Preparation process for ketene used for novel bactericide--tebuconazole

Abstract

The invention discloses a preparation process for ketene used for a novel bactericide--tebuconazole. The preparation process is characterized by comprising the following steps: adding ketene into methanol, carrying out high speed beating with a beater, then adding a catalyst, carrying out hydrogenation to prepare pentanone and carrying out washing by using hydrochloric acid neutralization washing technology and high speed separation technology so as to prepare ketene used for the novel bactericide--tebuconazole. The preparation process provided by the invention overcomes the problems of a high hydrogenation temperature, hydrogenation safety and a great side reaction in the prior art, prolongs the service life of reaction equipment, reduces reaction danger and allows dechlorinated pentanone produced in a side reaction to decrease from original 0.25% to less than 0.1%, p-chlorobenzyl alcohol to decrease from original 0.4% to 0.2% and the main content of pentanone to increase to more than 99% from original 98%.

Description

technical field [0001] The invention relates to a preparation process of enone for novel fungicide tebuconazole. Background technique [0002] Fungicides are a class of pesticides used to prevent and control plant diseases caused by various pathogenic microorganisms, generally referring to fungicides. However, internationally, it is usually used as a general term for agents to prevent and control various pathogenic microorganisms. With the development of fungicides, subclasses such as bactericides, virucides, and algicides are distinguished. According to the survey, there are more than 80,000 kinds of pathogenic microorganisms (fungi, strong bacteria, rickettsia, mycoplasma, viruses, algae, etc.) harmful to plants in the world. The use of fungicides is a cost-effective method of controlling plant diseases. [0003] Early fungicides were all inorganic compounds, among which sulfur powder and copper preparations (such as Bordeaux mixture) are still used today. In the 1940s...

AI Technical Summary

Problems solved by technology

[0004] Occurred at present is a kind of novel bactericide tebuconazole, and its bactericidal effect is good, and pollution is little, and the harm to environment is also little, is a kind of comparatively ideal bactericide, but, the main material pentaconazole of existing tebuconazole The preparation process of ketone is relatively backward. Most of them are condensed with p-chlorobenzaldehyde and pinacolone, and then hydrogenated to make products. There are disadvantages such as low content, low yield, and low transparency, which seriously restrict the development of tebuconazole