CN104016889B - A kind of isotope-labeled Sodium Cyclamate and preparation method thereof - Google Patents

Abstract

The invention discloses an isotope-labeled cyclamate and a preparation method thereof. Described cyclamate is isotope deuterium-labeled cyclamate, and its chemical structural formula is: Where: X is H or D. The cyclamate is based on cyclohexanone as a raw material. First, heavy water and cyclohexanone are used for HD exchange to obtain tetradeuterocyclohexanone, and then tetradeuterocyclohexylamine or pentadeuterocyclohexylamine is obtained through reductive amination, and then It is prepared by sulfonation and alkalization. The isotope abundance of the isotope-labeled cyclamate of the invention reaches more than 99%, which fully meets the requirements of detection reagents. Moreover, the method has the advantages of simple synthesis process, cheap raw materials, easy separation and purification of synthesized products, high product purity, low production cost, etc., and has good economy and use value.

Description

A kind of isotope-labeled cyclamate and its preparation method

technical field

The invention relates to an isotope-labeled cyclamate and a preparation method thereof, belonging to the technical field of chemical analysis.

Background technique

Cyclamate is a synthetic sweetener with a chemical name: sodium cyclamate or calcium cyclamate. The sweetness of cyclamate is pure, its sweetness is 40-50 times that of sucrose, and it is a non-nutritive sweetener. Cyclamate can be decomposed into cyclohexylamine which may be chronically toxic under the action of intestinal bacteria. Although it has been used in my country for decades, its safety has been questioned. In the "National Food Safety Standard Food Additive Use Standard" (GB2760-2011) issued by the Ministry of Health of the People's Republic of China, the scope of application and dosage of cyclamate are clearly stipulated. However, driven by profit, cyclamate is often used in excess and beyond the scope, especially in children's food, which is easy to be ingested by children in large quantities for a long time. The immune system of children, especially infants and young children, has not yet matured, and the detoxification ability of the liver is weak. After ingestion, it is easy to cause more serious harm than adults.

At present, the determination of sweeteners in national standards is chromatographic. The import and export industry standard SN/T3538-2013 stipulates the detection methods of six synthetic sweeteners in export foods. Among them, chromatography-mass spectrometry has the advantages of high sensitivity, fast and accurate, and has been more and more widely used in the field of food safety in recent years. more and more attention. However, a major problem that needs to be overcome in the analysis of sweeteners by this method is the matrix effect of complex food samples. Therefore, a relatively tedious and long-term sample processing process is often required. In order to prevent the abuse of cyclamate, food production and processing enterprises and government regulatory departments need a fast and accurate technology to detect it.

Contents of the invention

In view of the above-mentioned problems in the prior art, the object of the present invention is to provide an isotope-labeled cyclamate and a preparation method thereof, so as to realize rapid and accurate detection of cyclamate.

In order to realize the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A kind of isotope-labeled cyclamate, which is isotope deuterium-labeled cyclamate, its chemical structural formula is:

Where: X is H or D.

A method for preparing the isotope-labeled cyclamate of the present invention is to use cyclohexanone as a raw material, first use heavy water (D ₂ O) to exchange HD with cyclohexanone to obtain tetradeuteriocyclohexanone, and then undergo reduction Amination obtains tetradeuterated cyclohexylamine or pentadeuterated cyclohexylamine, and then obtains the described isotope-labeled cyclamate through sulfonation and alkalinization, and its synthetic route is as follows: Where: X is H or D.

As a preferred version, the method of the present invention comprises the following specific steps:

a) adding cyclohexanone to a heavy aqueous solution of sodium deuterium oxide or potassium deuterium oxide, stirring and reacting to obtain a mixed solution of tetradeuterated cyclohexanone and heavy water;

b) adding sodium acetate and hydroxylamine or hydroxylamine hydrochloride to the mixed solution obtained in step a), stirring and reacting at 20-100° C., cooling and crystallizing after the reaction is completed, and filtering to obtain tetradeuterocyclohexanone oxime;

c) Reductive amination reaction of tetradeuterocyclohexanone oxime obtained in step b) with a reducing agent to obtain tetradeuterocyclohexylamine or pentadeuterocyclohexylamine;

d) performing a sulfonation reaction on the tetradeuterocyclohexylamine or pentadeuterocyclohexylamine obtained in step c) with a sulfonating reagent to obtain tetradeuterocyclohexylsulfamic acid or pentadeuterocyclohexylsulfamic acid;

e) Alkalinizing the tetradeuterated cyclamic acid or pentadeuterated cyclamic acid obtained in step d) with sodium hydroxide or calcium hydroxide to obtain the isotope-labeled cyclamate.

The heavy aqueous solution of sodium deuterium oxide described in step a) can be prepared by adding at least one of sodium deuterium oxide, sodium hydroxide, and metal sodium to heavy water; the heavy aqueous solution of potassium deuterium oxide can be obtained by adding It is prepared by adding at least one of potassium deuterium oxide, potassium hydroxide and metal potassium into water; the concentration of the heavy aqueous solution can be 0.001-4.0 mol/L.

The molar ratio of cyclohexanone to heavy water in step a) may be 1:(5-100).

The molar ratio of hydroxylamine or hydroxylamine hydrochloride to tetradeuterated cyclohexanone in step b) may be (1.0-4.0):1.

The molar ratio of the tetradeuterated cyclohexanone oxime to the reducing agent in step c) may be 1:(0.5-5).

When preparing tetradeuterated cyclohexylamine, the reducing agent is preferably lithium aluminum hydride, diisobutylaluminum hydride, borane, sodium borohydride, potassium borohydride, lithium borohydride or hydrogen; In the case of hexylamine, the reducing agent is preferably lithium aluminum deuteride, deuterated borane, sodium borodeuteride, potassium borodeuteride, lithium borodeuteride or deuterium gas.

The sulfonating agent is preferably chlorosulfonic acid, sulfamic acid, sodium sulfamate or sulfur trioxide.

The use of stable isotope internal standard can greatly simplify the sample processing steps in chromatography-mass spectrometry analysis, improve the speed and sensitivity of food sample analysis, and can well offset the error caused by the change of the response signal of the detected substance caused by the matrix, eliminating The error caused by the recovery rate during sample pretreatment. The successful development of stable isotope-labeled cyclamate will greatly simplify the detection process of cyclamate and provide a simple, accurate and reliable analysis and detection technology for food analysis, thus effectively serving food additives in the field of food safety in my country.

The present invention adopts cheap and easy-to-obtain cyclohexanone and heavy water as starting materials, obtains tetradeuterocyclohexanone through deuteration, and then reductively aminates to obtain tetradeuterocyclohexylamine or pentadeuterocyclohexylamine, and then undergoes sulfone Tetradeuterium or pentadeuterium cyclamate can be obtained after basification and basification, and the isotope abundance reaches over 99%, which fully meets the requirements of the detection reagent. The method has the advantages of simple synthesis process, cheap raw materials, easy separation and purification of synthesized products, high product purity (up to 98%), low production cost, etc., and has good economy and use value.

Description of drawings

Fig. 1 is the mass spectrogram of the 2,2,6,6-tetradeuterated sodium cyclamate obtained in Example 4;

Fig. 2 is the ¹ HNMR spectrum of sodium 2,2,6,6-tetradeuteriocyclamate obtained in Example 4.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

Example 1

Add 20mL of heavy water and 100mg of sodium metal into a 50mL eggplant-shaped bottle, add 4mL of cyclohexanone after dissolving, install a reflux condenser, stir and react at 90°C for 3 hours to carry out the H-D exchange reaction, and separate the organic phase after cooling. Obtain the ortho deuterated cyclohexanone; carry out the H-D exchange reaction twice again with the obtained ortho deuterated cyclohexanone, finally obtain the mixed solution of tetradeuterated cyclohexanone and heavy water; Add 6g of hydroxylamine hydrochloride and 9g of sodium acetate to the mixture of heavy water, stir and react at 70°C for 10 minutes, cool down, and precipitate 3.5g of 2,2,6,6-tetradeuteriocyclohexanone oxime, with a molar yield of 76% .

Dissolve 3g of 2,2,6,6-tetradeuterocyclohexanone oxime in 100mL of diethyl ether, add 5g of lithium aluminum hydride, reflux reaction for 30 minutes, add saturated sodium sulfate solution after cooling, so that the unreacted lithium aluminum hydride is just quenched The filter cake was washed with diethyl ether, the filtrate was dried over anhydrous sodium sulfate, and concentrated to obtain 2.2 g of 2,2,6,6-tetradeuteriocyclohexylamine with a molar yield of 81%.

Example 2

Add 20mL of heavy water and 180mg of metal potassium into a 50mL eggplant-shaped bottle, add 4mL of cyclohexanone after dissolving, install a reflux condenser, stir and react at 90°C for 3 hours to carry out the H-D exchange reaction, and separate the organic phase after cooling to obtain Ortho deuterated cyclohexanone. The obtained ortho-deuterated cyclohexanone is subjected to two H-D exchange reactions again, and finally a mixed solution of tetradeuterated cyclohexanone and heavy water is obtained; 6 g of hydrochloric acid is added to the obtained mixed solution of tetradeuterated cyclohexanone and heavy water Hydroxylamine and 9g of sodium acetate were stirred and reacted at 70°C for 10 minutes, cooled, and 3.4g of 2,2,6,6-tetradeuteriocyclohexanone oxime was precipitated with a molar yield of 73%.

Dissolve 3g of 2,2,6,6-tetradeuterocyclohexanone oxime in 100mL of diethyl ether, add 5g of lithium aluminum hydride, reflux reaction for 30 minutes, add saturated sodium sulfate solution after cooling, so that the unreacted lithium aluminum hydride is just quenched The filter cake was washed with diethyl ether, the filtrate was dried over anhydrous sodium sulfate, and concentrated to obtain 2.3 g of 2,2,6,6-tetradeuteriocyclohexylamine with a molar yield of 85%.

Example 3

Dissolve 3g of 2,2,6,6-tetradeuterated cyclohexanone oxime in 80mL of ether, add 3g of lithium aluminum deuteride, reflux for 30 minutes, add saturated sodium sulfate solution after cooling, and make the unreacted lithium aluminum deuteride Just until it was quenched, it was filtered, the filter cake was washed with ether, the filtrate was dried over anhydrous sodium sulfate, and concentrated to obtain 2.3 g of 1,2,2,6,6-pentadeuteriocyclohexylamine with a molar yield of 83%.

Example 4

Add 1g of sulfamic acid, 2g of 2,2,6,6-tetradeuterated cyclohexylamine, and 4mL of o-dichlorobenzene into a 25mL eggplant-shaped bottle, heat the reaction at 200°C for 4 hours, and add 10mL of 10% hydroxide after cooling Sodium solution and 10mL petroleum ether, the organic phase was separated, the water phase was concentrated to about 2mL, cooled and crystallized in ice water, filtered to obtain 1.9g of 2,2,6,6-tetradeuteriocyclamate sodium 1.9g, mol The yield was 92%.

LC-MS detection adopts ESI negative ion mode, the results are shown in Figure 1, the purity>98%; mass spectrometry detection, abundance ≥ 99atom%D; its ¹ HNMR (400MHz, DMSO) detection is shown in Figure 2, δ3.79 (d, J=5.8Hz, 1H), 2.84(d, J=5.6Hz, 1H), 1.59(m, 2H), 1.48(m, 1H), 1.12(m, 3H).

Example 5

Add 1g of sulfamic acid, 2g of 1,2,2,6,6-pentadeuteriocyclohexylamine, and 4mL of o-dichlorobenzene into a 25mL eggplant-shaped bottle, heat the reaction at 200°C for 4 hours, and add 10mL of 10wt% Sodium hydroxide solution and 10mL petroleum ether, the organic phase was separated, the water phase was concentrated to about 2mL, cooled and crystallized in ice water, and filtered to obtain 1,2,2,6,6-pentadeuteriocyclamate sodium 2.0 g, the molar yield is 94%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 6

Add 1g of sulfamic acid, 2g of 2,2,6,6-tetradeuteriocyclohexylamine, 4mL of o-dichlorobenzene into a 25mL eggplant-shaped bottle, heat and react at 200°C for 4 hours, add 1g of calcium hydroxide, 10mL of water and 10mL of petroleum ether, filter off the unreacted calcium hydroxide, separate the organic phase, concentrate the water phase to about 2mL, place it in ice water for cooling and crystallization, and filter to obtain 2,2,6,6-tetradeuterocyclohexyl Calcium sulfamate 1.8g, molar yield is 88%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 7

Add 1g of sulfamic acid, 2g of 1,2,2,6,6-pentadeuteriocyclohexylamine, and 4mL of o-dichlorobenzene into a 25mL eggplant-shaped bottle, heat the reaction at 200°C for 4 hours, add 1g of hydroxide after cooling Calcium, 10mL water and 10mL petroleum ether, unreacted calcium hydroxide was filtered off, the organic phase was separated, the water phase was concentrated to about 2mL, cooled and crystallized in ice water, and filtered to obtain 1,2,2,6,6- Calcium pentadeuterocyclamate 1.9g, the molar yield is 90%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 8

Add 2g of 2,2,6,6-tetradeuteriocyclohexylamine and 10mL of carbon tetrachloride to a 50mL eggplant-shaped bottle, slowly add 0.53mL of chlorosulfonic acid dropwise under ice bath conditions and stir for 2 hours, then cool Then add 10mL of 10wt% sodium hydroxide solution and 10mL of petroleum ether, separate the organic phase, concentrate the water phase to about 2mL, place it in ice water for cooling and crystallization, and filter to obtain 2,2,6,6-tetradeuterated cyclamate Sodium acid 1.8g, the molar yield is 90%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 9

Add 2g of 2,2,6,6-tetradeuteriocyclohexylamine and 10mL of carbon tetrachloride to a 50mL eggplant-shaped bottle, slowly add 0.53mL of chlorosulfonic acid dropwise under ice bath conditions and stir for 2 hours, then cool Then add 1g of calcium hydroxide, 10mL of water and 10mL of petroleum ether, separate the organic phase, concentrate the water phase to about 2mL, place it in ice water for cooling and crystallization, and filter to obtain 2,2,6,6-tetradeuterated cyclamate Calcium acid 1.7g, molar yield is 87%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 10

Add 2g of 1,2,2,6,6-tetradeuteriocyclohexylamine and 10mL of carbon tetrachloride to a 50mL eggplant-shaped bottle, slowly add 0.53mL of chlorosulfonic acid dropwise under ice-bath conditions and stir for 2 hours After cooling, add 10mL of 10wt% sodium hydroxide solution and 10mL of petroleum ether, separate the organic phase, concentrate the water phase to about 2mL, place it in ice water for cooling and crystallization, and filter to obtain 1,2,2,6,6-pentadeuterated Sodium cyclamate 1.8g, the molar yield is 90%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Example 11

Add 2g of 1,2,2,6,6-pentadeuteriocyclohexylamine and 10mL of carbon tetrachloride to a 50mL eggplant-shaped bottle, slowly add 0.53mL of chlorosulfonic acid dropwise under ice bath conditions and stir for 2 hours After cooling, add 1g of calcium hydroxide, 10mL of water and 10mL of petroleum ether, separate the organic phase, concentrate the water phase to about 2mL, place it in ice water for cooling and crystallization, and filter to obtain 1,2,2,6,6-pentadeuterio Calcium cyclamate 1.7g, the molar yield is 87%.

LC-MS detection, purity > 98%; mass spectrometry detection, abundance ≥ 99atom%D.

Finally, it is necessary to explain here that: the above examples are only used to further describe the technical solutions of the present invention in detail, and cannot be interpreted as limiting the protection scope of the present invention. Non-essential improvements and adjustments all belong to the protection scope of the present invention.

Claims (8)

1. an isotope-labeled cyclamate, characterized in that, is the isotope deuterium-labeled cyclamate, and its chemical structural formula is: Where: X is H or D. 2. a method for preparing the described isotope-labeled cyclamate of claim 1 is characterized in that, taking cyclohexanone as raw material, first use heavy water and cyclohexanone to carry out H-D exchange to obtain tetradeuteriocyclohexanone, then through Reductive amination obtains tetradeuterated cyclohexylamine or pentadeuterated cyclohexylamine, and then undergoes sulfonation and alkalization to obtain the described isotope-labeled cyclamate, and its synthetic route is as follows: Where: X is H or D. 3. The method according to claim 2, characterized in that, the method comprises the following specific steps: a) adding cyclohexanone to a heavy aqueous solution of sodium deuterium oxide or potassium deuterium oxide, stirring and reacting to obtain a mixed solution of tetradeuterated cyclohexanone and heavy water; b) adding sodium acetate and hydroxylamine or hydroxylamine hydrochloride to the mixed solution obtained in step a), stirring and reacting at 20-100° C., cooling and crystallizing after the reaction is completed, and filtering to obtain tetradeuterocyclohexanone oxime; c) carrying out reductive amination reaction with the tetradeuterocyclohexanone oxime obtained in step b) and a reducing agent to obtain tetradeuterocyclohexylamine or pentadeuterocyclohexylamine; when preparing tetradeuterocyclohexylamine, the The reducing agent is selected from lithium aluminum hydride, diisobutyl aluminum hydride, borane, sodium borohydride, potassium borohydride, lithium borohydride or hydrogen; when preparing pentadeuterocyclohexylamine, the reducing agent is selected from deuterated aluminum Lithium, deuterated borane, sodium borodeuteride, potassium borodeuteride, lithium borodeuteride, or deuterium gas; d) performing a sulfonation reaction on the tetradeuterocyclohexylamine or pentadeuterocyclohexylamine obtained in step c) with a sulfonating reagent to obtain tetradeuterocyclohexylsulfamic acid or pentadeuterocyclohexylsulfamic acid; e) Alkalinizing the tetradeuterated cyclamic acid or pentadeuterated cyclamic acid obtained in step d) with sodium hydroxide or calcium hydroxide to obtain the isotope-labeled cyclamate. 4. The method according to claim 3, wherein the concentration of the heavy aqueous solution of sodium deuterium oxide or potassium deuterium oxide in step a) is 0.001-4.0 mol/L. 5. The method according to claim 3, characterized in that the molar ratio of cyclohexanone to heavy water in step a) is 1:(5-100). 6. The method according to claim 3, characterized in that: the molar ratio of hydroxylamine or hydroxylamine hydrochloride to tetradeuterocyclohexanone described in step b) is (1.0-4.0):1. 7. The method according to claim 3, characterized in that the molar ratio of the tetradeuterated cyclohexanone oxime to the reducing agent in step c) is 1:(0.5-5). 8. The method according to claim 3, characterized in that: said sulfonating reagent is selected from chlorosulfonic acid, sulfamic acid, sodium sulfamate or sulfur trioxide.