Method for preparing deuterated hydrochloric acid

Abstract

The invention relates to the technical field of chemical synthesis, in particular to a method for preparing deuterated hydrochloric acid, which comprises the following steps: S1, purifying trichloroacetyl chloride to obtain pure trichloroacetyl chloride; s2, adding pure trichloroacetyl chloride and heavy water in an inert atmosphere, and uniformly mixing; s3, controlling the temperature to be 25-30 DEG C, and generating deuterium hydrochloric acid gas; s4, heavy water is introduced again to form a deuterium chloride heavy water solution; and S5, after the reaction is finished, raising the temperature, controlling the temperature at 85-95 DEG C, and recovering the deuterated hydrochloric acid. According to the heating hydrolysis characteristic of trichlorosilane, heavy water is used for heating hydrolysis to obtain deuterated hydrochloric acid gas, and the deuterated hydrochloric acid gas is introduced into a heavy water solution to obtain a deuterated hydrochloric acid solution; by utilizing the characteristic that trichloroacetyl chloride does not contain hydrogen atoms, hydrogen-deuterium exchange in the reaction process is effectively avoided, so that the deuteration rate is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chemical synthesis, and in particular to a method for preparing deuterated hydrochloric acid. Background Art

[0002] Deuterated hydrochloric acid, as a new deuterated reagent, has some special chemical and physical properties and plays an important role in organic synthetic chemistry and organic chemical mechanism research. In organic synthetic chemistry, it is often used as a deuterated acidic reagent to introduce deuterium atoms into the target organic molecular structure, and is also often used as a deuterated reagent for nuclear magnetic resonance testing. In the existing technology, the yield is low and the by-product organic matter is difficult to remove. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing deuterated hydrochloric acid, so as to solve the technical problems in the prior art that the yield of deuterated hydrochloric acid is low and the by-product organic matter is difficult to remove.

[0005] The invention discloses a method for preparing deuterated hydrochloric acid, comprising the following steps:

[0006] S1. purifying trichloroacetyl chloride to obtain pure trichloroacetyl chloride;

[0007] S2. In an inert atmosphere, add pure trichloroacetyl chloride and heavy water and mix well;

[0008] S3. Control the temperature at 25 to 30°C to generate deuterated hydrochloric acid gas;

[0009] S4. heavy water is introduced again to form a deuterium chloride heavy aqueous solution;

[0010] S5. After the reaction is completed, the temperature is raised and controlled at 85-95°C to recover the deuterated hydrochloric acid.

[0011] The reaction process is as follows:

[0012] C2Cl4O+D2O→C2Cl3O2D+DCl

[0013] Furthermore, in step S5, the filtrate is reheated to generate deuterated hydrochloric acid gas for recycling.

[0014] Furthermore, in step S5, the filtrate is reheated at a temperature of 85-95°C.

[0015] Furthermore, the trichloroacetyl chloride purification is specifically to add trichloroacetyl chloride to anhydrous calcium chloride or molecular sieves, shake well, let stand and then filter to obtain the product.

[0016] Furthermore, the trichloroacetyl chloride is purified to above 99.95%.

[0017] Furthermore, the molecular sieve is 5A molecular sieve.

[0018] Further, the standing time is 3-5 hours.

[0019] Furthermore, in step S2, the mass ratio of trichloroacetyl chloride to heavy water is 8-10:1.

[0020] Furthermore, the deuterated hydrochloric acid gas is injected with heavy water after removing impurities.

[0021] Furthermore, the deuterated hydrochloric acid gas is passed through a cold well to remove impurities.

[0022] Furthermore, a heavy water absorption bottle is arranged in the cold well.

[0023] By setting up a heavy water absorption bottle, a better yield can be obtained.

[0024] Further, when there are no more bubbles in the deuterated heavy water solution in step S4, the addition of heavy water is stopped and the reaction is terminated.

[0025] Furthermore, the inert gas is nitrogen.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Using the characteristics of trichloroacetyl chloride being hydrolyzed by heating, deuterated hydrochloric acid gas can be obtained by heating and hydrolyzing heavy water, and deuterated hydrochloric acid solution can be obtained by passing it into a heavy water solution;

[0028] 2. Taking advantage of the fact that trichloroacetyl chloride does not contain hydrogen atoms, the hydrogen-deuterium exchange during the reaction process is effectively avoided, thereby reducing the deuteration rate;

[0029] 3. The method of the present invention is simple to operate, and deuterium chloride gas can be volatilized safely and stably by adjusting the feeding rate of heavy water;

[0030] 4. By setting up a cold well, an absorption tube containing 20g of heavy water is installed in the cold well to absorb the volatilized trichloroacetyl chloride and recover it;

[0031] 5. The reaction by-product trichloroacetic acid has a high boiling point. By heating, the deuterated hydrochloric acid solution in the reactor is well separated and recovered, thereby improving the yield. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0033] Example 1

[0034] This embodiment discloses a method for preparing deuterated hydrochloric acid, comprising the following steps:

[0035] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0036] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 8:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0037] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 90° C. to recover the deuterated hydrochloric acid.

[0038] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0039] The yield is 91%, the deuteration rate is >99%, and the purity is >99%

[0040] Example 2

[0041] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0042] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0043] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 90° C. to recover the deuterated hydrochloric acid.

[0044] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0045] The yield is 94%, the deuteration rate is >99%, and the purity is >99%

[0046] Example 3

[0047] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0048] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 10:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0049] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 90° C. to recover the deuterated hydrochloric acid.

[0050] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0051] The yield is 92%, the deuteration rate is >99%, and the purity is >99%

[0052] Example 4

[0053] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0054] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0055] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 80° C. to recover the deuterated hydrochloric acid.

[0056] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0057] The yield is 78%, the deuteration rate is >99%, and the purity is >99%

[0058] Example 5

[0059] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0060] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0061] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 100° C. to recover the deuterated hydrochloric acid.

[0062] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0063] The yield is 86%, the deuteration rate is >99%, and the purity is <99%

[0064] Example 6

[0065] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0066] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (including an empty absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0067] Step 3: After the reaction is completed, the temperature is gradually raised and controlled at 90° C. to recover the deuterated hydrochloric acid.

[0068] Step 4: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0069] Yield: 90%, deuteration rate: >99%, purity: >99%

[0070] Example 7

[0071] Step 1: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0072] Step 2: After the reaction is completed, the temperature is gradually raised and controlled at 90° C. to recover the deuterated hydrochloric acid.

[0073] Step 3: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0074] The yield is 92%, the deuteration rate is <98%, and the purity is >99%

[0075] Example 8

[0076] Step 1: Add 5A molecular sieves into a single-mouth round-bottom flask, then add trichloroacetyl chloride, stir, let stand for 4 hours and then filter to obtain pure trichloroacetyl chloride.

[0077] Step 2: nitrogen is introduced into the reaction device, trichloroacetyl chloride and heavy water (mass ratio 9:1) are added to two glass reaction bottles with mechanical stirring, the temperature is controlled at 30°C, stirring is turned on, the generated deuterium chloride gas passes through a cold well (containing a 20g heavy water absorption bottle), the trichloroacetyl chloride mixed with the gas is removed, and the heavy water solution is introduced again to form a deuterated hydrochloric acid solution, and the reaction is stopped when there are no more bubbles in the deuterated heavy water solution.

[0078] Step 3: Determine the mass fraction of deuterium chloride according to the detection method in GB / T 622.

[0079] The yield is 68%, the deuteration rate is >99%, and the purity is >99%

[0080] In Example 1 and Example 3, compared with Example 2, the yield is highest when the feed ratio (mass ratio is 9:1).

[0081] In Example 4 and Example 5, compared with Example 2, the yield and purity are best when the temperature is controlled at 85-95°C.

[0082] Example 6, compared with Example 2, after adding 20g of heavy water into the absorption bottle, the yield is better.

[0083] In Example 7, compared with Example 2, the deuteration rate of the raw materials is the highest after purification.

[0084] In Example 8, compared with Example 2, after the deuterated hydrochloric acid in the reactor was recovered, the yield was significantly improved.

[0085] The above are the implementation methods listed in this embodiment, but this embodiment is not limited to the above optional implementation methods. Those skilled in the art can arbitrarily combine the above methods to obtain other various implementation methods. Anyone can derive other various forms of implementation methods under the inspiration of this embodiment. The above specific implementation methods should not be understood as limiting the scope of protection of this embodiment. The scope of protection of this embodiment shall be based on the definition in the claims, and the description can be used to interpret the claims.

Claims

1. A method for preparing deuterated hydrochloric acid, characterized in that: The following steps are involved: S1. purifying trichloroacetyl chloride to obtain pure trichloroacetyl chloride; S2. In an inert atmosphere, add pure trichloroacetyl chloride and heavy water and mix well; S3. Control the temperature at 25 to 30°C to generate deuterated hydrochloric acid gas; S4. heavy water is introduced again to form a deuterium chloride heavy aqueous solution; S5. After the reaction is completed, the temperature is raised and controlled at 85-95°C to recover the deuterated hydrochloric acid.

2. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: In step S5, the filtrate is reheated to generate deuterated hydrochloric acid gas for recycling.

3. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: The trichloroacetyl chloride purification is specifically performed by adding trichloroacetyl chloride to anhydrous calcium chloride or molecular sieves, shaking well, letting it stand and then filtering to obtain the product.

4. A method for preparing deuterated hydrochloric acid according to claim 3, characterized in that: The molecular sieve is 5A molecular sieve.

5. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: The mass ratio of trichloroacetyl chloride to heavy water in step S2 is 8-10:

1.

6. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: The deuterated hydrochloric acid gas is then fed with heavy water after removing impurities.

7. A method for preparing deuterated hydrochloric acid according to claim 6, characterized in that: The deuterated hydrochloric acid gas passes through a cold well to remove impurities.

8. A method for preparing deuterated hydrochloric acid according to claim 7, characterized in that: A heavy water absorption bottle is arranged in the cold well.

9. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: The reaction is stopped when there are no more bubbles in the deuterated heavy water solution in step S4.

10. A method for preparing deuterated hydrochloric acid according to claim 1, characterized in that: The inert gas is nitrogen.