Studies On The New Synthesis Technics Of Difenoconazole And Its Recycle

Difenoconazole is a kind of triazole bactericide with special action mechanism, which is highly active, broad-spectrum, low mammalian toxicity and low dosage. It can prevent diseases like scab, powdery midew, rust and anthrax caused by fungus and adelomycete in the plants, it can control multiple plant diseases once with duration. Now, it is an ideal medicine dealing with resistant bacteria in our country even in the whole world. There are so many residues in its synthesis waste, and couldn’t process at present. Therefore, it is so important and significant to studies on the synthesis technics of difenoconazole and its waste disposal.High efficiency liquid chromatography was used to analyze the waste and separation operation was made through column chromatography. The element and content of the waste was obtained. The structure and purity of the separative product was characterized by a number of test techniques such as melting point meter, infrared Absorption Spectroscopy,1HNMR,13CNMR, MS, X-raysingle crystal diffraction, and so on. The contents of difenoconazole was maximum in the waste, reached up to34.0%(butt, same below) and it is worth to recycle. The main byproduct in the waste is difenoconazoleisomer,3-Chloro-4-[4-Methyl-2-(4h-1,2,4-Triazole-l-Methyl)-1,3-Dioxylpentane-2-] Phenyl-4-Chlorophenyl Ether, its content is25.2%.After analyzing the crystallization processes of byproduct and difenoconazole, this paper successfully recycle difenoconazole from its waste using adductive crystallization technology. Frist step, the waste was treated with methanol and ethanol, part of impurities was removed, and the stable system was destroyed. Then, hydrogen nitrate was added and difenoconazole was separated out as a salt, when dosage of hydrogen nitrate was1.04times of theoretical quantity, total recovery ratio was52.2%. This process have the benefits of good economic.N-alkylation of1,2,4-triazole mechanism and process was made, and synthesis technics of this step was optimized. The suitable condition of synthesis technics is: DMF as the solvent, K2CO3as deacid reagent, and PEG600as phase transfer catalyst, the ratio of deacid reagent, phase transfer catalyst,1,2,4-triazole and bromide was 150mL:4.14g:0.9g:2.41g:12.54g. Reaction temperature145℃,the reaction time was2.0h. the product yields up to95.2%.