A method for preparing 2-iminothiazolidin-4-one compounds

Abstract

This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing 2-iminothiazolidine-4-one compounds. The method comprises the following steps: mixing a phenyl isothiocyanate compound, an amine compound, an aryl diazonium ester compound, and a polar organic solvent, and performing a coupling addition reaction to obtain the 2-iminothiazolidine-4-one compound. The preparation method of this invention has advantages such as mild conditions, easy control, high reaction efficiency, economical steps, readily available and inexpensive raw materials, no use of oxidants, and good functional group tolerance. Furthermore, the prepared 2-iminothiazolidine-4-one compounds have high purity (98.5-99.9%), and possess significant market potential.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a method for preparing 2-iminothiazolidin-4-one compounds. Background Technology

[0002] Thiazolidinedion derivatives are an important class of compounds with wide applications, and thiazolidinones are among the most important scaffolds in pharmaceuticals. Furthermore, many thiazolidinone scaffold drugs contain thiazolidinone derivatives and possess a wide range of biological activities. Examples include effective agents for treating Chagas disease and selective glycogen synthase-3β (GSK-3β) inhibitors. Due to their excellent biological activity and synthetic applications, the construction of thiazolidinone scaffolds has attracted considerable attention in recent years.

[0003] Currently, the main methods for synthesizing thiazolidinone derivatives are:

[0004] (a) Wei Guo et al. (Wei Guo, Kailiang Tao, Lvyin Zheng, Mingming Zhao, Wen Tan, Liuhuan Cai, Zhen Xie, Deliang Chen, Xiaolin Fan. Visible-Light-Promoted Three-Component Coupling Annulation: Synthesis of 2-Iminothiazolidin-4-ones via in Situ Formed Electron Donor-Acceptor Complexes[J]. The Journal of Organic Chemistry, 2019, 84(10):6448-6458. DOI:10.1021 / acs.joc.9b00305) reported the generation of 2-iminothiazolidin-4-ones from isothiocyanates, amines, and diethyl butynedioic acid under visible light catalysis, for example:

[0005]

[0006] (b) Wei Guo et al. (Wei Guo, Mingming Zhao, Wen Tan, Lvyin Zheng, Kailiang Tao, Lingxiu Liu, Xinyu Wang, Deliang Chen, Xiaolin Fan, Visible Light-Promoted Three-Component Tandem Annulation for the Synthesis of 2-Iminothiazolidin-4-ones[J]. The Journal of Organic Chemistry, 2018, 83(3):1402-1413. DOI:10.1021 / acs.joc.7b02940.) reported the synthesis of 2-iminothiazolidin-4-ones from isothiocyanates, amines, and ethyl bromoacetate under visible light catalysis, for example:

[0007]

[0008] (c) Mingming Zhao et al. (Mingming Zhao, Yiming Guo, Qi Wang, Lanqi Liu, Shujie Zhang, Wei Guo, Lin-Ping Wu, Fayang G.Qiu. Synthesis of 2-iminothiazolidin-4-ones via copper-catalyzed [2+1+2]tandem annulation[J]. RSC advances, 2023, 13(4):2220-2224. DOI:10.1039 / D2RA07872D.) reported the synthesis of 2-iminothiazolidin-4-ones from isothiocyanates, amines, and ethyl diazonium iodide under the catalysis of cuprous iodide, for example:

[0009] Summary of the Invention

[0010] The purpose of this invention is to provide a method for preparing 2-iminothiazoline-4-one compounds. The method provided by this invention has the advantages of simple process, mild conditions, no use of oxidants and good functional group tolerance.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] This invention provides a method for preparing 2-iminothiazolidin-4-one compounds, comprising the following steps:

[0013] A phenyl isothiocyanate compound, an amine compound, an aryl diazo ester compound, and a polar organic solvent are mixed and subjected to a coupling addition reaction to obtain the 2-iminothiazoline-4-one compound.

[0014] The phenyl isothiocyanate compound has the structure shown in Formula I:

[0015]

[0016] R1 is an aryl group;

[0017] The amine compound has the structure shown in Formula II:

[0018]

[0019] R2 is an aryl group;

[0020] The aryl diazonium ester compounds have the structure shown in Formula III:

[0021]

[0022] R3 is an aryl group;

[0023] The 2-iminothiazolidin-4-one compounds have the structure shown in Formula IV:

[0024]

[0025] Preferably, the phenyl isothiocyanate compounds include one or more of the following: phenyl isothiocyanate, 3-chlorophenyl thioisocyanate, 4-chlorophenyl isothiocyanate, 2-bromophenyl isothiocyanate, 3-bromophenyl isothiocyanate, 4-bromophenyl isothiocyanate, 4-methoxyphenyl isothiocyanate, 3-methoxyphenyl isothiocyanate, phenyl 2,4-dichloroisothiocyanate, phenyl 3,4-dichloroisothiocyanate, and 4-fluorophenyl isothiocyanate.

[0026] Preferably, the amine compound includes one or more of benzylamine, m-chlorobenzylamine, p-chlorobenzylamine, o-bromobenzylamine, m-bromobenzylamine, p-bromobenzylamine, 3-methylbenzylamine, 4-methylbenzylamine, 3-methoxybenzylamine, 3,4-dichlorobenzylamine, 2-thiophenemethylamine, and 3-fluorobenzylamine.

[0027] Preferably, the aryl diazonium ester compounds include one or more of methyl 2-diazo-2-phenylacetate, methyl 2-(4-methoxyphenyl)-2-diazoacetate, methyl 2-(4-bromophenyl)-2-diazoacetate, methyl 2-(4-chlorophenyl)-2-diazoacetate, and methyl 2-(3-bromophenyl)-2-diazoacetate.

[0028] Preferably, the polar organic solvent includes acetonitrile, dichloromethane, or ethyl acetate.

[0029] Preferably, the molar ratio of the phenyl isothiocyanate compound, the amine compound, and the aryl diazo ester compound is 2:2:1.

[0030] Preferably, the ratio of the polar organic solvent to the phenyl isothiocyanate compound is 1L:0.1-0.2mol.

[0031] Preferably, the coupling addition reaction is carried out at room temperature for 1.5 to 3 hours.

[0032] Preferably, the coupling addition reaction is carried out under illumination; the illumination is 10W white LEDs.

[0033] This invention provides a method for preparing 2-iminothiazolidine-4-one compounds, comprising the following steps: mixing a phenyl isothiocyanate compound, an amine compound, an aryl diazonium ester compound, and a polar organic solvent, and performing a coupling addition reaction to obtain the 2-iminothiazolidine-4-one compound. The preparation method of this invention has advantages such as mild conditions, easy control, high reaction efficiency, economical steps, readily available and inexpensive raw materials, no use of oxidants, and good functional group tolerance. Furthermore, the prepared 2-iminothiazolidine-4-one compounds have high purity (98.5–99.9%), and possess significant market potential. Compared with multi-step synthetic reactions, this invention achieves the target product in a single step with a yield of 84%, demonstrating high reaction efficiency and economical steps. Detailed Implementation

[0034] This invention provides a method for preparing 2-iminothiazolidin-4-one compounds, comprising the following steps:

[0035] A phenyl isothiocyanate compound, an amine compound, an aryl diazo ester compound, and a polar organic solvent are mixed and subjected to a coupling addition reaction to obtain the 2-iminothiazoline-4-one compound.

[0036] The phenyl isothiocyanate compound has the structure shown in Formula I:

[0037]

[0038] R1 is an aryl group;

[0039] The amine compound has the structure shown in Formula II:

[0040]

[0041] R2 is an aryl group;

[0042] The aryl diazonium ester compounds have the structure shown in Formula III:

[0043]

[0044] R3 is an aryl group;

[0045] The 2-iminothiazolidin-4-one compounds have the structure shown in Formula IV:

[0046]

[0047] In this invention, R1 in Formula IV is the same as R1 in Formula I; R2 in Formula IV is the same as R2 in Formula II; and R3 in Formula IV is the same as R3 in Formula III.

[0048] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0049] In this invention, R1 in Formulas I and IV preferably includes phenyl, halophenyl, or alkoxyphenyl; the halophenyl preferably includes chlorophenyl, bromophenyl, or fluorophenyl; and the alkoxyphenyl preferably includes methoxyphenyl. In specific embodiments of this invention, the phenyl isothiocyanate compounds preferably include one or more of phenyl isothiocyanate, 3-chlorophenyl thioisocyanate, 4-chlorophenyl isothiocyanate, 2-bromophenyl isothiocyanate, 3-bromophenyl isothiocyanate, 4-bromophenyl isothiocyanate, 3-methoxyphenyl isothiocyanate, 4-methoxyphenyl isothiocyanate, phenyl 2,4-dichloroisothiocyanate, phenyl 3,4-dichloroisothiocyanate, and 4-fluorophenyl isothiocyanate.

[0050] In this invention, R2 in Formulas II and IV preferably includes phenyl, halophenyl, alkylphenyl, alkoxyphenyl, or thienyl; the halophenyl preferably includes chlorophenyl, bromophenyl, or fluorophenyl; the alkylphenyl preferably includes tolyl; and the alkoxyphenyl preferably includes methoxyphenyl. In specific embodiments of this invention, the amine compound preferably includes one or more of benzylamine, m-chlorobenzylamine, p-chlorobenzylamine, o-bromobenzylamine, m-bromobenzylamine, p-bromobenzylamine, 3-methylbenzylamine, 4-methylbenzylamine, 3-methoxybenzylamine, 3,4-dichlorobenzylamine, 2-thienylmethylamine, and 3-fluorobenzylamine.

[0051] In this invention, R3 in Formulas III and IV preferably includes phenyl, halophenyl, or alkoxyphenyl; the halophenyl preferably includes chlorophenyl, bromophenyl, or fluorophenyl; and the alkoxyphenyl preferably includes methoxyphenyl. In specific embodiments of this invention, the aryl diazonium esters preferably include one or more of methyl 2-diazo-2-phenylacetate, methyl 2-(4-methoxyphenyl)-2-diazoacetate, methyl 2-(4-bromophenyl)-2-diazoacetate, methyl 2-(4-chlorophenyl)-2-diazoacetate, and methyl 2-(3-bromophenyl)-2-diazoacetate. In a specific embodiment of the present invention, the aryl diazonium ester compound was prepared with reference to the content in “Davies, Huw ML, Tore Hansen, Melvyn Rowen Churchill. Catalytic asymmetric CH activation of alkanes and tetrahydrofuran[J]. Journal of the American Chemical Society, 2000, 122(13):3063-3070.DOI:10.1021 / ja994136c.”

[0052] In this invention, the polar organic solvent preferably includes acetonitrile, dichloromethane, or ethyl acetate.

[0053] In this invention, the molar ratio of the phenyl isothiocyanate compound, the amine compound, and the aryl diazonium ester compound is preferably 2:2:1. In this invention, the preferred molar ratio of the polar organic solvent to the phenyl isothiocyanate compound is 1 L: 0.1–0.2 mol.

[0054] In this invention, it is preferred to first stir the phenyl isothiocyanate compound, the amine compound, and the polar organic solvent for two hours, and then add the aryl diazonium ester compound.

[0055] In this invention, the coupling addition reaction is preferably carried out at room temperature, and the reaction time is preferably 1.5–3 hours, more preferably 1.5–2 hours. The coupling addition reaction is preferably carried out under illumination, preferably with 10W white LEDs. In this invention, the coupling addition reaction is preferably carried out under stirring conditions. This invention does not impose a specific limit on the stirring rate; any process well-known in the art is sufficient to ensure the reaction proceeds smoothly.

[0056] In this invention, after the coupling addition reaction, the invention preferably further includes purifying the resulting product system. In this invention, the purification method is preferably column chromatography, and the eluent used for column chromatography is preferably a mixed solvent of petroleum ether and ethyl acetate; the volume ratio of petroleum ether to ethyl acetate in the mixed solvent is preferably 1–20:1, more preferably 10–15:1. This invention does not impose any special limitations on the specific process of the column chromatography; any method well known to those skilled in the art can be used. This invention utilizes petroleum ether and ethyl acetate as eluents for purification, which can obtain the target compound with high purity.

[0057] In this invention, the 2-iminothiazolidin-4-one compounds preferably include:

[0058]

[0059]

[0060]

[0061] In this invention, the purity of the 2-iminothiazolidin-4-one compound is preferably 98.5-99.9%; the yield is preferably 46-84%, more preferably 81-84%.

[0062] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0063] Example 1

[0064] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0065]

[0066] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 84% and a purity of 99.9%.

[0067] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0068] 1 H NMR (400MHz, CDCl3, ppm) δ7.53-7.50(m,2H),7.34-7.26(m,10H),7.13-7.08(m,1H),7.01-6.98(m,2H),5.12-4.99(m,3H).

[0069] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.92,152.74,147.98,136.16,135.61,129.33,1 29.17,129.11,128.86,128.61,128.30,128.01,124.80,121.19,51.76,46.66;

[0070] MS(EI,70eV)m / z 358,270,207,121,91,77.

[0071] Example 2

[0072] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0073]

[0074] 0.2 mmol of 3-chlorophenyl thioisocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube and stirred for two hours. Then, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added, and the reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 61% and a purity of 99.9%.

[0075] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0076] 1 H NMR (400MHz, CDCl3, ppm) δ7.49-7.45(m,2H),7.32-7.17(m,9H),7.07-6.99(m,2H),6.86(dd,J=7.8,2.4Hz,1H),5.08-4.95(m,3H).

[0077] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.83,153.91,149.25,136.01,135.37,134.83,130.41,1 29.24,129.06,128.98,128.70,128.33,128.13,124.82,121.61,119.54,51.88,46.72;

[0078] MS(EI,70eV)m / z 392,304,121,91,77.

[0079] Example 3

[0080] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0081]

[0082] 0.2 mmol of 4-chlorophenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 69% and a purity of 99.9%.

[0083] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0084] 1 H NMR (400MHz, CDCl3, ppm) δ7.49-7.46(m,2H),7.31-7.23(m,10H),6.93-6.89(m,2H),5.08-4.95(m,3H).

[0085] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.83,153.50,146.55,136.09,135.46,130.09,1 29.46,129.24,129.07,128.97,128.69,128.33,128.13,122.72,51.85,46.73;

[0086] MS(EI,70eV)m / z 392,304,121,91,77.

[0087] Example 4

[0088] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0089]

[0090] 0.2 mmol of 2-bromophenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 67% and a purity of 99.9%.

[0091] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0092] 1 H NMR (400MHz, CDCl3, ppm) δ7.57-7.53(m,3H),7.32-7.18(m,9H),6.97-6.90(m,2H),5.14-5.00(m,3H).

[0093] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.87,155.04,146.72,135.89,135.35,133.41,129.25,1 29.22,128.96,128.59,128.31,128.07,125.99,121.79,121.78,116.67,52.05,46.83;

[0094] MS(EI,70eV)m / z 438,357,121,91,77.

[0095] Example 5

[0096] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0097]

[0098] 0.2 mmol of 3-bromophenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 74% and a purity of 99.9%.

[0099] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0100] 1 H NMR (400MHz, CDCl3, ppm) δ7.48-7.46 (m, 2H), 7.31-7.10 (m, 11H), 6.90 (dd, J = 7.8, 2.0Hz, 1H), 5.07-4.94 (m, 3H).

[0101] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.83,153.99,149.40,136.01,135.37,130.70,129.26,1 29.06,129.00,128.72,128.35,128.16,127.73,124.46,122.90,120.04,51.90,46.74;

[0102] MS(EI,70eV)m / z 438,320,121,91,77.

[0103] Example 6

[0104] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0105]

[0106] 0.2 mmol of 4-bromophenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 74% and a purity of 99.9%.

[0107] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0108] 1 H NMR (400MHz, CDCl3, ppm) δ7.48-7.46(m,2H),7.41-7.23(m,10H),6.87-6.84(m,2H),5.08-4.95(m,3H)

[0109] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.81,153.44,147.02,136.05,135.42,132.40,1 29.24,129.06,128.97,128.68,128.32,128.12,123.13,117.87,51.86,46.73;

[0110] MS(EI,70eV)m / z 438,320,121,91,77.

[0111] Example 7

[0112] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0113]

[0114] 0.2 mmol of 4-methoxyphenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 81% and a purity of 99.9%.

[0115] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0116] 1 H NMR (400MHz, CDCl3, ppm) δ7.51-7.49(m,2H),7.32-7.24(m,8H),6.97-6.84(m,4H),5.10-4.94(m,3H),3.71(s,3H).

[0117] 13 C{1 H}NMR (100MHz, CDCl3, ppm) δ172.90,156.95,152.24,141.09,136.29,135.78,129. 15,129.06,128.82,128.60,128.32,127.98,122.34,114.58,55.52,51.71,46.66;

[0118] MS(EI,70eV)m / z 388,300,121,91,77.

[0119] Example 8

[0120] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0121]

[0122] 0.2 mmol of 3-methoxyphenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube and stirred for two hours. Then, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added, and the reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 74% and a purity of 99.9%.

[0123] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0124] 1 H NMR (400MHz, CDCl3, ppm) δ7.52-7.49(m,2H),7.34-7.19(m,9H),6.68-6.55(m,3H),5.12-4.99(m,3H),3.76(s,3H).

[0125] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.91,160.48,152.87,149.22,136.13,135.57,130.08,129. 14,129.06,128.83,128.58,128.28,127.98,113.44,110.34,107.08,55.35,51.75,46.63;

[0126] MS(EI,70eV)m / z 388,300,121,91,77.

[0127] Example 9

[0128] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0129]

[0130] 0.2 mmol of phenyl 2,4-dichloroisothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 61% and a purity of 99.9%.

[0131] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0132] 1 H NMR (400MHz, CDCl3, ppm) δ7.53-7.51 (m, 2H), 7.39-7.12 (m, 10H), 6.88 (d, J = 8.5Hz, 1H), 5.11-4.98 (m, 3H).

[0133] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.78,155.68,144.02,135.79,135.17,130.26,130.10,1 29.26,129.17,129.05,128.65,128.30,128.16,127.81,127.57,122.76,52.11,46.84;

[0134] MS(EI,70eV)m / z 426,307,121,91,77.

[0135] Example 10

[0136] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0137]

[0138] 0.2 mmol of phenyl 3,4-dichloroisothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 60% and a purity of 99.9%.

[0139] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0140] 1 H NMR (400MHz, CDCl3, ppm) δ7.47-7.44(m,2H),7.34-7.23(m,9H),7.10(q,J=2.4Hz,1H),6.82(dt,J=8.6,2.1Hz,1H),5.10-4.94(m,3H).

[0141] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.75,154.46,147.50,135.90,135.19,132.99,130.97,1 29.27,129.05,129.01,128.72,128.32,128.21,128.18,123.36,121.02,51.94,46.76;

[0142] MS(EI,70eV)m / z 426,307,121,91,77.

[0143] Example 11

[0144] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0145]

[0146] 0.2 mmol of 4-fluorophenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of 2-diazo-2-phenylacetic acid methyl ester was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 58% and a purity of 99.9%.

[0147] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0148] 1 H NMR (400MHz, CDCl3, ppm) δ7.51-7.48(m,2H),7.35-7.27(m,8H),7.04-6.93(m,4H),5.13-4.99(m,3H).

[0149] 13 C{ 1 H} NMR (100MHz, CDCl3, ppm) δ; 172.82, 161.27, 158.85, 153.21 (d, J = 1.0Hz), 143.95 (d, J = 2.0Hz), 135.75 (d, J = 57. 0Hz),129.16,128.98,128.87,128.57,128.23,127.98,122.55(d,J=8.0Hz),115.98(d,J=22.0Hz),51.74,46.64;

[0150] MS(EI,70eV)m / z 376,258,225,121,91,77.

[0151] Example 12

[0152] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0153]

[0154] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of m-chlorobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 50% and a purity of 99.9%.

[0155] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0156] 1 H NMR (400MHz, CDCl3, ppm) δ7.52 (t, J = 1.9Hz, 1H), 7.39-7.22 (m, 10H), 7.16-7.11 (m, 1H), 7.02-6.99 (m, 2H), 5.14-4.96 (m, 3H).

[0157] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.79,152.50,147.71,137.92,135.36,134.36,129.83,1 29.32,129.18,129.08,128.91,128.22,128.20,127.18,124.87,121.10,51.74,45.98;

[0158] MS(EI,70eV)m / z 392,274,257,125,77.

[0159] Example 13

[0160] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0161]

[0162] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of p-chlorobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 54% and a purity of 99.9%.

[0163] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0164] 1 H NMR (400MHz, CDCl3, ppm) δ7.47-7.43(m,2H),7.35-7.25(m,9H),7.14-7.10(m,1H),7.00-6.98(m,2H),5.10-4.94(m,3H).

[0165] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.86,152.59,147.78,135.42,134.60,133.93,1 30.66,129.37,129.20,128.93,128.76,128.25,124.90,121.14,51.76,45.91;

[0166] MS(EI,70eV)m / z 392,274,257,125,77.

[0167] Example 14

[0168] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0169]

[0170] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of o-bromobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 57% and a purity of 99.9%.

[0171] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0172] 1 H NMR (400MHz, CDCl3, ppm) δ7.67(t,J=1.8Hz,1H),7.41-7.37(m,2H),7.32-7.25(m,7H),7.15-7.07(m,2H),7.01-6.98(m,2H),5.07-4.91(m,3H).

[0173] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.81,152.60,147.80,138.32,135.48,132.06,131.20,1 30.24,129.43,129.25,128.97,128.31,127.74,124.97,122.64,121.23,51.79,45.97;

[0174] MS(EI,70eV)m / z 438,287,136,121,77.

[0175] Example 15

[0176] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0177]

[0178] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of m-bromobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 63% and a purity of 99.9%.

[0179] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0180] 1H NMR (400MHz, CDCl3, ppm) δ7.67(t,J=1.8Hz,1H),7.41-7.37(m,2H),7.32-7.25(m,7H),7.15-7.07(m,2H),7.01-6.98(m,2H),5.07-4.91(m,3H).

[0181] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.81,152.60,147.80,138.32,135.48,132.06,131.20,1 30.24,129.43,129.25,128.97,128.31,127.74,124.97,122.64,121.23,51.79,45.97;

[0182] MS(EI,70eV)m / z 438,287,136,121,77.

[0183] Example 16

[0184] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0185]

[0186] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of p-bromobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 66% and a purity of 99.9%.

[0187] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0188] 1 H NMR (400MHz, CDCl3, ppm) δ7.44-7.42(m,2H),7.39-7.25(m,9H),7.12(td,J=7.4,1.2Hz,1H),6.99(dt,J=8.3,1.6Hz,2H),5.10-4.92(m,3H).

[0189] 13 C{ 1H}NMR (100MHz, CDCl3, ppm) δ172.83,152.55,147.77,135.41,135.10,131.72,1 30.96,129.36,129.19,128.92,128.24,124.89,122.13,121.14,51.77,45.97;

[0190] MS(EI,70eV)m / z 438,287,136,121,77.

[0191] Example 17

[0192] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0193]

[0194] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 3-methylbenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 58% and a purity of 99.9%.

[0195] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0196] 1 H NMR (400MHz, CDCl3, ppm) δ7.32-7.16 (m, 10H), 7.10-7.06 (m, 2H), 6.99 (dq, J = 8.3, 1.3Hz, 2H), 5.08-4.94 (m, 3H), 2.30 (s, 3H).

[0197] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.96,152.84,148.11,138.25,136.16,135.75,129.77,129. 39,129.19,128.87,128.79,128.56,128.37,126.12,124.83,121.27,51.79,46.67,21.59;

[0198] MS(EI,70eV)m / z 372,284,254,105,77.

[0199] Example 18

[0200] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0201]

[0202] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 4-methylbenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 75% and a purity of 99.9%.

[0203] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0204] 1 H NMR (400MHz, CDCl3, ppm) δ7.42-7.40(m,2H),7.33-7.25(m,7H),7.12-7.08(m,3H),7.01-6.98(m,2H),5.8-4.94(m,3H),2.31(s,3H).

[0205] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.91,152.77,148.07,137.70,135.69,133.25,129. 33,129.28,129.16,129.15,128.82,128.32,124.77,121.23,51.77,46.43,21.31;

[0206] MS(EI,70eV)m / z 372,284,254,105,77.

[0207] Example 19

[0208] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0209]

[0210] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 3-methoxybenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 71% and a purity of 99.9%.

[0211] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0212] 1 H NMR (400MHz, CDCl3, ppm) δ7.46-.32(m,8H),7.24-7.11(m,5H),6.95(ddd,J=8.1,2.6,1.4Hz,1H),5.23-5.09(m,3H),3.85(s,3H).

[0213] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.90,159.81,152.81,148.02,137.63,135.66,129.63,129. 36,129.17,128.85,128.32,124.81,121.28,121.20,114.25,113.87,55.28,51.75,46.61;

[0214] MS(EI,70eV)m / z 388,300,270,121,77.

[0215] Example 20

[0216] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0217]

[0218] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 3,4-dichlorobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 57% and a purity of 99.9%.

[0219] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0220] 1 H NMR (400MHz, CDCl3, ppm) δ7.62 (d, J = 1.9Hz, 1H), 7.36-7.26 (m, 9H), 7.14-7.09 (m, 1H), 7.01-6.98 (m, 2H), 5.11-4.90 (m, 3H).

[0221] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.77,152.48,147.64,136.21,135.28,132.61,132.23,1 31.15,130.58,129.42,129.25,129.01,128.62,128.25,125.02,121.16,51.79,45.44;

[0222] MS(EI,70eV)m / z 426,308,275,159,77.

[0223] Example 21

[0224] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0225]

[0226] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 2-thiophene methylamine, and 2 mL of acetonitrile were added to a reaction tube and stirred for two hours. Then, 0.1 mmol of 2-diazo-2-phenylacetic acid methyl ester was added, and the reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 63% and a purity of 99.9%.

[0227] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0228] 1 H NMR (400MHz, CDCl3, ppm) δ7.34-7.30(m,2H),7.27-7.17(m,7H),7.12-7.04(m,3H),6.90(dd,J=5.1,3.5Hz,1H),5.23-5.03(m,3H).

[0229] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.35,152.26,147.90,137.37,135.55,129.41,1 29.19,128.88,128.63,128.35,126.68,126.33,124.93,121.30,51.87,41.06;

[0230] MS(EI,70eV)m / z 364,269,246,97,77.

[0231] Example 22

[0232] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0233]

[0234] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of 3-fluorobenzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-diazo-2-phenylacetate was added. The reaction was stirred for 2 hours under 10W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 54% and a purity of 99.9%.

[0235] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0236] 1 H NMR (400MHz, CDCl3, ppm) δ7.35-7.21(m,10H),7.14-7.10(m,1H),7.01-6.97(m,3H),5.13-4.98(m,3H).

[0237] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.81,164.07,161.62,152.56,147.75,138.39(d,J=8.0Hz),135.39,130.09(d,J=8.0Hz),129.26 (d,J=15.0Hz),128.91,128.23,124.88,124.62(d,J=2.0Hz),121.13,115.89(d,J=22.0Hz),114.96(d,J=21.0Hz),51.74,46.06;

[0238] MS(EI,70eV)m / z 376,257,225,121,109,77.

[0239] Example 23

[0240] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0241]

[0242] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-(4-methoxyphenyl)-2-diazoacetic acid was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 52% and a purity of 99.9%.

[0243] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0244] 1H NMR (400MHz, CDCl3, ppm) δ7.52-7.50(m,2H),7.33-7.08(m,8H),7.01-6.98(m,2H),6.85-6.82(m,2H),5.12-4.99(m,3H),3.73(s,3H).

[0245] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ173.19,159.95,152.82,148.01,136.20,129.48,129. 29,129.07,128.57,127.96,127.47,124.73,121.19,114.56,55.39,51.33,46.59;

[0246] MS(EI,70eV)m / z 388,240,148,91,77.

[0247] Example 24

[0248] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0249]

[0250] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-(4-bromophenyl)-2-diazoacetic acid was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 73% and a purity of 99.9%.

[0251] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0252] 1 H NMR (400MHz, CDCl3, ppm) δ7.50-7.47(m,2H),7.38-7.35(m,2H),7.32-7.24(m,5H),7.11-7.07(m,3H),7.00-6.97(m,2H),5.08-4.95(m,3H).

[0253] 13 C{ 1H}NMR (100MHz, CDCl3, ppm) δ172.43,152.34,147.89,136.10,134.64,132.31,1 30.05,129.47,129.16,128.73,128.18,124.99,123.05,121.24,51.12,46.80;

[0254] MS(EI,70eV)m / z 438,273,240,91,77.

[0255] Example 25

[0256] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0257]

[0258] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-(4-chlorophenyl)-2-diazoacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 71% and a purity of 99.9%.

[0259] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0260] 1 H NMR (400MHz, CDCl3, ppm) δ7.51-7.48(m,2H),7.34-7.24(m,7H),7.20-7.16(m,2H),7.13-7.09(m,1H),7.00-6.98(m,2H),5.10-4.97(m,3H).

[0261] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.49,152.27,147.85,136.04,134.84,134.05,1 29.68,129.39,129.33,129.12,128.66,128.11,124.92,121.15,51.04,46.75;

[0262] MS(EI,70eV)m / z 392,240,155,91,77.

[0263] Example 26

[0264] The 2-iminothiazolidin-4-one compounds obtained in this embodiment have the following structures:

[0265]

[0266] 0.2 mmol of phenyl isothiocyanate, 0.2 mmol of benzylamine, and 2 mL of acetonitrile were added to a reaction tube. After stirring for two hours, 0.1 mmol of methyl 2-(3-bromophenyl)-2-diazoacetate was added. The reaction was stirred for 1.5 h under 10 W white LEDs. After the reaction was completed, the product was purified by column chromatography. The eluent used for column chromatography was a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 10:1. The purified target product, 2-iminothiazolidin-4-one compounds, was obtained with a yield of 46% and a purity of 99.9%.

[0267] The structure of the obtained product was characterized, and the structural characterization data are as follows:

[0268] 1 H NMR (400MHz, CDCl3, ppm) δ7.51 (dt, J = 7.7, 1.7Hz, 2H), 7.44-7.39 (m, 2H), 7.35- 7.28(m,5H),7.22-7.10(m,3H),7.00(dq,J=8.3,1.5Hz,2H),5.12-4.99(m,3H).

[0269] 13 C{ 1 H}NMR (100MHz, CDCl3, ppm) δ172.25,152.08,147.77,137.68,135.98,132.00,131.31,1 30.61,129.37,129.08,128.65,128.10,127.03,124.93,123.07,121.13,51.02,46.78;

[0270] MS(EI,70eV)m / z 438,273,240,91,77.

[0271] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a 2-iminothiazolidin-4-one compound, characterized in that, Includes the following steps: A phenyl isothiocyanate compound, an amine compound, an aryl diazo ester compound, and a polar organic solvent are mixed and subjected to a coupling addition reaction to obtain the 2-iminothiazoline-4-one compound. The coupling addition reaction is carried out under illumination; the illumination is 10W white LEDs. The phenyl isothiocyanate compounds are selected from one or more of the following: phenyl isothiocyanate, 3-chlorophenyl isothiocyanate, 4-chlorophenyl isothiocyanate, 2-bromophenyl isothiocyanate, 3-bromophenyl isothiocyanate, 4-bromophenyl isothiocyanate, 4-methoxyphenyl isothiocyanate, 3-methoxyphenyl isothiocyanate, 2,4-dichlorophenyl isothiocyanate, 3,4-dichlorophenyl isothiocyanate, and 4-fluorophenyl isothiocyanate. The amine compound is selected from one or more of benzylamine, m-chlorobenzylamine, p-chlorobenzylamine, o-bromobenzylamine, m-bromobenzylamine, p-bromobenzylamine, 3-methylbenzylamine, 4-methylbenzylamine, 3-methoxybenzylamine, 3,4-dichlorobenzylamine, 2-thiophene methylamine, and 3-fluorobenzylamine; The aryl diazonium esters are selected from one or more of methyl 2-diazo-2-phenylacetate, methyl 2-(4-methoxyphenyl)-2-diazoacetate, methyl 2-(4-bromophenyl)-2-diazoacetate, methyl 2-(4-chlorophenyl)-2-diazoacetate, and methyl 2-(3-bromophenyl)-2-diazoacetate.

2. The preparation method according to claim 1, characterized in that, The polar organic solvent includes acetonitrile, dichloromethane, or ethyl acetate.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the phenyl isothiocyanate compound, the amine compound, and the aryl diazo ester compound is 2:2:

1.

4. The preparation method according to claim 1 or 3, characterized in that, The ratio of the polar organic solvent to the phenyl isothiocyanate compound is 1L:0.1~0.2mol.

5. The preparation method according to claim 1, characterized in that, The coupling addition reaction is carried out at room temperature for 1.5 to 3 hours.

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