Method for preparing cycloxylidin

Abstract

The invention discloses a method for preparing cycloxylidin, which belongs to the technical field of pesticides preparation. The method comprises the following steps: under nitrogen protection, N-nitroiminoimidazolidine and an organic solvent are added in a reactor, then sodium hydride is added in batches, and the material is heated to the temperature of 50-60 DEG C, chloropropylene oxide is added drop by drop in the reactor, after the reaction product is cooled, chloroform is added, and the product is filtered by diatomite, then evaporative crystallization is carried out, and the crystals can be precipitated, vacuum distillation is carried out on a processed filtrate to obtain a light yellow dense solid, then heat chloroform is used for extraction, and finally heat ethanol or acetone is used for recrystallization to obtain cycloxylidin: 1-(2,3-glycidyl)-N-nitroimidazoline-2-ylamine, wherein the yield is about 83%. The method has the advantages of short reaction time, high yield and green environmental protection, and is more suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of insecticide preparation, and in particular relates to a preparation method of 1-(2,3-epoxypropyl)-N-nitroimidazolidin-2-ylamine, namely epoxyline. Background technique [0002] Epoxyline is based on the computer-aided drug design (CADD) method, that is, using the COMFA simulation results, the insecticidal effect of the four neonicotinoid compounds synthesized is the best, and its insecticidal activity is the largest in the global market. Insecticides - imidacloprid has comparable insecticidal activity. However, the widespread use of imidacloprid has resulted in a certain degree of drug resistance in pests, and the raw material pyridine used in the synthesis of imidacloprid is not only costly, but also produces a large amount of pollutants in the production process. Epoxypridine can not only effectively overcome the above shortcomings, but also has good insecticidal effect like imidacloprid, and has lower...

AI Technical Summary

Problems solved by technology

In 2009, Chinese patent CN101503406A disclosed two synthetic routes of 1-(2,3-epoxypropyl)-N-nitroimidazolidin-2-ylamine. Route 1 adopts a two-step synthetic method, first while stirring While adding epichlorohydrin dropwise to ethylenediamine, at a temperature of about 45°C, react for 2 to 3 hours and then distill off the solvent under reduced pressure to obtain the intermediate epoxypropylethylenediamine, and then dissolve the intermediate and nitroguanidine In water, add dilute hydrochloric acid dropwise while stirring, react at about 85°C for 2 to 3 hours, then cool, extract with dichloromethane, distill off the solvent under reduced pressure, recrystallize with methyl ethyl ketone, two-step reaction, the reaction temperature is higher, and The post-treatment process needs to use a large amount of dichloromethane and other solvents for extraction, so the product has little industrial value

Route 2: First, add N-nitroimidazolidine, potassium carbonate and organic solvent into the reaction flask, heat to 80°C, and then add epichlorohydrin dropwise to it after the reactants are dissolved. The reaction ends after heating for 4 hours, and then cools down to room temperature After filtering, the filtrate was evaporated to dryness, and the resulting residue was added with water, then extracted with dichloromethane, the solvent was distilled off under reduced pressure, and then recrystallized with butanone. production application

Images