Synthesis method of tri(3,5,6-trichloropyridinyl)phosphite

Abstract

The invention relates to a method for synthesizing tri(3,5,6-trichloropyridinyl)phosphite, which comprises the following steps of: synthesizing 2-hydroxy-3,5,6-trichloropyridine under an acidic condition by using sodium 3,5,6-trichloropyridin-2-olate as a raw material, conducting drying and dehydrating, and controlling the reaction temperature of the product, a catalyst and phosphorus trichlorideto be 70-93 DEG C on the premise of micro-negative pressure to obtain the tri(3,5,6-trichloropyridinyl)phosphite. The specific synthetic route is shown in the specification. Micro negative pressure and the catalyst are introduced in the reaction process, so that the generation of diester and other side reactions is reduced, the reaction speed is increased, the reaction time is shortened, the purity and yield of a target product are improved, meanwhile, an organic alkali or organic ammonia acid-binding agent is not used, the production cost is reduced, and three wastes are reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, in particular to a method for synthesizing tris-(3,5,6-trichloropyridine) phosphite. Background technique [0002] At present, the fire safety situation is becoming more and more stringent. There are not many varieties of single additives with good plasticization, flame retardancy, oxidation resistance and stability. Most plastic additives only have one or two of the above functions, and multiple single additives are required. Auxiliaries are compounded and added, and the cost is relatively high. [0003] Tris-(3,5,6-trichloropyridine) phosphite has good plasticizing, flame retardant, oxidation resistance and stability. It can achieve the above properties when used alone, and has good compatibility, moderate price, and cost-effective High and widely used. The development and use of tris-(3,5,6-trichloropyridine) phosphite has great social and economic benefits. [0004] At present, ...

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Problems solved by technology

[0004] At present, the reaction of 3,5,6-trichloropyridin-2-alcohol sodium without acidification and dehydration with phosphorus trichloride to prepare tris-(3,5,6-trichloropyridine) phosphite has the following disadvantages : One, the reaction time is longer; Two, the sodium chloride produced in the reaction process is not easy to recycle, which is not conducive to wastewater treatment; Three, 3,5,6-trichloropyridin-2-alcohol sodium industrial products contain The amount of water is about 6%, it is easy to react with phosphorus trichloride, produce by-products and then affect the purity and quality of the target product, increase the amount of phosphorus trichloride and affect the purity of phosphorus trichloride when it is reused

In addition, most of the existing technologies use organic bases or organic ammonia as acid-binding agents, which increases the cost and the difficulty of wastewater treatment; the non-catalyst method takes a long time to react and easily produces more "diesters" and other by-products, resulting in lower purity of the target product, which needs to be purified and refined, which increases the cost and "three wastes"

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