A method for preparing 1-bromoadamantane

Abstract

This invention relates to the preparation technology of 1-bromoadamantane, and particularly to a method for preparing 1-bromoadamantane. The technical solution is as follows: adamantane and anhydrous ethanol are added to a reaction vessel, the temperature of the reaction vessel is maintained, and bromine is added dropwise, with the bromine content being 1.2 to 1.4 times the mass of adamantane; after the addition is complete, the temperature is maintained; stirring is started, and the temperature is raised and maintained for reaction multiple times; then the temperature is slowly raised to 85-88°C, and ethanol and unreacted bromine are distilled off. The temperature is then lowered to 40°C, and sodium metabisulfite solution is added dropwise to the reaction vessel. The mixture is then filtered, washed with water until neutral, centrifuged, and dried to obtain 1-bromoadamantane. The beneficial effects of this invention are: the amount of bromine added is small, saving production costs and reducing environmental pollution; the use of ethanol as the reaction solvent and the reflux reaction increase the dispersibility of the reaction between bromine and adamantane, ensuring a complete reaction and reducing the volatility of bromine; the yield of 1-bromoadamantane is 98.1%, and the purity is 99.2%.

Description

Technical Field

[0001] This invention relates to the preparation technology of 1-bromoadamantane, and particularly to a method for preparing 1-bromoadamantane. Background Technology

[0002] 1-Bromoadamantane is an organic chemical, a bromine-substituted derivative of adamantane. It is a white crystalline powder, insoluble in water but soluble in organic solvents, and is an intermediate product in the synthesis of adamantane hydrochloride. Currently, adamantane hydrochloride has wide applications in the pharmaceutical and automotive exhaust fields. The existing synthesis process for 1-bromoadamantane is as follows: adamantane is added to a reaction vessel, and at room temperature and pressure, approximately 2 to 2.4 times the mass of bromine is added. The temperature is raised to about 114°C, and the reaction is carried out in a bromination reaction vessel for 33 to 48 hours. Bromine serves as both a reactant and a solvent. Because bromine is highly volatile, a large amount of bromine is added. After the reaction is complete, the unreacted bromine is distilled at 120°C. Finally, sodium metabisulfite is added dropwise to remove the remaining bromine, and the mixture is filtered and dried to obtain 1-bromoadamantane.

[0003] However, the above preparation process has the following shortcomings:

[0004] 1. The amount of bromine added was too large. The actual mass ratio of bromine to adamantane required for the reaction is 1.18:1. However, due to the volatility of bromine and the need for bromine as a solvent in the reaction, the proportion of bromine added was greatly increased. The actual amount of raw materials added in production resulted in a mass ratio of bromine to adamantane of 2~2.4:1.

[0005] Second, the high temperature and long reaction time in the reaction process resulted in many side reactions in the final product, and the yield and purity of the generated 1-bromoadamantane were low.

[0006] Third, the addition of a large amount of sodium metabisulfite aqueous solution during the bromine removal process leads to the hydrolysis of 1-bromoadamantane in the presence of water for extended periods, producing adamantanol, which reduces the purity of the final product, 1-bromoadamantane. Later in the process of adding sodium metabisulfite, the consumption of bromine as a solvent prevents further dispersion of 1-bromoadamantane, resulting in a large amount of bromine coating the 1-bromoadamantane particles. This prevents complete bromine removal, causing the bromoadamantane to turn reddish and clump, affecting product quality. The addition of large amounts of sodium metabisulfite also increases production costs.

[0007] Fourth, the large amount of bromine-containing wastewater after bromine removal causes serious environmental pollution. Summary of the Invention

[0008] The purpose of this invention is to address the aforementioned deficiencies in the existing technology by providing a method for preparing 1-bromoadamantane, which features a low reaction temperature, fewer byproducts, less bromine usage, less reducing agent usage in the later stages, and lower overall cost.

[0009] The present invention discloses a method for preparing 1-bromoadamantane, the technical solution of which includes the following steps, in weight percentage:

[0010] 1. Add adamantane to the reaction vessel, then add anhydrous ethanol at 5-10% of the total adamantane mass. Keep the temperature of the reaction vessel below 30°C. Add bromine dropwise to the reaction vessel, with the total amount of bromine controlled at 1.2-1.4 times the mass of adamantane. Control the reaction temperature at 30±5°C.

[0011] 2. After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0012] 3. Turn on the stirrer, raise the temperature to 40°C, and keep the reaction at this temperature for 2 hours;

[0013] IV. Heat to 50℃ and maintain the temperature for 2 hours;

[0014] 5. Raise the temperature to 60℃ and maintain the reaction temperature for 2 hours;

[0015] 6. Slowly raise the temperature to 85~88℃ and distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0016] 7. When the temperature drops to 40℃, add a 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0017] 8. Filter, wash with water until neutral, centrifuge, and dry to obtain 1-bromoadamantane.

[0018] The present invention discloses a method for preparing 1-bromoadamantane, the technical solution of which includes the following steps, in weight percentage:

[0019] 1. Add adamantane to the reaction vessel, then add anhydrous ethanol equal to 10% of the total adamantane mass. Keep the temperature of the reaction vessel below 30°C. Add bromine dropwise to the reaction vessel, controlling the total amount of bromine to be 1.3 times the mass of adamantane. Control the reaction temperature at 30±5°C.

[0020] 2. After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0021] 3. Turn on the stirrer, raise the temperature to 40°C, and keep the reaction at this temperature for 2 hours;

[0022] IV. Heat to 50℃ and maintain the temperature for 2 hours;

[0023] 5. Raise the temperature to 60℃ and maintain the reaction temperature for 2 hours;

[0024] 6. Slowly raise the temperature to 85~88℃ and distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0025] 7. When the temperature drops to 40℃, add a 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0026] 8. Filter, wash with water until neutral, centrifuge, and dry to obtain 1-bromoadamantane.

[0027] The beneficial effects of this invention are:

[0028] 1. The amount of bromine added in this invention is small, which saves production costs and reduces environmental pollution;

[0029] 2. In this invention, ethanol is selected as the reaction solvent. The reflux reaction increases the dispersibility of the reaction between bromine and adamantane, making the reaction more complete. The addition of the solvent reduces the volatility of bromine.

[0030] 3. After the reaction is complete, the temperature for distilling and recovering excess bromine is lower than that of the traditional process, requiring only 85~88℃. The recovered ethanol can be recycled for the next reaction.

[0031] 4. During the debromination stage, the presence of ethanol solvent increases the dispersibility of the material, which can completely solve the problems of bromoadamantine agglomerate clumping and incomplete debromination. The bromoadamantine particles are light yellow in color. At the same time, ethanol can carry out a small amount of by-products in the product, increasing the purity of 1-bromoadamantine.

[0032] 5. Due to the small amount of bromine input and thorough recovery, the amount of sodium metabisulfite used is greatly reduced, thus reducing production costs, significantly decreasing the amount of bromine-containing wastewater to be treated, and reducing the generation of byproduct adamantanol.

[0033] 6. After optimizing the reaction conditions, the yield of 1-bromoadamantane can reach 98.1% and the purity can reach 99.2%. Attached Figure Description

[0034] Figure 1 The chromatogram of 1-bromoadamantane prepared in an embodiment of the present invention;

[0035] Figure 2 The chromatogram is of 1-bromoadamantane prepared by the existing process mentioned in the background art. Detailed Implementation

[0036] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0037] Example 1, a method for preparing 1-bromoadamantane mentioned in this invention, includes the following steps, described in weight percentage:

[0038] (1) At room temperature and pressure, add 600 kg of adamantane and 60 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 35℃, and add 720 kg of bromine dropwise.

[0039] (2) After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0040] (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours;

[0041] (4) Heat to 50°C and maintain the temperature for 2 hours;

[0042] (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours;

[0043] (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0044] (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0045] (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 96%, and the purity of 1-bromoadamantane is 96.3%.

[0046] Because the residual amount of bromine is very small, the amount of sodium metabisulfite aqueous solution used in this invention is less than 10% of that in the original process, which greatly reduces the amount of wastewater to be treated. The metabisulfite dripping time is short, and 1-bromoadamantane will not clump when the metabisulfite aqueous solution is added in the presence of a small amount of ethanol, which can achieve a better bromine removal effect. More importantly, under the protection of ethanol, the probability of adamantanol by-product is greatly reduced.

[0047] Example 2, a method for preparing 1-bromoadamantane mentioned in this invention, includes the following steps, described in weight percentage:

[0048] (1) At room temperature and pressure, add 600 kg of adamantane and 60 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 35℃, and add 750 kg of bromine dropwise.

[0049] (2) After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0050] (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours;

[0051] (4) Heat to 50°C and maintain the temperature for 2 hours;

[0052] (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours;

[0053] (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0054] (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0055] (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 96.7%, and the purity of 1-bromoadamantane is 97.8%.

[0056] Example 3, a method for preparing 1-bromoadamantane mentioned in this invention, includes the following steps, which are described in mass percentage below:

[0057] (1) At room temperature and pressure, add 600 kg of adamantane and 60 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 35℃, and add 780 kg of bromine dropwise.

[0058] (2) After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0059] (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours;

[0060] (4) Heat to 50°C and maintain the temperature for 2 hours;

[0061] (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours;

[0062] (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0063] (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0064] (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 98.1%, and the purity of 1-bromoadamantane is 99.2%.

[0065] Example 4, a method for preparing 1-bromoadamantane mentioned in this invention, includes the following steps, described in mass percentage:

[0066] (1) At room temperature and pressure, add 600 kg of adamantane and 50 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 25℃-35℃, and add 840 kg of bromine dropwise.

[0067] (2) After the addition is complete, keep the temperature at 25℃-35℃ for 6 hours to react;

[0068] (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours;

[0069] (4) Heat to 50°C and maintain the temperature for 2 hours;

[0070] (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours;

[0071] (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0072] (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0073] (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 97.8%, and the purity of 1-bromoadamantane is 98.6%.

[0074] Example 5, a method for preparing 1-bromoadamantane mentioned in this invention, includes the following steps, which are described in percentage by mass:

[0075] (1) At room temperature and pressure, add 600 kg of adamantane and 30 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 35℃, and add 780 kg of bromine dropwise.

[0076] (2) After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react;

[0077] (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours;

[0078] (4) Heat to 50°C and maintain the temperature for 2 hours;

[0079] (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours;

[0080] (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distilling when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution can be reused for the next bromination reaction.

[0081] (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine;

[0082] (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 94.6%, and the purity of 1-bromoadamantane is 96.1%.

[0083]

[0084] The preparation process of this invention significantly reduces the amount of wastewater treated because the residual amount of bromine is very small and the amount of sodium metabisulfite aqueous solution used is less than 10% of that in the original process. The metabisulfite addition time is short, and 1-bromoadamantane will not clump when the metabisulfite aqueous solution is added in the presence of a small amount of ethanol, thus achieving a better bromine removal effect. More importantly, under the protection of ethanol, the probability of adamantanol byproduct is greatly reduced.

[0085] Additionally, refer to Figure 1 The image shows the chromatogram of 1-bromoadamantane prepared in Example 3 of this invention. The chromatographic conditions were as follows: (SE-54 cross-linked column, 30 m length, 0.32 mm inner diameter, 0.5 μm film thickness; initial temperature: 100 °C, holding time: 3 min; first-order heating rate: 6 °C / min, first-order final temperature: 140 °C, holding time: 0 min; second-order heating rate: 30 °C / min, second-order final temperature: 240 °C, holding time: 20 min; workstation lockout time: 1.5 min; vaporization chamber temperature: 260 °C; detection chamber temperature: 280 °C).

[0086]

[0087] In the table above, numbers 1-8 represent the components in the 1-bromoadamantane sample ordered by retention time in the chromatogram. Comparison with the standard 1-bromoadamantane sample shows that retention time 5.682 is the retention time of the target product, 1-bromoadamantane. From the concentration sequence in the chart, it can be seen that the optimal method of this invention yields 99.2139% 1-bromoadamantane with a peak area of ​​1051234. Furthermore, the other data appearing in the concentration sequence in the table represent the content of byproducts. Compared with existing processes, this embodiment achieves a 1-bromoadamantane yield of 98.1% and a purity of 99.2139%.

[0088] See attached document Figure 2The chromatogram for 1-bromoadamantane prepared by the existing process mentioned in the background section is shown below. Chromatographic conditions: SE-54 cross-linked column, 30 m length, 0.32 mm inner diameter, 0.5 μm film thickness. Initial temperature: 100 °C, holding time: 3 min; first-order heating rate: 6 °C / min, first-order final temperature: 140 °C, holding time: 0 min; second-order heating rate: 30 °C / min, second-order final temperature: 240 °C, holding time: 20 min. Workstation lockout time: 1.5 min. Vaporization chamber temperature: 260 °C. Detection chamber temperature: 280 °C.

[0089]

[0090] The numbers 1-9 above represent the order of the components in the chromatogram of the 1-bromoadamantane sample according to their retention times. Comparison with the standard 1-bromoadamantane sample shows that retention time 5.686 is the retention time of the target product, 1-bromoadamantane. From the concentration sequence in the table, it can be seen that the existing process can yield 95.5625% 1-bromoadamantane with a peak area of ​​293189. Additionally, the other data appearing in the concentration sequence in the table represent the content of byproducts.

[0091] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the described technical solutions or convert them into equivalent solutions. Therefore, any simple modifications or equivalent substitutions made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing 1-bromoadamantane, characterized in that: Including the following Steps, listed below by weight percentage: (1) At room temperature and pressure, add 600 kg of adamantane and 60 kg of ethanol to the reactor, add bromine dropwise to the reactor, control the dropping rate, observe that the reaction temperature does not exceed 35℃, and add 720 kg of bromine dropwise. (2) After the addition is complete, keep the temperature at 30±5℃ for 6 hours to react; (3) Turn on the stirrer, raise the temperature to 40°C, and keep the temperature for 2 hours; (4) Heat to 50°C and maintain the temperature for 2 hours; (5) Raise the temperature to 60℃ and maintain the temperature for 2 hours; (6) Slowly raise the temperature to 85~88℃, distill off the ethanol and unreacted bromine. Stop distillation when the color of bromine is no longer visible in the reflux tube. The distilled ethanol and bromine solution are recovered for the next bromination reaction. (7) When the temperature drops to 40°C, add 15% sodium metabisulfite solution dropwise to the reaction vessel to remove the remaining bromine; (8) Filter, wash with water until neutral, centrifuge, dry to obtain 1-bromoadamantane. The yield of this reaction process is 96%, and the purity of 1-bromoadamantane is 96.3%.

Images