121results about How to "The post-processing method is simple" patented technology

The invention relates to a method for preparing 2-amino-4,6-dichloro-5-formamido pyrimidine. The method comprises the following steps of: performing nitrosation on malonic acid diethyl ester and acetic acid serving as raw materials and sodium nitrite at first; then, performing reduction and formylation with formic acid in the presence of zinc powder to form formyl amino malonic acid diethyl ester; finally, performing condensation and cyclization with guanidine hydrochloride to produce 2-amino-4,6-dichloro-5-formamido pyrimidine; performing chlorination by using quaternary ammonium salt as a catalyst; fractionally performing hydrolysis under an alkali action to obtain a product. The method has easily-available raw materials, and is short in reaction time, simple in aftertreatment and high in hydrolysis selectivity; the cost is obviously reduced; the total yield is up to 74 percent and the purity of the product is up to 99.0 percent.

The invention provides a method for preparing tetrabenzyl pyran type hexose, belonging to the field of sugar compounds. The method adopts a supported solid-acid catalyst namely silica gel supported sulfuric acid-hydrofluoric acid, performs catalytic hydrolysis on tetrabenzyl pyran type hexose glucoside, is simple in operation, is environment-friendly and practical, and simplifies an after-treatment method. The method comprises the steps of adding tetrabenzyl pyran type hexose glucoside and an organic solvent at room temperature, adding silica gel supported sulfuric acid-hydrofluoric acid, completing reaction, and then performing after-treatment to obtain tetrabenzyl pyran type hexose. The preparation method provided by the invention is simple in operation and easy in reaction control, reduces the cost, and is beneficial for environmental protection.

The invention relates to a preparation method of a prothioconazole intermediate. The preparation method comprises the following steps: dissolving [1-(2-chlorophenyl)-2-(1-chlorocyclopropyl)-2-hydroxy]-propyl hydrazine into methyl benzene; dropwise adding a formaldehyde aqueous solution or a polyformaldehyde aqueous solution under 30 to 35 DEG C; then adding in thiocyanate after completion of dropwise adding; then dropwise adding hydrochloric acid or sulfuric acid aqueous solution; keeping warm and reacting for 50 to 70 minutes after completion of dropwise adding; directly using a reaction solution for follow-up reaction or filtering the reaction solution after cooling; thus obtaining the prothioconazole intermediate 2-(1-chloro-cyclopropyl-1-yl)-1-(2-chlorophenyl)-2-hydroxy-3-(1,2,4-triazolidine-5-thioketone-1-yl)-propane. Through optimization on a whole route, for example, reaction temperature, reagents, a feeding procedure and the like, of the preparation method, an after-treatment method is simple, three wastes such as waste gas, waste water and waste residues are few, the reaction time is shortened, the purity and the yield of a product are higher, and the preparation method is suitable for industrial production.