Novel synthesis method of metconazole

Abstract

The invention relates to the technical field of synthesis of pesticide products, and particularly discloses a novel synthesis method of metconazole, which specifically comprises the following steps: reacting succinic acid with propionyl chloride to obtain 2-methyl-1, 3-cyclopentanedione; then carrying out methylation to generate 2, 2-dimethyl-1, 3-cyclopentanedione; the preparation method comprises the following steps: firstly, preparing 2, 2-dimethyl-3-hydroxycyclopentanedione from 2, 2-dimethyl-3-hydroxycyclopentanedione in the presence of a catalyst and oxazoleborane, and carrying out elimination reaction to obtain 2, 2-dimethyl-3-alkene cyclopentanone; the preparation method comprises the following steps: adding 2, 2-dimethylcyclopentanone into a reaction kettle, adding hydrogen to generate 2, 2-dimethylcyclopentanone, and reacting 2, 2-dimethylcyclopentanone with p-chlorobenzyl chloride to generate 2, 2-dimethyl-5-(4-chlorobenzyl)-cyclopentane-1-ketone; then carrying out a reaction to generate 7-(4-chlorobenzyl)-4, 4-dimethyl-1-oxo-spiro [2, 4] heptane; and finally, reacting with sodium triazole to generate metconazole. The synthesis route of metconazole does not need to use highly toxic materials such as sodium cyanide or methyl magnesium bromide, and does not need the reaction condition of-50 DEG C, so that the production safety is improved, the equipment cost and the raw material cost are reduced, the green development concept is met, and the metconazole is suitable for long-term industrial development.

Description

technical field [0001] The present application relates to the field of synthetic technology of pesticide products, more specifically, it relates to a new synthetic method of metconazole. Background technique [0002] Metconazole, commonly known as Metconazole in English, and trade name as Caramba, is a new broad-spectrum systemic fungicide. It has excellent protective and therapeutic effects, and the field application of metconazole has excellent effects on the plant diseases of Concha, Alternaria and Pseudomonas on cereal crops. Metconazole's bactericidal mechanism of action is a C-14 demethylase inhibitor in ergosterol biosynthesis. Although the mechanism of action is the same as other triazole fungicides, the activity spectrum is quite different. Compared with traditional fungicides, the dose is extremely low and the control of cereal plant diseases is very broad. It has been registered for the control of wheat scab, powdery mildew and rust. [0003] Metconazole is a c...

AI Technical Summary

Problems solved by technology

[0005] First, using isobutyronitrile as a raw material, lithium bis(trimethylsilyl)amide or lithium dimethylamide needs to be used in the process. These compounds are not common and expensive; secondly, sodium cyanide is also used. It is highly toxic, and it is prone to accidents in industrial production, with a high risk factor. In addition, the purification of its intermediates requires too much equipment, which will greatly increase production costs.

[0006] The second, with 2,2-dimethylcyclopentanone as raw material, although this route is shorter, its raw material is more expensive, and synthetic process is longer, and relates to the use of sodium cyanide, methylmagnesium bromide, also The temperature requirement of -50°C also has a large risk factor and high production cost, so it is not suitable for industrial production

[0007] The third, with 2-ethoxycarbonyl cyclopentanone as raw material, the sequence of unit operations such as methylation reaction, condensation reaction, hydrolysis decarboxylation reaction, reduction reaction, epoxidation reaction in the preparation of metconazole has an impact on the yield of the final product. The efficiency and purification have a great influence, especially in the process of two-step methylation reaction, which is highly toxic and difficult to operate, so there are still difficulties in the preparation method of metconazole