Preparation method of 3-aminopyrazoles-4-formamide hemisulphate

The invention relates to a preparation method of 3-aminopyrazoles-4-formamide hemisulphate, which comprises the following steps of: 1, reacting cyanoacetamide, morpholine and (RO)3CH for 2-6 hours in a polar solvent, and removing a liquid part in a reaction system by means of distillation or filtering; 2, adding water and hydrazine hydrate into the reaction system to continuously react for 10-60min; 3, regulating the temperature of the reaction system to be 5-80 DEG C and regulating the PH value of the reaction system to be between 0.5 and 3 by using concentrated sulfuric acid, and reacting for 0.1-5h; and 4, carrying out suction filtration on the reaction system, washing a filtering cake by sequentially using the water and the organic solvent, and recrystallizing the filtering cake to obtain the 3-aminopyrazoles-4-formamide hemisulphate. The method has the advantages of simple process, low cost and easy acquisition of raw materials, high purity of the prepared product, low-toxicity and environment-friendly technique and greater application promotional value, is prepared by carrying out the reaction step by step or continuously carrying out the reaction in the same reactor, and can greatly reduce the cost.