3 results about "Dichlorobutane" patented technology

The present invention discloses a method for synthesizing carbazole. Using indole and 1,4-dichlorobutane as raw materials, the final product carbazole is obtained through a one-step reaction. The method of the present invention has the advantages of cheap and easily available raw materials, convenient production and easy purification, and can be developed into an industrial production method.

This invention relates to the field of pharmaceutical synthesis technology, and in particular to a method for removing viscous impurities during the synthesis of hexahydropyridazine, comprising the following steps: 1,2-dicarboxyhydrazide reacts with 1,4-dichlorobutane in stages under alkaline and potassium bromide catalytic conditions. After the reaction is complete, the mixture is filtered and distilled under reduced pressure to obtain a concentrated tetrahydropyridazine-1,2-dicarboxaldehyde solution. The concentrated tetrahydropyridazine-1,2-dicarboxaldehyde solution is then subjected to ethyl acetate extraction, dehydration and decolorization, cooling for impurity removal, and reduced pressure distillation to obtain purified tetrahydropyridazine-1,2-dicarboxaldehyde. The purified tetrahydropyridazine-1,2-dicarboxaldehyde is dissolved in anhydrous ethanol, and ethanol-hydrochloride is added dropwise while maintaining the temperature for reaction. After the reaction is complete, the mixture is crystallized, filtered, washed, and dried to obtain hexahydropyridazine dihydrochloride. This invention not only reduces and prevents side reactions and effectively removes viscous impurities, but also has low energy consumption and improves the product yield and purity of hexahydropyridazine dihydrochloride.

The invention provides a method for preparing 3, 3 '-[1, 4-butyl bis (oxymethylene)]-bis-(3-ethyl) oxetane. The invention relates to a conversion process for preparing 3, 3 '-[1, 4-butyl bis (oxymethylene)]-bis-(3-ethyl) oxetane through a reaction between 3-ethyl-3-oxetane methanol and 1, 4-dichlorobutane by taking 3-ethyl-3-oxetane as a raw material, taking potassium hydroxide as an alkaline reagent and adopting a quaternary ammonium salt or quaternary phosphonium salt phase transfer catalyst. Compared with the prior art, the method has the advantages that the reaction is promoted by dropwise adding the 1, 4-dichlorobutane and distilling the water while dropwise adding the 1, 4-dichlorobutane, the product with higher content and lower color number can be obtained without distilling the product, and compared with the traditional one-pot method, the production efficiency, the product yield and the purity are improved, the color number of the product is reduced, and the method is suitable for industrial mass production.