The invention discloses a preparation method of
miconazole nitrate. The method comprises steps as follows: 2,4-dichloro-2'-chlorinated
phenethyl alcohol,
imidazole and 2,4-dichlorobenzyl are used as raw materials, an
ionic liquid is used as a reaction medium, a reaction is conducted at the temperature 10-100 DEG C, a reaction liquid is cooled to the
room temperature after the reaction is finished, the pH value of the reaction liquid is adjusted to range from 1 to 3 by the aid of a
nitrate aqueous solution with the
volume concentration of 15-50%, the reaction liquid is left to stand for layering, the lower layer is taken for
recovery of the
ionic liquid, the upper layer is taken for pressure
reduced concentration until a
solid is separated out, a concentrate is taken and cooled to the
room temperature, then a recrystallization
solvent is added to the concentrate for recrystallization, crystals are taken and dried, and the
miconazole nitrate is obtained. According to the method, the
ionic liquid is used as the reaction medium, and a one-pot reaction technology is combined; the method has the technical characteristics that the operation is simple and convenient, the reactions are safe, the yield is high, the ionic liquid can be reused continuously after a product is separated out, the method is environment-friendly and the like.