Preparation method of 5-amido-1,2,4-selenadiazole derivative

[0025] The invention provides a method for preparing 5-amino-1,2,4-selenodiazole derivatives under metal-free conditions, comprising:

[0026] The amidine hydrochloride shown in formula (I) and the isocyanide compound shown in formula (II), and selenium powder are reacted under the condition that basic compound exists, obtain 5-amino group-1,2,4- Selenium diazole derivatives;

[0027] R 2 -NC type (Ⅱ);

[0028] The preparation method provided by the present invention adopts non-toxic selenium powder as the selenium source, and does not require the participation of metals, and only needs the presence of organic bases and air atmosphere; at the same time, the amidine hydrochlorides and isonitriles used have a wide range of structures, and the aryl Or alkyl substrates can react smoothly, with high substrate universality; and the operation is simple, only simple heating is required, and the reaction can be completed in 4 to 6 hours, the reaction time is short, and the reaction...

[0042] The preparation of embodiment 1N-(4-nitrophenyl)-3-phenyl-1,2,4-selenodiazol-5-amine

[0043]

[0044] N-(4-nitrophenyl)-3-phenyl-1,2,4-selenadiazol-5-amine

[0045] Take a clean reaction tube, add a suitable size magnetic stirrer, add 0.3mmol 4-nitrobenzene isonitrile, 0.45mmol benzamidine hydrochloride and 0.45mmol selenium powder, add 3mL acetonitrile (MeCN) as a solvent, add 0.75mmol N , N-diisopropylethylamine (DIPEA), stirred in an oil bath at 80°C, reacted for 4 hours, followed the reaction progress by thin-layer chromatography until the end of the reaction. Transfer the reaction system to an eggplant-shaped flask, add silica gel powder for column chromatography, remove the solvent by rotary evaporation, and separate by column chromatography to obtain the target product N-(4-nitrophenyl)-3-phenyl-1,2, 4-Selenodiazol-5-amine, pale yellow solid. Yield: 90%.

[0046] Proton NMR spectrum (DMSO, 400MHz) (δ, ppm): δ11.47(s,1H),8.35–8.27(m,2H),8.26–8.19(m,2H),8.03–7...

[0049] The preparation of embodiment 2N-(3-nitrophenyl)-3-phenyl-1,2,4-selenodiazol-5-amine

[0050]

[0051] N-(3-nitrophenyl)-3-phenyl-1,2,4-selenadiazol-5-amine

[0052] Take a clean reaction tube, add a suitable size magnetic stirrer, add 0.3mmol 3-nitrobenzene isonitrile, 0.45mmol benzamidine hydrochloride and 0.45mmol selenium powder, add 3mL acetonitrile (MeCN) as a solvent, add 0.75mmol N,N-diisopropylethylamine (DIPEA), stirred in an oil bath at 80°C, reacted for 4 hours, followed the reaction progress by thin-layer chromatography until the end of the reaction. Transfer the reaction system to an eggplant-shaped flask, add silica gel powder for column chromatography, remove the solvent by rotary evaporation, and separate by column chromatography to obtain the target product N-(3-nitrophenyl)-3-phenyl-1,2, 4-Selenodiazol-5-amine, pale yellow solid. Yield: 82%.

[0053] Proton NMR spectrum (DMSO, 400MHz) (δ, ppm): δ11.56(s, 1H), 9.06(t, J=2.3Hz, 1H), 8.22(dd, J=7.7...