2results about How to "High molar yield" patented technology

This invention relates to the field of organic compound preparation technology, specifically a method for preparing 11-triglycerides of carbonate via low-temperature acylation. This method uses glycerol and undecanoyl chloride as raw materials, employing a synergistic system of a "composite acid-binding agent + Lewis acid catalyst," and combines in-situ dehydration technology and a stepwise heating strategy in a dual-solvent environment to achieve efficient synthesis. The specific steps include: under nitrogen protection, dissolving glycerol in a dichloromethane-toluene dual solvent, adding a composite acid-binding agent of pyridine and N,N-diisopropylethylamine, anhydrous zinc chloride catalyst, and 4A molecular sieve for in-situ dehydration; dropwise adding undecanoyl chloride at a low temperature of 5-10°C, followed by sequential heating to 30°C for 2-3 hours and then reacting at 50°C for 12-16 hours; and post-processing using a combined process of filtration-multi-stage extraction-membrane separation-column chromatography. This invention provides mild reaction conditions, effectively suppresses side reactions, produces high-purity products, increases molar yield, and reduces solvent toxicity and purification costs.

The invention provides a high-yield clean synthesis process of thiamethoxam, and relates to the technical field of pesticide fine chemical synthesis, and the process mainly comprises the following steps: Sp1, destroying crystal lattices of 3-methyl-4-nitroimido-perhydro-1, 3, 5-oxadiazine by using an ultrasonic cavitation technology, forming a low-temperature high-activity suspension in the presence of micronized inorganic base, and breaking through the bottleneck of solid-liquid mass transfer; the preparation method comprises the following steps: constructing an efficient nucleophilic system by using a quaternary ammonium salt and open-chain polyether composite catalyst; 2-chloro-5-chloromethylthiazole is introduced by adopting a two-way gradient feeding strategy combining low-temperature slow dropping and high-temperature fast dropping, reaction kinetics is accurately controlled, and decomposition of heat-sensitive raw materials is effectively inhibited; sp4, cleaning post-treatment is achieved through hot filtration desalination, mother liquor circulation and solvent recovery. The method effectively solves the problems of low yield and more impurities in the traditional high-temperature process, the molar yield of thiamethoxam can be stabilized at 96% or above, the product purity is high, the whole-process clean production is realized, and the method has remarkable industrial application value.