In the pharmaceutical field, intermediates are an important link in the pharmaceutical industry chain, used in the process of drug synthesis of some chemical raw materials or chemical products, in a word, for the production of API.
And pesticide intermediates are also intermediate media that combine two or more agricultural raw materials together. Today, we mainly talk about pesticide intermediates.
Pesticides are used to prevent, destroy or control diseases, insects, grasses and other pests that harm agriculture, forestry and purposely regulate the growth of plants, insects, chemical synthesis or from biological, other natural substances of a substance or a mixture of several substances and their preparations. Broadly speaking, pesticides are divided into crop protection pesticides and non-crop protection pesticides, crop protection pesticides are mainly divided into herbicides, insecticides, fungicides and plant growth regulators, etc., mainly used in agricultural protection; non-crop protection pesticides mainly include rodenticides, insect repellents, health mosquito supplies, etc., mainly used in residential medicine, public health, forestry management, industrial mold, pest control, seasonal seasonal medicine, wood preservation, lawn protection and other fields.
The pesticide industry is at the end of the chemical industry chain and belongs to the fine chemical industry. Upstream of the pesticide industry chain are petroleum/chemical industries, which provide raw materials for the pesticide industry; midstream industries mainly include intermediates, prodrugs and formulations; downstream are agricultural applications and non-agricultural applications. The pesticide industry is highly dependent on technology, with high investment in R&D, long lead time, high risk and low success rate. Under the contradiction of global population growth and decreasing arable land, the extensive use of pesticides to improve the yield per unit area is an important way to solve the food problem.
Pesticides are important production materials in agricultural production and play an extremely important role in controlling pests, diseases and weeds, stabilizing and improving crop yields. Although affected by the price of agricultural products, planting area, climate, inventory and many other factors, pesticide sales will show certain cyclical fluctuations from year to year, but demand is still relatively rigid. According to the National Bureau of Statistics, since 2017, the national production of chemical pesticides has shown a declining trend. 2017 chemical pesticide production of 2.941 million tons, fell to 2.083 million tons in 2018, 2019 chemical pesticide production stopped rising, production of 2.253.9 million tons, an increase of 1.4%. And in recent years, the overall sales revenue of China’s pesticide industry has maintained an improving trend. 2018, thanks to the development of biological pesticides and the rise in product prices, as well as the expansion of demand for pesticides in cash crops such as cotton and infrastructure, the industry’s sales revenue was about 329 billion yuan; it is expected that the potential market size of China’s agriculture is still expected to become an upward trend in 2020.
Different pesticides require different intermediates in the production process. Agricultural raw materials processed to produce the product, but also an intermediate medium that combines two or more substances together. In the pesticide can be understood as synergists, also known as organic intermediates. Initially refers to the intermediates produced in the process of synthesizing chemical products such as fragrances, dyes, resins, drugs, plasticizers, rubber accelerators, etc. using coal tar or petroleum products as raw materials.
The synthesis of intermediates is generally carried out in the reactor, and the generated intermediates should be separated and purified, which is usually achieved by extraction technology. Chloroform extraction of pesticide intermediates is a common unit of operation in chemical enterprises, the traditional operation process generally uses the distillation tower operation, such operation process is complex, low extraction efficiency, power consumption, so with the deepening of the division of labor and the progress of production technology, most enterprises began to carry out technological changes, choose a more effective process for operation. Among them, solvent extraction method began to become the main operating unit of the extraction section in the chemical industry. The solvent extraction method is to choose a suitable extractant, the raw material liquid and the extractant to mix, the organic phase in the raw material liquid transferred to the extractant, the organic phase is extracted after the separation of the two phases. This method is simple to operate, high extraction efficiency, extractant is cheap and easy to obtain, while the extractant can be recycled, effectively saving comprehensive input costs.
Diethyl maleate is also a pesticide intermediate, used in the preparation of organophosphorus pesticide malathion, and also used in the production of fragrances.