Preparation method of snail killing agent crude medicine niclosamide

Abstract

A process for preparing the teniarene used to prepare molluscacide includes reflux reacting between 5-chlorosalicyclic acid and 2-chloro-4-nitrophenylamine in xylene under action of composite catalyst, cooling, filtering, washing the deposit with water 2-3 times, washing with composite organic solvent 2-3 times, and drying at 105 deg.C.

Description

technical field [0001] The invention relates to a preparation method of a molluscicide, in particular to a preparation method of niclosamide used as a molluscicide in aquaculture and schistosomiasis departments. Background technique [0002] In aquaculture, snail damage is one of the important sources that affect the normal growth of aquatic organisms, and its damage is mainly manifested in the following points: [0003] 1) Compete with fish and shrimp, increase the amount of feed input, and reduce the growth rate of fish and shrimp. [0004] 2) Snails and mussels increase the oxygen consumption in the water body, reduce the dissolved oxygen in the water body, and hinder the growth of fish. [0005] 3) Snails are the intermediate parasites of many fish diseases, such as the digenetic trematode cercariae and redidia of fish helminthosis. [0006] In addition, the mass reproduction of snails can easily cause schistosomiasis infection in humans and animals. Oncomelania is th...

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Problems solved by technology

Wherein although sodium pentachlorophenate is cheap, it is all poisonous to people, poultry, livestock and aquatic animals and plants because of it, and consumption is many, difficult to degrade, seriously pollute environment, most countries in the world have prohibited the use; It is in the stage of indoor experiment and small-scale trial, but the production process is complicated, the cost is high, and the price is expensive, so it is difficult to promote and use; currently the only species recommended by the World Health Organization and the Food and Agriculture Organization is niclosamide, which is not only effective for all snails For example, water snails include shellfish such as pointed snails, apple snails, stone snails, conchs, and river mussels, and dry snails include drill snails (snails), snails, etc., which have a strong ability to kill, and at the same time have a strong killing ability on various mollusk target animals. It has a strong killing effect, and has extremely low toxicity to higher animals such as humans and animals, and has no toxic effect on crops and other plants. It is easily degraded and decomposed into non-toxic substances by sunlight, etc., and has no cumulative residual toxicity

[0008] At present, most of the original drug of niclosamide relies on imports, with a price of more than 20,000 US dollars per ton. There are only a few manufacturers in my country that use imported original drug to produce wettable powder, and the production cost is relatively high.

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