Preparation method of deuterated chloroform

Abstract

The invention provides a preparation method of deuterated chloroform (CCl3D). The method comprises the following steps: under the action of ultraviolet-visible light and a catalyst, mixing deuterated methane and Cl2 in a photochemical reactor, and sequentially carrying out alkali washing, liquid separation, drying and distillation treatment to obtain deuterated chloroform. According to the method, a novel efficient catalyst is adopted and matched with a photochemical reactor, and selective reaction of deuterated methane and chlorine under mild conditions is achieved. According to the method, raw materials for producing deuterated chloroform are easy to obtain, the preparation period is short, continuous production can be achieved, in addition, by-products such as deuterated monochloromethane and deuterated dichloromethane with certain application value are further produced in the method, and the economic benefits of the whole production process are further improved. In practical application, the deuterated chloroform prepared by the invention not only can improve the analysis accuracy, enhance the repeatability and comparability of experiments and protect experimental equipment and samples, but also can meet specific application requirements and improve the product quality.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of deuterated reagents, and in particular to a deuterated chloroform (CCl 3 D) preparation method. Background Art

[0002] Isotope reagents occupy a pivotal position in the vast field of chemical science and technology. They are not only the key to exploring the mysteries of nature, but also an important tool to promote the development of modern industry. In the field of chemical synthesis, isotope reagents provide scientists with an unprecedented perspective by accurately labeling specific sites of target molecules, allowing in-depth and detailed research on the mechanisms of complex chemical reactions. This ability has greatly promoted the design and synthesis of new compounds and accelerated the process of drug discovery and optimization. In the field of analysis, isotope labeling technology has significantly improved detection sensitivity and specificity, providing strong support for research on substance transformation in organisms, analysis of metabolic pathways, and other studies.

[0003] As an important member of isotope reagents, deuterated chloroform has a wide range of application potentials due to its unique chemical properties. As a solvent, deuterated chloroform can reduce the background signal generated by hydrogen atom exchange and improve the resolution and accuracy of spectral analysis techniques such as nuclear magnetic resonance (NMR); as an intermediate, it can cleverly introduce deuterium-labeled methyl groups, providing a convenient way to prepare specific deuterated compounds. These deuterated compounds have shown unique advantages in drug stability research, metabolite tracking, etc.

[0004] However, the current deuterated chloroform (CCl 3 D) is mainly prepared by the decomposition reaction of deuterated chloroacetaldehyde in a heavy aqueous solution of deuterated sodium hydroxide. However, this method is highly dependent on high-purity deuterated raw materials, deuterated sodium hydroxide and deuterated chloroacetaldehyde. Due to the complex and high cost of the raw material preparation process, it not only prolongs the entire production cycle, but also increases the material cost.

[0005] Therefore, it is urgent to develop a more efficient and economical method for preparing deuterated chloroform (CCl 3 D) route to obtain high-quality products while reducing production costs and shortening production cycles. Summary of the invention

[0006] In view of this, the present invention proposes a deuterated chloroform (CCl) with easy-to-obtain raw materials, short process flow, simple operation, continuous production and certain economic value. 3 D) preparation method.

[0007] In a first aspect, the present invention provides a deuterated chloroform (CCl 3D) is a preparation method, the method comprising: under the action of ultraviolet-visible light and a catalyst, deuterated methane and Cl 2 After mixing in a photochemical reactor, the mixture is washed with alkali, separated, dried, and distilled to obtain deuterated chloroform (CCl 3 D).

[0008] By adopting the above technical scheme, the method has easy-to-obtain raw materials, mild reaction conditions, high reaction efficiency, is environmentally friendly, and is easy to operate.

[0009] Furthermore, the wavelength of the ultraviolet-visible light is 200-800 nm.

[0010] Furthermore, the catalyst is selected from anatase TiO doped with Ce, Zn, Ag, Cu and / or Mn ions. 2 .

[0011] By adopting the above technical solution, not only the synthesis efficiency of deuterated chloroform can be improved, but also the cost and environmental pollution can be reduced.

[0012] Further, the deuterated methane and the Cl 2 The molar ratio is (0.6~1.5):1.

[0013] By adopting the above technical solution, under the molar ratio set by the present invention, the reaction occurring in the reactor can be effectively controlled so that the product is more inclined to the desired deuterated chloroform (such as CCl 3 D, deuterated monochloromethane, deuterated dichloromethane, etc.) rather than other by-products.

[0014] Furthermore, the photochemical reactor is a tubular photochemical reactor or a microchannel photochemical reactor; the inner diameter of the photochemical reactor is 0.1 to 6 mm, and the material is quartz or high borosilicate glass.

[0015] Furthermore, the temperature in the photochemical reactor is set at 20-200°C.

[0016] Further, the deuterated methane and the Cl 2 The residence time of the mixed gas in the photochemical reactor is 0.2 to 1.5 seconds.

[0017] By adopting the above technical solution, the selectivity of the product can be optimized to ensure that as much target product as possible is generated within a limited time, thereby improving production efficiency and reducing energy consumption.

[0018] Furthermore, in the alkaline washing process, the washing liquid is selected from NaOH solution, Na 2 CO 3 Solution, K 2 CO 3One of solution or KOH solution.

[0019] Furthermore, in the drying process, the desiccant is selected from soda lime, Al 2 O 3 or CaCl 2 One of them.

[0020] In a second aspect, the present invention provides a deuterated chloroform (CCl 3 D), the deuterated chloroform (CCl 3 D) The purity is not less than 98% and the abundance is not less than 99%.

[0021] By adopting the above technical scheme, the deuterated chloroform (CCl 3 D) In ​​practical applications, it can not only improve the accuracy of analysis, enhance the repeatability and comparability of experiments, protect experimental equipment and samples, but also meet specific application requirements and improve product quality.

[0022] The method for preparing deuterated chloroform provided by the present invention has the following beneficial effects compared with the prior art:

[0023] The present invention prepares deuterated chloroform (CCl 3 D) has easy-to-obtain raw materials, short preparation cycle, and can be produced continuously, thus having high economic value.

[0024] The present invention adopts a new type of high-efficiency catalyst and cooperates with tubular or microchannel photochemical reactor technology to prepare deuterated chloroform, realizing the selective reaction of deuterated methane and chlorine under mild conditions. By accurately controlling the residence time of the reactants, the yield of the target product deuterated chloroform (CCl 3 In addition, in this process, deuterated monochloromethane, deuterated dichloromethane and other products with certain application value are also produced as by-products, further improving the economic benefits of the overall production process.

[0025] The deuterated chloroform (CCl 3 D) In ​​practical applications, it can not only improve the accuracy of analysis, enhance the repeatability and comparability of experiments, protect experimental equipment and samples, but also meet specific application requirements and improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A gas chromatographic detection chart of the deuterated chloroform product prepared in Example 1 provided by the present invention;

[0028] Figure 2 The mass spectrum of the deuterated chloroform product prepared in Example 1 provided by the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention is further described below in conjunction with specific examples, and the protection scope of the present invention is not limited by the following examples. The sources of the materials mainly involved in the examples are shown in Table 1 below, and the remaining materials not shown are conventional commercial products.

[0031] Table 1 Material source description

[0032] Serial number Material / Equipment Name Specifications / Models factory 1 Gas Chromatography Mass Spectrometer GCMS24000SQ T PerkinElmer 2 Karl Fischer Titrator AKF-3N Shanghai Hegong Scientific Instrument Co., Ltd. 3 Chlorine >99.9％ Anhui Zesen Technology Co., Ltd. 4 Deuterated methane >99％ Wuhan Spectral Isotope Technology Co., Ltd.

[0033] The photochemical reactors used in the following examples of the present invention are all prepared by the following steps, specifically including:

[0034] (1) Tubular photochemical reactor

[0035] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles.

[0036] (2) Microchannel Photochemical Reactor

[0037] A heart-shaped microchannel photochemical reactor is used, which is made of quartz or high borosilicate glass, and the inner diameter of the reactor channel is 0.1-6 mm. Anatase TiO doped with Ce, Zn, Ag, Cu and / or Mn ions is 2 Prepare a suspension with water, the mass ratio of the suspension liquid TiO2 to water is 1:2, drop 1mm nitric acid, send it into a ball mill and grind it for 24 hours to obtain a catalyst suspension;

[0038] After the catalyst suspension is coated inside the microchannel, the microchannel is purged with 6 bar high-pressure nitrogen;

[0039] After the purging was completed, the entire reactor was placed in a heating furnace and dried at 120°C for 4 hours and calcined at 250°C for 4 hours.

[0040] Among them, the ion-doped TiO mentioned in the following examples 2 The preparation method of the catalyst, taking doping Ce and Zn ions as an example, comprises the following steps:

[0041] Take 50 ml of tetrabutyl titanate and slowly add 50 ml of anhydrous ethanol, mix and stir evenly to obtain a tetrabutyl titanate ethanol solution;

[0042] Take 0.1g of cerium nitrate and 0.1g of zinc nitrate, add 50ml of distilled water, then add 10ml of concentrated nitric acid and 20ml of anhydrous ethanol, stir until all solids are dissolved, add the obtained solution into the tetrabutyl titanate ethanol solution, continue stirring at room temperature for 5h to obtain a mixed solution;

[0043] The mixed liquid was added into a reactor and heated at 140°C for 6 hours. After cooling, the supernatant was removed. The mixture was dried at 100°C for 2 hours. After crushing, it was put into a high-temperature furnace at 550°C and roasted for 4 hours. The finished product was obtained after screening.

[0044] The following are examples of the present invention.

[0045] Example 1

[0046] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0047] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0048] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0049] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0050] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0051] After analysis, the crude deuterated chloroform contained 78% deuterated chloroform, 19% deuterated dichloromethane and 2% deuterated monochloromethane.

[0052] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 95%.

[0053] Combination Figure 1 , Figure 2 It can be seen that the deuterated chloroform product prepared by this method has high purity, and the mass spectrum characteristics are consistent with those of deuterated chloroform, indicating that this method can prepare high-purity deuterated chloroform.

[0054] Example 2

[0055] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0056] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Cu and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0057] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0058] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0059] The gas at the reactor outlet is passed into a NaOH solution for alkaline washing, and the gas is allowed to stand for stratification. The lower layer of liquid is taken and passed into a drying column filled with soda lime to obtain crude deuterated chloroform after drying.

[0060] After analysis, the crude deuterated chloroform contained 75% deuterated chloroform, 21% deuterated dichloromethane and 3% deuterated monochloromethane.

[0061] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 91%.

[0062] Example 3

[0063] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0064] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase-type TiO2 doped with Mn ions and a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0065] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0066] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0067] The gas at the reactor outlet is passed into a potassium carbonate solution for alkaline washing, and the gas is allowed to stand for stratification. The lower layer of liquid is taken and passed into a drying column filled with alumina to obtain crude deuterated chloroform after drying.

[0068] After analysis, the crude deuterated chloroform contained 70% deuterated chloroform, 25% deuterated dichloromethane and 4% deuterated monochloromethane.

[0069] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 85%.

[0070] Example 4

[0071] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0072] In a quartz tube with an inner diameter of 6 mm and a length of 100 mm, anatase-type TiO2 doped with Ag ions and a particle size of 20 mesh was filled. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0073] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0074] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0075] The gas at the reactor outlet is passed into a KOH solution for alkaline washing, and the layers are allowed to stand for stratification. The lower layer of liquid is taken and passed into a drying column filled with calcium chloride to obtain crude deuterated chloroform after drying.

[0076] After analysis, the crude deuterated chloroform contained 67% deuterated chloroform, 26% deuterated dichloromethane and 4% deuterated monochloromethane.

[0077] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 81%.

[0078] Example 5

[0079] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0080] A microchannel reactor with a characteristic size of 0.1 mm was used, and the interior was coated with anatase TiO doped with Ce and Zn ions. 2 Particles.

[0081] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0082] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0083] The gas at the reactor outlet was passed into a saturated sodium carbonate solution, and after alkali washing, the layers were separated, and the lower layer of liquid was taken and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0084] After analysis, the crude deuterated chloroform contained 82% deuterated chloroform, 14% deuterated dichloromethane and 3% deuterated monochloromethane.

[0085] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 99%.

[0086] Example 6

[0087] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0088] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0089] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 20°C, and the wavelength of UV-visible light is 400nm;

[0090] Deuterated methane and chlorine are mixed in a molar ratio of 1:1, and the mixed gas is introduced into the above reactor, and the gas flow rate is controlled by a mass flow meter to be 90 ml / min, corresponding to a residence time of 1.5 s;

[0091] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0092] After analysis, the crude deuterated chloroform contained 79% deuterated chloroform, 15% deuterated dichloromethane and 2% deuterated monochloromethane.

[0093] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 93%.

[0094] Example 7

[0095] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0096] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0097] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 150°C, and the wavelength of UV-visible light is 400nm;

[0098] Deuterated methane and chlorine are mixed in a molar ratio of 1:1, and the mixed gas is introduced into the above reactor, and the gas flow rate is controlled by a mass flow meter to be 680 ml / min, corresponding to a residence time of 0.2 s;

[0099] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0100] After analysis, the crude deuterated chloroform contained 80% deuterated chloroform, 16% deuterated dichloromethane and 3% deuterated monochloromethane.

[0101] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 68%.

[0102] Example 8

[0103] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0104] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0105] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 20°C, and the wavelength of UV-visible light is 200nm;

[0106] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0107] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0108] After analysis, the crude deuterated chloroform contained 67% deuterated chloroform, 23% deuterated dichloromethane and 7% deuterated monochloromethane.

[0109] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 76%.

[0110] Example 9

[0111] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0112] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0113] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 20°C, and the wavelength of UV-visible light is 800nm;

[0114] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0115] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0116] After analysis, the crude deuterated chloroform contained 65% deuterated chloroform, 24% deuterated dichloromethane and 8% deuterated monochloromethane.

[0117] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 71%.

[0118] Example 10

[0119] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0120] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0121] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 20°C, and the wavelength of UV-visible light is 400nm;

[0122] Deuterated methane and chlorine were mixed at a molar ratio of 0.6:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0123] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0124] After analysis, the crude deuterated chloroform contained 65% deuterated chloroform, 23% deuterated dichloromethane and 10% carbon tetrachloride.

[0125] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 80%.

[0126] Embodiment 11

[0127] This embodiment provides a method for preparing deuterated chloroform, comprising the following steps:

[0128] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0129] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 20°C, and the wavelength of UV-visible light is 400nm;

[0130] Deuterated methane and chlorine were mixed in a molar ratio of 1.5:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0131] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0132] After analysis, the crude deuterated chloroform contained 19% deuterated chloroform, 14% deuterated dichloromethane and 2% deuterated monochloromethane.

[0133] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 98%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 96%.

[0134] The following is a comparative example of the present application.

[0135] Comparative Example 1

[0136] The difference from Example 1 is that the deuterated methane and the chlorine are mixed in a molar ratio of 0.3:1, and the other conditions remain unchanged.

[0137] After analysis, the crude deuterated chloroform contained 58% deuterated chloroform, 2% deuterated dichloromethane and 40% carbon tetrachloride.

[0138] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 99%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 90%.

[0139] Comparative Example 2

[0140] The difference from Example 1 is that the mixed gas is passed through the reactor, the gas flow rate is controlled to be 24 ml / min by a mass flow meter, the corresponding residence time is 4 s, and the other conditions remain unchanged.

[0141] After analysis, the crude deuterated chloroform contained 38% deuterated chloroform, 2% deuterated dichloromethane and 60% carbon tetrachloride.

[0142] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The purity of the deuterated chloroform was tested by using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C, and the purity was 99%. The abundance was 99% by mass spectrometry. After calculation, the chlorine conversion rate of the overall reaction process was 97%.

[0143] Comparative Example 3

[0144] The difference from Example 1 is that the gas at the reactor outlet is not subjected to alkali washing, and the other conditions remain unchanged.

[0145] The crude deuterated chloroform was titrated with NaOH solution to determine the HCl and Cl 2 The content (converted to HCl) is about 8%. The crude deuterated chloroform is distilled and the fraction at 58-64°C is the deuterated chloroform. The product is titrated with NaOH solution to determine the HCl and Cl 2 The content (converted to HCl) is about 2%.

[0146] After the deuterated chloroform product was neutralized with sodium carbonate, the purity of the obtained deuterated chloroform was tested using an Ellite-5 capillary column and an FID detector with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C. The purity was found to be 93%.

[0147] Comparative Example 4

[0148] The difference from Example 1 is that the lower layer of liquid is not dried, and the other conditions remain unchanged.

[0149] The crude deuterated chloroform was distilled, and the fraction at 58-64°C was collected as deuterated chloroform. The distilled liquid was turbid during the distillation process. The purity of the deuterated chloroform was tested using an Ellite-5 capillary column and an FID detector, with the injection port temperature set at 250°C, the column box temperature set at 60°C, and the detector temperature set at 250°C. The purity was 90%. The product was titrated with a NaOH solution to determine the HCl and Cl2 The content (converted to HCl) is about 0.2%. The water content in the sample is measured using a Karl Fischer titrator, and the water content is about 2%.

[0150] Based on the test results of Examples 1 to 11 and Comparative Examples 1 to 4, it can be obtained that:

[0151] (1) Combining Example 1 with Comparative Example 1, it can be seen that: when increasing Cl 2 When the molar ratio of deuterated methane to deuterated chloroform is 2.5, the product contains a large amount of carbon tetrachloride, which greatly reduces the yield of deuterated chloroform. In addition, due to the CD 4 Need to be recycled, the residual chlorine content in the tail gas increases, which will increase the consumption of alkali solution in the alkali washing process, which is not conducive to the subsequent unreacted CD 4 If the Cl 2 Although the molar ratio of deuterated methane to chlorine can reduce the amount of residual chlorine in the tail gas and the amount of carbon tetrachloride in the product, it will greatly increase the CD 4 According to the comparison between Example 1 and Example 10, it can be found that when Cl 2 When the molar ratio of Cl to deuterated methane is above 1.5, the effect of improving the chlorine conversion rate and the purity of deuterated chlorine is not significant. 2 It is appropriate to control the molar ratio of deuterated methane to be between 1:(0.6 and 1.5).

[0152] (2) Combining Example 1 with Comparative Example 2, it can be seen that if the residence time of the material is extended, although the conversion rate of deuterated methane is improved, the product contains a large amount of carbon tetrachloride, which is not a deuterated reagent. The increase of carbon tetrachloride will greatly reduce the yield of deuterated chloroform.

[0153] (3) Combining Example 1 with Comparative Example 3, it can be seen that: since the gas at the outlet of the reactor of Comparative Example 3 (i.e., the reaction product) has not been alkali washed, the product contains acidic gases such as chlorine and hydrogen chloride. The presence of acidic gases will cause the subsequent deuterated methane to be acidic, reducing the purity of the deuterated methane product. This limits its application in the field of analysis. At the same time, since the deuterated methane tail gas contains acidic gases that are easy to corrode equipment, it is not conducive to the subsequent recovery and utilization of deuterated methane.

[0154] (4) Combining Example 1 with Comparative Example 4, it can be seen that: since the lower layer liquid obtained by stratification in Comparative Example 4 was not dried, water and crude deuterated chloroform were distilled out together in the subsequent distillation process, resulting in a turbid distillate. This results in a high water content in the product, which will cause the product to interfere with the analysis results due to water when used as a reagent for nuclear magnetic resonance analysis.

[0155] (5) By comparing Example 1 with Example 5, it can be seen that the reaction yield and the yield of deuterated chloroform can be further improved by using a microchannel reactor.

[0156] (6) By comparing Example 1 with Examples 8 and 9, it can be seen that the photocatalytic wavelength suitable for this reaction is 200-800nm, and the conversion rate of the reaction can reach the optimal value around 400nm.

[0157] (7) By comparing Examples 1-4, it can be seen that using different ion doping on the catalyst can improve the catalyst efficiency, and the effect of multi-component doping is better than that of single-component doping.

[0158] In summary, by controlling reasonable Cl 2 The ratio of deuterated methane to deuterated chloroform is ensured to be in excess, and the crude deuterated chloroform is purified through alkaline washing and absorption processes to ensure the abundance and purity of deuterated chloroform.

[0159] On the basis of the above embodiments, the inventors further optimized the reaction process to obtain Embodiment 12, which specifically comprises the following steps:

[0160] 1) Reaction:

[0161] A quartz tube with an inner diameter of 6 mm and a length of 100 mm was filled with anatase TiO2 doped with Ce and Zn ions and with a particle size of 20 mesh. 2 Particles, as a photoreactor for the preparation of deuterated chloroform;

[0162] The reactor is placed in a UV lamp cavity equipped with a heating system, the temperature in the UV lamp cavity is 200°C, and the wavelength of UV-visible light is 400nm;

[0163] Deuterated methane and chlorine were mixed in a molar ratio of 1:1, and the mixed gas was introduced into the above reactor, and the gas flow rate was controlled to be 170 ml / min by a mass flow meter, corresponding to a residence time of 0.8 s;

[0164] 2) Purification

[0165] The gas at the reactor outlet was passed into a saturated sodium carbonate solution for alkaline washing, and the lower layer of liquid was taken out and passed into a tube filled with CaCl 2 The crude deuterated chloroform was obtained after drying in a drying column.

[0166] 3) Semi-heavy water recovery

[0167] During the purification process, the pH value of the saturated sodium carbonate solution is measured. When it changes to 5-6, the ventilation is stopped, and the sodium carbonate solution that has absorbed DCl is sent to the evaporator for evaporation. The evaporation condensate is collected as semi-heavy water. The semi-heavy water is sent to the heavy water distillation tower to obtain heavy water.

[0168] 4) Deuterated methane recovery

[0169] The tail gas obtained after the reactor gas passes through a saturated sodium carbonate solution is compressed into a steel cylinder by a compressor to recover deuterated methane, which is mixed with chlorine gas in the next batch of reactions and used as raw gas.

[0170] The deuterated methane can be recycled and utilized by recovering the deuterated methane, so that the conversion rate of the deuterated methane reaches more than 95%.

[0171] The recovery of semi-heavy water in the saturated sodium carbonate solution can recover the D element converted into DC1 in the reaction, thus avoiding the emission of D atoms and further improving the economic benefits.

[0172] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing deuterated chloroform, characterized in that: The method comprises: Under the action of ultraviolet-visible light and catalyst, deuterated methane and Cl2 are mixed in a photochemical reactor, and then subjected to alkaline washing, liquid separation, drying and distillation treatment in sequence to obtain deuterated chloroform.

2. The preparation method according to claim 1, characterized in that The wavelength of the ultraviolet-visible light is 200-800nm.

3. The preparation method according to claim 1, characterized in that: The catalyst is selected from anatase TiO2 doped with Ce, Zn, Ag, Cu and / or Mn ions.

4. The preparation method according to claim 1, characterized in that: The molar ratio of the deuterated methane to the Cl2 is (0.6-1.5):

1.

5. The preparation method according to claim 1, characterized in that: The photochemical reactor is a tubular photochemical reactor or a microchannel photochemical reactor; the inner diameter of the photochemical reactor is 0.1-6 mm, and the material is quartz or high borosilicate glass.

6. The preparation method according to claim 1, characterized in that: The temperature in the photochemical reactor is set at 20-200°C.

7. The preparation method according to claim 1, characterized in that: The residence time of the mixed gas of deuterated methane and Cl2 in the photochemical reactor is 0.2 to 1.5 seconds.

8. The preparation method according to claim 1, characterized in that: In the alkaline washing process, the washing liquid is selected from one of NaOH solution, Na2CO3 solution, K2CO3 solution or KOH solution.

9. The preparation method according to claim 1, characterized in that: In the drying process, the desiccant is selected from one of soda lime, Al2O3 or CaCl2.

10. Deuterated chloroform prepared by the preparation method according to any one of claims 1 to 9, characterized in that: The purity of the deuterated chloroform is not less than 98%, and the abundance is not less than 99%.

Images