Application overview of sodium trichloropyridinol
The full name of sodium triclopidol: 2-hydroxy-3.5.6-sodium triclopidol, which is synthesized as a low-toxic, broad-spectrum, low-residue organophosphorus insecticide and acaricide such as chlorpyrifos and chlorpyrifos-methyl. Main intermediates have been undergoing in-depth research, development and production at home and abroad. In recent years, with the accelerated construction of domestic chlorpyrifos equipment and the improvement and optimization of sodium chlorpyridine industrialization technology, the production and market prospects of sodium chlorpyridine are worth looking forward to.
Applications of sodium trichloropyridinol
Sodium chlorpyridine mainly produces the pesticide chlorpyrifos and is rarely used in other fields. It should be said that the market for chlorpyrifos is the market for sodium chlorpyrifos. Chlorpyrifos is an efficient, safe and broad-spectrum nitrogen-containing heterocyclic insecticide and acaricide. It has a high effect on almost all crops (wheat, rice, cotton, peanuts, vegetables, fruit trees, etc.) and all insect pests. It has insecticidal activity and has special effects on flying pests, underground pests and water pests. It can also be used for household hygiene control. This multi-purpose product is incomparable to other pesticides. According to national regulations, as of January 1, 2007, five highly toxic organophosphorus pesticides represented by methamidophos, 1605, monocrotophos, etc. are no longer allowed to be produced. From January 9, 2008, our country has allocated a large amount of funds to develop And industrialized replacement of five highly toxic pesticide varieties, and initially selected five high-efficiency, low-toxicity and low-residue organophosphorus pesticides represented by chlorpyrifos as the leading varieties of organophosphorus pesticides in the future.
Application and Preparation of Sodium Trichloropyridinol
Method 1: A one-pot method for synthesizing sodium trichloropyridinol, including the following steps:
1) One-step addition cyclization method: Add 180g of o-dichlorobenzene into the reaction vessel, then add 91g of trichloroacetyl chloride, and then add 27g of acrylonitrile and 0.4g of phase under stirring. Transfer catalyst PTC and 0.2g cuprous chloride of methoxyphenylboronic acid were added at 140°C for 24 hours;
2) Alkali pyridine dihydrochloride precipitation: Remove 180g of o-dichlorobenzene by desolvation, then add 200g of water and 50g of sodium hydroxide until the pH is about 12. Keep the temperature at 55°C, react for 8 hours, then raise the temperature to 140°C, react for 8 hours, cool down, filter and dry to obtain sodium triclopidinol solid.
Method 2: Industrial preparation method of sodium trichloropyridinol: The specific steps are as follows:
Step 1: Place 147.5kg of 98% trichloroacetaldehyde and 100kg of 98% dichloroethane in a 1m reaction kettle, add 100kg of 68% nitric acid dropwise under stirring, and finish the addition within 1 hour. Then dehydrate, and then distill out the solvent.
Step 2: Add 35kg of 99% industrial methanol, 10kg of 98% concentrated sulfuric acid and 2kg of 98% p-toluenesulfonic acid to the residue of step 1, and keep it at 80°C for 10 hours. After the insulation is completed, perform water treatment. The ester in the reactant was distilled, and after removing the fore distillate, 164.75kg of methyl trichloroacetate with a purity of 95% was obtained, and the yield was 90%.
Step 3: Put all the methyl trichloroacetate and 1kg of catalyst copper iodide obtained in step 2 into another 1m reaction kettle, and add 55kg of 99% acrylonitrile dropwise under stirring (approximately 2 hours to add (finished), the temperature rose to 150°C, and after the reflux was completed, the excess methyl trichloroacetate was distilled out to obtain 213.95kg of 2,2,4-trichloro-4-cyanobutyric acid methyl ester, and its content was determined to be 93 %, the yield is 96%.
Step 4: Place 213.95kg of 2,2,4-trichloro-4-cyanobutyric acid methyl ester and 212kg of phosphorus oxychloride and 1kg of water obtained in step 3 into a pressure kettle, and heat it to 160 ℃, after three hours, excess phosphorus oxychloride was evaporated, and 201.6kg of tetrachloropyridine was obtained, with a content of 93% and a yield of 94%.
Step five: Add 201.6kg of tetrachloropyridine obtained in step four and 230kg of 30% sodium hydroxide solution into the reaction kettle, raise the temperature to 92°C, react for 4 hours, then cool to room temperature, and filter to obtain target substance three Sodium chloropyridinol 180.4kg, purity 91%, yield 92%.
