Structural analysis method for phencyclidine and analogues thereof based on EI mass spectrometry

Abstract

The invention relates to the field of molecular structure mass spectrum analysis, in particular to a phencyclidine and analogue structure analysis method based on EI mass spectrum. The method comprises the following steps: acquiring a characteristic ion sequence of a suspicious object in an EI mass spectrum mode; s30, judging whether the characteristic ion sequence meets the conditions of phencyclidine and analogues thereof or not, and if yes, turning to the step S30; if not, determining that the suspicious object is not phencyclidine and analogues thereof, and ending the analysis; judging the structures of pyrrolidine and piperidine in the suspicious object according to the characteristic ion M6; according to the characteristic ion M5, judging the structures of the thiophene ring and the benzene ring in the suspicious object; if yes, turning to step S40; if not, reducing the structure of the compound, and ending the analysis; the equation (1) and the equation (2) are solved according to the characteristic ion sequence, the results of x and y are obtained, x represents CH2, y represents O, and the structure of R in the suspicious object is judged; and restoring the suspicious object structure, and ending the analysis.

Description

Technical Field

[0001] This invention relates to the field of molecular structure mass spectrometry analysis, and in particular to a method for analyzing the structure of benzyl benzoate and its analogues based on EI mass spectrometry. Background Technology

[0002] Phencyclidine-type substances (PCPs) act as central nervous system stimulants or dissociators, modulating the activity of N-methyl-D-aspartate (NMDA) receptors in the brain, inducing a feeling of detachment and isolation from self and environment. Liu Cuimei et al. studied the mass spectrometry fragmentation patterns of several novel psychoactive substances, including ketamine structural analogs, in electron ionization (EI) and electrospray-collision induced dissociation (ESI-CID) modes and successfully applied them to the structural deduction of real samples. Similarly, Xu Yu et al. applied the EI-MS fragmentation patterns of novel etomidate analogs to the analytical methods for this type of structure using computer language and computational formulas.

[0003] The electronic distribution of ketamine structural analogs differs significantly from that of phencyclidine and its analogs, and their fragmentation pathways and characteristic ions also differ. Phencyclidine and its analogs exhibit a richer variety of fragmentation pathways and higher abundance of molecular ion peaks; besides the aforementioned fragmentation mechanisms, the most prominent is the base peak generated by intracyclic rearrangement fragmentation. Furthermore, etomidate analogs share a common core structure. The current technical approach for mass spectrometry fragmentation analysis of etomidate analogs does not involve the identification of characteristic functional groups in the compound, but rather identifies substituents through characteristic ions during the fragmentation process. In contrast, the different functional groups in the core structure of phencyclidine and its analogs possess different stereoconfigurations, requiring further confirmation through more characteristic ions. The structural changes in etomidate analogs mainly involve phenyl substitution or elongation of the tail alkyl chain, while the structural changes in phencyclidine and its analogs primarily involve alterations to the stereogroups on the entire amino or aromatic groups, demonstrating a fundamental difference in structural substitution variations.

[0004] Novel benzo[a]idine structural analogues are characterized by rapid updates, numerous varieties, and a lack of standards, making existing identification methods inadequate for quickly identifying the structures of novel benzo[a]idine and its analogues. Structural identification methods for benzo[a]idine and its analogues mainly include liquid chromatography-high-resolution mass spectrometry (LC-HMS), infrared spectroscopy, Raman spectroscopy, and nuclear magnetic resonance spectroscopy. However, spectroscopic methods are suitable for detecting compounds with high purity but not for detecting benzo[a]idine and its analogues with low purity. Furthermore, LC-HMS and nuclear magnetic resonance spectrometers are 3-5 times more expensive than conventional GC-MS instruments and require complex pretreatment, instrument setup, and spectral interpretation, limiting their use in general laboratories. To address this technical problem, a structural determination method for benzo[a]idine and its analogues based on EI mass spectrometry is proposed. Summary of the Invention

[0005] To address the technical problems existing in the prior art, this invention provides a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry. This method specifically addresses the dependence on liquid chromatography-high resolution mass spectrometry (LC-HMS) and nuclear magnetic resonance (NMR) spectrometry. It obtains characteristic ions from the EI mass spectra of suspected compounds, analyzes the fragmentation patterns of these characteristic ions, designs a set of targeted equations based on the intrinsic relationships among the ion fragments of such compounds, and infers the compound structure through calculations. This invention is characterized by its wide applicability, high efficiency, and low cost.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: In a first aspect, in one embodiment of the present invention, a method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry is provided, the method comprising the following steps: S10. Obtain the characteristic ion sequence of the suspected substance in EI mass spectrometry mode. The molecular structures of the suspected substance, benzophenone, and its analogues are as follows: or ; S20. Determine whether the characteristic ion sequence meets the conditions for benzylpyridin and its analogues. If yes, proceed to step S30; otherwise, consider the suspect to be neither benzylpyridin nor its analogue, and the analysis ends. S30. Based on characteristic ion M6, determine the structures of pyrrolidine and piperidine in the suspected compound; based on characteristic ion M5, determine the structures of the thiophene ring and benzene ring in the suspected compound; if the compound has a benzene ring structure, proceed to step S40; otherwise, reduce the compound structure and the analysis ends. S40. Solve equations (1) and (2) based on the characteristic ion sequence, and obtain the results of x and y, where x represents CH2 and y represents O to determine the structure of R in the suspect substance; M3 = 158 + 14x + 16y (1) M4 = 117 + 14x + 16y (2); The structure of the suspected object has been reconstructed, and the analysis is now complete.

[0007] As a further aspect of the present invention, step S10 includes: S101. Identify the high mass-to-charge ratio region M in suspicious objects; S102, the characteristic ion sequences generated by the control are M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5 [91 / 97], M6 [70 / 84].

[0008] As a further aspect of the present invention, step S20 includes: S201. Determine whether sequence M conforms to: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5 [91 / 97], M6 [70 / 84]; S202. If sequence M matches, proceed to step S30; if sequence M does not match, the suspect is considered not to benzylpyridin or its analogues, and the analysis ends.

[0009] As a further aspect of the present invention, step S30 includes: If M6=70, then n=0, and the heterocyclic amine in the suspected substance's structure is pyrrolidine; if M6=84, then n=1, and the heterocyclic amine in the suspected substance's structure is piperidine.

[0010] As a further aspect of the present invention, step S30 further includes: If M5=97, the suspected substance contains a thiophene ring in its structure; if M5=91, the suspected substance contains a benzene ring in its structure.

[0011] As a further aspect of the present invention, step S30 further includes: If the compound has a benzene ring structure, proceed to step S40; otherwise, reduce the compound structure and the analysis ends.

[0012] As a further aspect of the present invention, step S40 includes: S401. Solve equations (1) and (2) based on the characteristic ion sequence. M3 = 158 + 14x + 16y (1) M4 = 117 + 14x + 16y (2); S402. If we find that x < 0 and y < 0, then we consider that the suspected substance is not benzylpyridin or its analogues, and the analysis ends. If we find x=0 and y=0, then R is -H; If we find x=0 and y=1, then R is -OH; If we find x=1 and y=0, then R is -CH3; If we find x=1 and y=1, then R is -OCH3; S403. Based on the structure of R, reconstruct the structure of the suspected object. The analysis ends here.

[0013] As a further aspect of the present invention, step S402 includes: If we find x=0 and y=0, then R is -H; If we find x=0 and y=1, then R is -OH.

[0014] As a further aspect of the present invention, step S402 includes: If we find x=1 and y=0, then R is -CH3; If we find x=1 and y=1, then R is -OCH3.

[0015] As a further aspect of the present invention, the characteristic ion sequence of the suspected substance in EI mass spectrometry mode is obtained by gas chromatography-mass spectrometry.

[0016] The technical solution provided by this invention has the following beneficial effects: This invention provides a method for structural analysis of phencyclidine and its analogues based on EI mass spectrometry. Based on the fragmentation rules of mass spectrometry, it designs an original binary equation mathematical model tailored to the structural characteristics and fragmentation rules of phencyclidine and its analogues. By solving the binary equation system, the substituent structure is inferred, directly deducing the molecular structure of suspected substances from the basic functional groups and substituents of the compound. This provides a basis for the rapid identification of phencyclidine and its analogues, solving the identification difficulties caused by the rapid iteration and wide variety of novel phencyclidine structural analogues and the lack of standards. This invention has advantages such as adaptability to more application scenarios, reduced identification costs, and improved work efficiency.

[0017] These or other aspects of the invention will become more apparent from the following description of embodiments. It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry, according to an embodiment of the present invention.

[0020] Figure 2 This invention provides a method for determining the structure of benzylpyridin and its analogues using EI mass spectrometry, which illustrates the generation pathway of characteristic ion fragments of benzylpyridin structural analogues in EI-MS mode.

[0021] Figure 3 This is the mass spectrum of benzylpyridinin in EI-MS mode.

[0022] Figure 4 This is a mass spectrometric fragmentation pathway diagram of benzylpyridinin in EI-MS mode.

[0023] Figure 5 This is the mass spectrum of 3-[1-(piperidin-1-yl)cyclohexyl]phenol in EI-MS mode.

[0024] Figure 6 This is a mass spectrometry diagram of the fragmentation pathway of 3-[1-(piperidin-1-yl)cyclohexyl]phenol in EI-MS mode.

[0025] Figure 7 This is the mass spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0026] Figure 8 This is a mass spectrometric fragmentation pathway diagram of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0027] Figure 9 This is the mass spectrum of 1-[1-(3-methylphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0028] Figure 10 This is a mass spectrometric fragmentation pathway diagram of 1-[1-(3-methylphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0029] Figure 11 This is the mass spectrum of 1-[1-2-(thienyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0030] Figure 12 This is a mass spectrometry fragmentation pathway diagram of 1-[1-2(thienyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0031] Figure 13 The image shows the 1H NMR spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0032] Figure 14 The image shows the 13C NMR spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0033] Figure 15 The image shows the HSQC spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0034] Figure 16 This is the COSY spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0035] Figure 17The image shows the HMBC spectrum of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine in EI-MS mode.

[0036] Figure 18 The chemical structure of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine and key HMBC and COSY related signals are shown in the figure. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0039] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0040] Specifically, the embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0041] Please see Figure 1 , Figure 1 This is a flowchart of a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry, as provided in an embodiment of the present invention. Figure 1 As shown, the method for structural determination of benzyl benzoate and its analogues based on EI mass spectrometry includes steps S10 to S40.

[0042] S10. Obtain the characteristic ion sequences of the suspected substance in EI mass spectrometry mode. The molecular structures of the suspected substance, benzophenone, and its analogues are as follows: or ; In an embodiment of the present invention, step S10 is specifically S101-S102.

[0043] S101. Identify the high mass-to-charge ratio region M in suspicious objects; S102, the characteristic ion sequences generated by the control are M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5 [91 / 97], M6 [70 / 84].

[0044] It should be noted that the characteristic ion sequences of suspected substances in EI mass spectrometry mode can be obtained by gas chromatography-mass spectrometry.

[0045] S20. Determine whether the characteristic ion sequence meets the conditions for benzylpyridin and its analogues. If yes, proceed to step S30; otherwise, consider the suspect to be benzylpyridin and its analogues not to be benzopyridin and end the analysis.

[0046] In an embodiment of the present invention, step S20 specifically comprises S201-S202.

[0047] S201. Determine whether sequence M conforms to: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5 [91 / 97], M6 [70 / 84]; S202. If sequence M matches, proceed to step S30; if sequence M does not match, the suspect is considered not to benzylpyridin or its analogues, and the analysis ends.

[0048] S30. Based on characteristic ion M6, determine the structures of pyrrolidine and piperidine in the suspected compound; based on characteristic ion M5, determine the structures of thiophene ring and benzene ring in the suspected compound; if the compound has a benzene ring structure, proceed to step S40; otherwise, reduce the compound structure and the analysis ends.

[0049] In an embodiment of the present invention, step S30 specifically comprises S301-S303.

[0050] S301. If M6=70, then n=0, and the heterocyclic amine in the suspected substance's structure is pyrrolidine; if M6=84, then n=1, and the heterocyclic amine in the suspected substance's structure is piperidine.

[0051] S302. If M5=97, the suspected substance contains a thiophene ring in its structure; if M5=91, the suspected substance contains a benzene ring in its structure. S303. If the compound has a benzene ring structure, proceed to step S40; otherwise, reduce the compound structure and the analysis ends.

[0052] S40. Solve equations (1) and (2) based on the characteristic ion sequence, and obtain the results of x and y, where x represents CH2 and y represents O to determine the structure of R in the suspect substance; M3 = 158 + 14x + 16y (1) M4=117+14x+16y (2); Reconstruct the structure of the suspicious object and the analysis ends.

[0053] In an embodiment of the present invention, step S40 specifically comprises S401-S403.

[0054] S401. Solve equations (1) and (2) based on the characteristic ion sequence. M3 = 158 + 14x + 16y (1) M4 = 117 + 14x + 16y (2) S402. If we find that x < 0 and y < 0, then we consider that the suspected substance is not benzylpyridin or its analogues, and the analysis ends. If we find x=0 and y=0, then R is -H; If we find x=0 and y=1, then R is -OH; If we find x=1 and y=0, then R is -CH3; If we find x=1 and y=1, then R is -OCH3; S403. Based on the structure of R, reconstruct the structure of the suspected object. The analysis ends here.

[0055] The technical solution of this invention identifies characteristic ions and confirms their different functional group structures, thereby obtaining the basic structure of the compound. After confirming the characteristic functional groups, it generates characteristic ions through different fragmentation mechanisms of benzocyclopyridinium and its analogues, identifies the unique internal logical relationships of benzocyclopyridinium and its analogues, and then designs an original binary equation mathematical model for the structural characteristics and fragmentation rules of benzocyclopyridinium and its analogues. By solving the binary equation system, the substituent structure is inferred, and the structure is confirmed from the basic functional groups of the compound and the substituents on the functional groups. Benzocyclopyridins and etomidates have fundamental differences in fragmentation mechanisms, fragmentation paths, and structural evolution. Therefore, a novel EI mass spectrometry analysis system needs to be developed for benzocyclopyridins and their analogues. This invention can use a gas chromatography-mass spectrometry (GC-MS) instrument with high selectivity and stable ionization characteristics to obtain the characteristic ions of benzocyclopyridinium and its analogues, thereby quickly determining whether a suspect is a benzocyclopyridinium structural analogue. Based on the fragmentation patterns of mass spectrometry, an original binary equation mathematical model was designed to analyze the structural characteristics and fragmentation patterns of phencyclidine and its analogues. By solving the binary equation system, the substituent structures are inferred, allowing direct deduction of the molecular structure of suspected compounds from their basic functional groups and substituents. This provides a basis for the rapid identification of phencyclidine and its analogues, solving the identification challenges caused by the rapid structural iteration, wide variety, and lack of standards for novel phencyclidine analogues. This invention offers advantages such as adaptability to more application scenarios, reduced identification costs, and improved work efficiency.

[0056] Example 1 Example 1 also provides a method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry, so as to... Figure 3 and Figure 4 Taking benzyl benzoate as an example, combined with Figure 1 and Figure 2 The present invention will be described in further detail, including the following steps: S1. Identify the high mass-to-charge ratio region M=243 in the suspicious substance; compare with the generated characteristic ion sequences: M1=200, M2=186, M3=158, M4=117, M5=91, M6=84; S2. If sequence M matches: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5

[91] , M6

[84] , proceed to step S3; otherwise, the suspected substance is considered not to benzyl benzoate or its analogues, and the analysis ends.

[0057] S3, sequence M6=84, then n=1, the heterocyclic amine in the suspected substance structure is piperidine.

[0058] S4, sequence M5=91, then the suspect contains a benzene ring, so proceed to step S5; S5. Solve equations (1) and (2) based on the characteristic ion sequence: M3 = 158 = 158 + 14x + 16y (1) M4 = 117 = 117 + 14x + 16y (2) S6. Solving for x and y, we get x=0 and y=0, so R is -H; S7. Based on the structures of piperidine, benzene ring, and R, the structure of the suspected substance is deduced to be phenylcyclophenamine. The analysis is now complete.

[0059] Example 2 Example 2 also provides a method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry, so as to... Figure 5 and Figure 6 Taking 3-[1-(piperidin-1-yl)cyclohexyl]phenol as an example, combined with Figure 1 and Figure 2 The present invention will be described in further detail, including the following steps: S1. Identify the high mass-to-charge ratio region M=259 in the suspicious substance; compare with the generated characteristic ion sequences M1=216, M2=202, M3=174, M4=133, M5=91, M6=84.

[0060] S2. If sequence M matches: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5

[91] , M6

[84] , proceed to step S3; otherwise, the suspected substance is considered not to benzyl benzoate or its analogues, and the analysis ends.

[0061] S3, sequence M6=84, then n=1, the heterocyclic amine in the suspected substance structure is piperidine.

[0062] If sequence M5=91, then the suspected substance contains a benzene ring in its structure, so proceed to step S5.

[0063] S5. Solve equations (1) and (2) based on the characteristic ion sequence: M3 = 174 = 158 + 14x + 16y (1) M4 = 133 = 117 + 14x + 16y (2) S6. Solving for x and y, we get x=0 and y=1, so R is -OH.

[0064] S7. Based on the structures of piperidine, benzene ring, and R, the structure of the suspected substance is deduced to be 3-[1-(piperidin-1-yl)cyclohexyl]phenol, and the analysis ends.

[0065] Example 3 Example 3 also provides a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry, so as to... Figure 7 and Figure 8 Taking 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine as an example, combined with Figure 1 and Figure 2 The present invention will be described in further detail, including the following steps: S1. Identify the high mass-to-charge ratio region M=259 in the suspicious substance; compare with the generated characteristic ion sequences M1=216, M2=202, M3=188, M4=147, M5=91, M6=70.

[0066] S2. If sequence M matches: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5

[91] , M6

[70] , proceed to step S3. If not, the suspect is considered not to benzyl benzoate or its analogues, and the analysis ends.

[0067] S3, sequence M6=70, then n=0, the heterocyclic amine in the suspected substance structure is pyrrolidine.

[0068] S4, sequence M5=91, then the suspected substance contains a benzene ring in its structure, so proceed to step S5; S5. Solve equations (1) and (2) based on the characteristic ion sequence: M3 = 188 = 158 + 14x + 16y (1) M4 = 147 = 117 + 14x + 16y (2) S6. Solving for x and y, we get x=1 and y=1, so R is -OCH3; S7. Based on the structures of pyrrolidine, benzene ring, and R, the structure of the suspected substance is deduced to be 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine. The analysis is now complete.

[0069] Example 4 Example 4 also provides a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry, so as to... Figure 9 and Figure 10 Taking 1-[1-(3-methylphenyl)cyclohexyl]pyrrolidine as an example, combined with Figure 1 and Figure 2 The present invention will be described in further detail, including the following steps: S1. Identify the high mass-to-charge ratio region M=243 in the suspicious substance; compare with the generated characteristic ion sequences M1=200, M2=186, M3=172, M4=131, M5=91, M6=70.

[0070] S2. If sequence M matches: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-(M6+1)], M4 [M-43-(M6-1)], M5

[91] , M6

[70] , proceed to step S3; otherwise, the suspected substance is considered not to benzyl benzoate or its analogues, and the analysis ends.

[0071] S3, sequence M6=70, then n=0, the heterocyclic amine in the suspected substance structure is pyrrolidine.

[0072] If sequence M5=91, then the suspected substance contains a benzene ring in its structure, so proceed to step S5.

[0073] S5. Solve equations (1) and (2) based on the characteristic ion sequence: M3 = 172 = 158 + 14x + 16y (1) M4 = 131 = 117 + 14x + 16y (2) S6. Solving for x and y, we get x=1 and y=0, so R is -CH3; S7. Based on the structures of pyrrolidine, benzene ring, and R, the structure of the suspected substance is deduced to be 1-[1-(3-methylphenyl)cyclohexyl]pyrrolidine. The analysis is now complete.

[0074] Example 5 Example 5 also provides a method for structural analysis of benzylpyridinium and its analogues based on EI mass spectrometry, so as to... Figure 11 and Figure 12 Taking 1-[1-2-(thienyl)cyclohexyl]pyrrolidine as an example, combined with Figure 1 and Figure 2 The present invention will be described in further detail, including the following steps: S1. Identify the high mass-to-charge ratio region M=235 in the suspicious substance; compare with the generated characteristic ion sequences M1=192, M2=178, M3=165, M4=123, M5=97, M6=70.

[0075] S2, Sequence M conforms to: high mass-to-charge ratio region M and characteristic ions M1 [M-43], M2 [M-57], M3 [M-M6], M4 [M-43-(M6-1)], M5

[97] , M6

[70] , proceed to step S3; S3, sequence M6=70, then n=0, the heterocyclic amine in the suspected substance structure is pyrrolidine.

[0076] If S4 and sequence M5 = 97, then the suspected substance contains a thiophene ring in its structure.

[0077] S5. Based on the structures of pyrrolidine and thiophene ring, the structure of the suspected substance is deduced to be 1-[1-2(thiophene)cyclohexyl]pyrrolidine, and the analysis ends.

[0078] Example 6 Example 6 also provides an example of using the method of the present invention to perform analysis: The instruments and reagents used in the operation were as follows: Bruker nuclear magnetic resonance spectrometer (400MHz), TMS, CDCl3 (chromatographic grade, Merck & Co., Ltd.).

[0079] Sample preparation method: Dissolve 8 mg of sample in CDCl3 and place in a 5 mm NMR tube for testing. TMS is used as the internal standard.

[0080] The instrument conditions were set as follows: 16 scans of 1H NMR, 2 hours each of 13C NMR, HSQC and HMBC, and 1 hour of COSY scan.

[0081] The data analysis results are as follows: Based on the mass spectrometry information of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine, its molecular formula is indicated to be C64-C ... 17 H 25 NO. Analyze its 1H and 13C NMR and HSQC spectra (Table 1 and ). Figures 13-17The data indicates the presence of 6 aromatic carbons, including 2 aromatic quaternary carbons and 4 aromatic methines, 1 sp3-hybridized nitrogen-containing quaternary carbon, and 8 sp3-hybridized methylenes, including 2 nitrogen-containing methylenes and 1 methoxy group. This data is very similar to the NMR data of 1-[1-(3-methoxyphenyl)cyclohexyl]piperidine, the only difference being the absence of one methylene signal. Ultimately, the chemical structure of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine was determined through careful analysis of its HMBC and COSY signals. Figure 18 ).

[0082] Table 1. 1H and 1C NMR data of 1-[1-(3-methoxyphenyl)cyclohexyl]pyrrolidine (CDCl3) It should be understood that, as used herein, the singular form "a" is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the associatedly listed items. The embodiment numbers disclosed above are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0083] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry, characterized in that, The method includes the following steps: S10. Obtain the characteristic ion sequence of the suspected substance in EI mass spectrometry mode. The molecular structures of the suspected substance, benzophenone, and its analogues are as follows: or ; S20. Determine whether the characteristic ion sequence meets the conditions for benzylpyridin and its analogues. If yes, proceed to step S30; otherwise, consider the suspect to be neither benzylpyridin nor its analogue, and the analysis ends. S30. Based on characteristic ion M6, determine the structures of pyrrolidine and piperidine in the suspected compound; based on characteristic ion M5, determine the structures of the thiophene ring and benzene ring in the suspected compound; if a benzene ring structure is present, proceed to step S40; otherwise, reduce the compound structure and the analysis ends. S40. Solve equations (1) and (2) based on the characteristic ion sequence, and obtain the results of x and y, where x represents CH2 and y represents O to determine the structure of R in the suspect substance; M3 = 158 + 14x + 16y (1) M4 = 117 + 14x + 16y (2); The structure of the suspected object has been reconstructed, and the analysis is now complete.

2. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 1, characterized in that, Step S10 includes: S101. Identify the high mass-to-charge ratio region M in suspicious objects; S102, the characteristic ion sequences generated by the control are M1[M-43], M2[M-57], M3[M-(M6+1)], M4[M-43-(M6-1)], M5[91 / 97], and M6[70 / 84].

3. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 2, characterized in that, Step S20 includes: S201. Determine whether sequence M conforms to: high mass-to-charge ratio region M and characteristic ions M1[M-43], M2[M-57], M3[M-(M6+1)], M4[M-43-(M6-1)], M5[91 / 97], M6[70 / 84]; S202. If sequence M matches, proceed to step S30; if sequence M does not match, the suspect is considered not to benzylpyridin or its analogues, and the analysis ends.

4. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 3, characterized in that, Step S30 includes: If M6=70, then n=0, and the heterocyclic amine in the suspected substance's structure is pyrrolidine; if M6=84, then n=1, and the heterocyclic amine in the suspected substance's structure is piperidine.

5. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 4, characterized in that, Step S30 further includes: If M5=97, the suspected substance contains a thiophene ring in its structure; if M5=91, the suspected substance contains a benzene ring in its structure.

6. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 5, characterized in that, Step S30 further includes: If the compound has a benzene ring structure, proceed to step S40; otherwise, reduce the compound structure and the analysis ends.

7. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 6, characterized in that, Step S40 includes: S401. Solve equations (1) and (2) based on the characteristic ion sequence. M3 = 158 + 14x + 16y (1) M4 = 117 + 14x + 16y (2); S402. If we find that x < 0 and y < 0, then we consider that the suspected substance is not benzylpyridin or its analogues, and the analysis ends. S403. Based on the structure of R, reconstruct the structure of the suspected object, and the analysis ends.

8. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 4, characterized in that, Step S402 includes: If we find x=0 and y=0, then R is -H; If we find x=0 and y=1, then R is -OH.

9. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 4, characterized in that, Step S402 further includes: If we find x=1 and y=0, then R is -CH3; If we find x=1 and y=1, then R is -OCH3.

10. The method for structural determination of benzylpyridinium and its analogues based on EI mass spectrometry as described in claim 1, characterized in that, Characteristic ion sequences of the suspected substance in EI mass spectrometry mode were obtained by gas chromatography-mass spectrometry.

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