly poured into 300 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally generate the synthetic compound 2. The synthetic compound 2 was a yellow solid, with a total of 1.86 g and a yield of 61.58%.
[0112] Embodiment 5:
[0113] This embodiment provides a synthetic compound 3 having a bitter amino structure and a preparation method thereof, wherein the general structural formula of the synthetic compound 3 is:
[0114]
[0115] The preparation process of synthetic compound 3 is:
[0116]
[0117] Specifically, the preparation of synthetic compound 3 includes the following steps:
[0118] 1) Under magnetic stirring, 100 mL of trifluoroacetic acid and compound 6 (9.20 g / 40 mol) were added to a 250 mL round-bottom flask in sequence, and then 30 mL of hydrogen peroxide (30%) was slowly added dropwise, and then heated to 100 °C for 10 hours to complete the reaction;
[0119] The cooled reaction solution was slowly poured into 500 ml of stirred ice water, and a white precipitate was produced. The filtrate was filtered and directly dried to obtain a light yellow solid, which was compound 12 (3.35 g, yield 34.0%). The general structural formula of compound 12 is:
[0120] The compound 12 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0121] 1 H NMR (600M, CDCl3): 4.18 (s, 6H); Elemental analysis: C 29.30, H 2.57, N 22.35;
[0122] 2) Compound 12 (2.46 g / 10 mol) and aniline (20 mL) were added to a 50 mL single-necked flask in sequence under magnetic stirring. After the addition, the system was heated at 100° C. for 10 hours to complete the reaction.
[0123] The reaction solution was cooled to room temperature and filtered to obtain a large amount of bright red solid. The solid part was recrystallized with anhydrous methanol to obtain a khaki solid, which was compound 13 (3.23 g in total, with a yield of 87.77%). The general structural formula of compound 13 is:
[0124]
[0125] The compound 13 was subjected to H NMR spectrum analysis and elemental analysis, and the results were:
[0126] 1H NMR (600M, CDCl3): 6.71-6.75 (m, 6H), 6.99-7.03 (m, 4H); Elemental analysis: C 52.45, H 3.39, N 22.89.
[0127] 3) Concentrated sulfuric acid (100 mL), potassium nitrate (20.2 g / 0.20 mol) and compound 13 (1.84 g / 5 mol) were added to a 250 mL three-necked reaction bottle in an ice-water bath under magnetic stirring, and then the system was slowly heated to 45°C and the reaction was continued for 20 hours until the reaction was complete;
[0128] The reaction solution was then slowly poured into 200 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally generate the synthetic compound 3, which was a yellow solid, totaling 1.75 g, with a yield of 53.76%. The results of H NMR spectrum analysis and elemental analysis were as follows:
[0129] 1 H NMR (600M, CDCl3): 8.95 (s, 4H); Elemental analysis: C 31.50, H 1.17, N 25.74.
[0130] Embodiment 6:
[0131] This embodiment provides a synthetic compound 3 having a bitter amino structure, wherein the general structural formula of the synthetic compound 3 is:
[0132]
[0133] The preparation of the above-mentioned synthetic compound 3 comprises the following steps:
[0134] 1) Under magnetic stirring, 80 mL of trifluoroacetic acid and 9 g of compound 6 were added to a 250 mL round-bottom flask in sequence, followed by slow dropwise addition of 25 mL of hydrogen peroxide (30%), followed by heating to 100 °C for 9.5 hours until the reaction was complete;
[0135] The cooled reaction solution was slowly poured into 450 ml of stirred ice water to produce a white precipitate, which was filtered and the filtrate was directly dried to obtain a light yellow solid, which was compound 12 (3.29 g, yield 32.85%).
[0136] 2) Under magnetic stirring, 2.5 g of compound 12 and 25 mL of aniline were added to a 50 mL single-necked flask in sequence. After the addition, the system was heated at 100 °C for 12 hours to complete the reaction;
[0137] The reaction solution was cooled to room temperature and then filtered to obtain a large amount of bright red solid. The solid portion was recrystallized with anhydrous methanol to obtain a khaki solid, which was compound 13 (3.46 g in total, with a yield of 89.06%).
[0138] 3) 120 mL of concentrated sulfuric acid, 20.5 g of potassium nitrate and 1.9 g of compound 13 were added to a 250 mL three-necked reaction bottle in an ice-water bath with magnetic stirring, and the system was then slowly heated to 40°C and the reaction was continued for 21 hours until the reaction was complete;
[0139] The reaction solution was then slowly poured into 300 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally generate the synthetic compound 3, which was a yellow solid, with a total of 1.42 g and a yield of 52.68%.
[0140] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A synthetic compound having a bitter amino structure, characterized in that: Including synthetic compound 1 or synthetic compound 2 or synthetic compound 3; The general structural formula of the synthetic compound 1 is: The general structural formula of the synthetic compound 2 is: The general structural formula of the synthetic compound 3 is:
2. The synthetic compound having a bitter amino structure according to claim 1, characterized in that: The preparation method of the synthetic compound 1 comprises the following steps: 1) Under magnetic stirring in an ice-water bath, 330-350 mL of anhydrous methanol, 64.5-65 g of sodium methoxide and 44.2-44.7 g of 2,6-dichloropyrazine were added to a three-necked reaction flask in sequence, and then the system was heated to reflux overnight to complete the reaction; Post-treatment: After the reaction solution was cooled to room temperature, it was slowly poured into 200-300 ml of ice water, extracted with 150*3 ml of ether, and the organic phases were combined; the combined organic phases were washed with water and saturated sodium chloride aqueous solution respectively, and the organic phases were collected, dried over anhydrous sodium sulfate, filtered, and spin-dried to finally generate compound 5; 2) Under magnetic stirring in an ice-water bath, 250-300 mL of concentrated sulfuric acid, 60.3-60.8 g of potassium nitrate and 21-21.5 g of compound 5 were added to a three-necked reaction flask in sequence, and then the system was slowly warmed to room temperature and the reaction was continued for 8-10 hours until the reaction was complete; The above reaction solution was slowly poured into 400-500 ml of ice water, and a precipitate was precipitated, which was filtered to obtain compound 6; 3) 4.5-4.8 g of compound 6 and 25-30 mL of aniline were added to a single-necked flask in sequence under magnetic stirring, and then the system was heated to 100° C. for 10-12 hours to complete the reaction; The reaction mixture was cooled to room temperature and filtered to obtain a red solid. The solid was recrystallized from anhydrous methanol to obtain a light yellow solid, which is compound 7. 4) 120-150 mL of concentrated sulfuric acid, 30.0-30.3 g of potassium nitrate and 3.50-3.53 g of the above compound 7 were added to a three-necked reaction flask in sequence under magnetic stirring in an ice-water bath, and then the system was slowly heated to room temperature and the reaction was continued for 23-25 hours until the reaction was complete; The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated. The precipitate was filtered to finally obtain the synthetic compound 1.
3. The three synthetic compounds having a bitter amino structure according to claim 1, characterized in that: The preparation method of the synthetic compound 2 comprises the following steps: 1) Under magnetic stirring in an ice-water bath, 300-320 mL of concentrated sulfuric acid, 60.5-61.0 g of potassium nitrate and 20.8-30.0 g of compound 8 were added to a three-necked reaction flask in sequence, and then the system was slowly heated to room temperature and the reaction was continued for 8-10 hours until the reaction was complete; The reaction solution was then slowly poured into 400-500 ml of ice water, and a precipitate was precipitated, which was filtered to obtain compound 9; 2) Under magnetic stirring, 100-120 mL of trifluoroacetic acid and 9.10-9.20 g of compound 9 were added to a round-bottom flask in sequence, followed by slowly dropping 25-30 mL of 30% hydrogen peroxide, followed by heating to 100° C. and reacting for 10-12 hours until the reaction was complete; The cooled reaction solution was then slowly poured into 400-500 ml of stirred ice water to produce a white precipitate, which was filtered and the filtrate was directly spin-dried to obtain a beige solid, namely, the generated compound 10; 3) Under magnetic stirring, 2.45-2.50 g of compound 10 and 20-15 mL of aniline were added to the single-necked flask in sequence. After the addition, the system was heated at 100° C. for 9-10 hours to complete the reaction; The reaction mixture was cooled to room temperature and filtered to obtain a bright red solid. The solid portion was recrystallized from anhydrous methanol to obtain a light yellow solid, which was compound 11. 4) 100-120 mL of concentrated sulfuric acid, 20.0-20.2 g of potassium nitrate and 1.80-1.85 g of compound 11 were added to a three-necked reaction flask in sequence under magnetic stirring in an ice-water bath, and then the system was slowly heated to 40-50° C. and the reaction was continued for 19-20 hours until the reaction was complete; The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated, which was filtered to finally generate the synthetic compound 2.
4. The three synthetic compounds having a bitter amino structure according to claim 1, characterized in that: The preparation method of the synthetic compound 3 comprises the following steps: 1) Under magnetic stirring, 80-100 mL of trifluoroacetic acid and 9.0-9.2 g of compound 6 were added to a round-bottom flask in sequence, followed by slowly dropping 25-30 mL of 30% hydrogen peroxide, and then heated to 100° C. for 9-10 hours until the reaction was complete; The cooled reaction solution was slowly poured into 450-500 ml of stirred ice water to produce a white precipitate, which was filtered and the filtrate was directly dried to obtain a light yellow solid, which was compound 12; 2) Under magnetic stirring, 2.4-2.5 g of compound 12 and 20-25 mL of aniline were added to a single-necked flask in sequence. After the addition, the system was heated at 100° C. for 10-12 hours to complete the reaction; The reaction solution was cooled to room temperature and filtered to obtain a bright red solid. The solid portion was recrystallized from anhydrous methanol to obtain a khaki solid, which was compound 13. 3) 100-120 mL of concentrated sulfuric acid, 20.0-20.5 g of potassium nitrate and 1.8-1.9 g of compound 13 were added to a 250 mL three-necked reaction bottle in an ice-water bath under magnetic stirring, and then the system was slowly heated to 40-50° C. and the reaction was continued for 19-21 hours until the reaction was complete; The reaction solution was then slowly poured into 200-300 ml of ice water, and a precipitate was precipitated, which was filtered to finally generate the synthetic compound 3.