Diazoxide preparation method

[0032] Preparation of compound 3:

[0033]

[0034] Add p-compound 1 (100g) and chlorobenzene (560ml) into a 1L flask, stir and heat to dissolve, set aside. Add compound 2 (120g) and chlorobenzene (280ml) into a 2L three-necked flask, stir and cool down to 10°C, add the spare p-chloroaniline solution dropwise, and control the temperature during the dropping process at 10°C. Add aluminum trichloride (100g) after dropping, remove the cooling bath, then slowly heat up to 100°C to react for 2 hours, stop heating, and lower the temperature. Prepare another 3L three-necked bottle, add water (1L), and under rapid stirring, slowly pour the reaction solution into water, stir, and suction filter. The filter cake was air-dried for 5 hours to obtain compound 3 with a yield of 59.6% and a purity of 97.7%.

[0035] Preparation of diazoxide:

[0036]

[0037] Add compound 3 (100g), acetic acid (500g) and 98% sulfuric acid (350g) into a 2L three-necked flask and stir, slowly heat to 120

[0039] Preparation of compound 3:

[0040]

[0041] Add p-compound 1 (100g) and chlorobenzene (560ml) into a 1L flask, stir and heat to dissolve, set aside. Add compound 2 (120g) and chlorobenzene (280ml) into a 2L three-necked flask, stir and cool down to 10°C, add the spare p-chloroaniline solution dropwise, and control the temperature during the dropping process at -10°C. Add aluminum trichloride (100g) after dropping, remove the cooling bath, then slowly heat up to 100°C to react for 2 hours, stop heating, and lower the temperature. Prepare another 3L three-necked bottle, add water (1L), and under rapid stirring, slowly pour the reaction solution into water, stir, and suction filter. The filter cake was air-dried for 5 hours to obtain compound 3 with a yield of 59.8% and a purity of 98.5%.

[0042] Preparation of diazoxide:

[0043]

[0044] Add compound 3 (100g), acetic acid (500g) and 98% sulfuric acid (350g) into a 2L three-necked flask and stir, slowly heat to 120°