Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation method of thiamethoxam

A technology of thiamethoxam and oxadiazine, which is applied in the field of drug synthesis, can solve the problems of methanol solvent recrystallization, low content, and large amount of waste water, and achieve the effects of improving purity, stabilizing the reaction system, and promoting the reaction

Inactive Publication Date: 2018-02-16
江苏绿叶农化有限公司
View PDF4 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The synthetic method of thiamethoxam mainly uses DMF as the solvent and potassium carbonate as the acid-binding agent at this stage. After the reaction is completed, 5 to 10 times the volume of water is added to precipitate the product, and then after centrifugal drying, recrystallization with methanol solvent, the content At 93 to 96%, the advantage of this method is that the process is simple, but the disadvantage is that methanol solvent recrystallization is required, the content is not high, and the amount of waste water is large. The waste water contains a small amount of thiamethoxam finished product, resulting in a low yield. Below 70%

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of thiamethoxam
  • Preparation method of thiamethoxam
  • Preparation method of thiamethoxam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] 1. Synthesis of compound II from compound I, the process is as follows:

[0024]

[0025] Add glacial acetic acid 140kg, sulfuric acid (concentration 98%) 20kg, water 40kg successively in reactor and start to stir, drop into paraformaldehyde 300kg then, be warming up to 40 ℃ after feeding, drop into methyl nitroguanidine 380kg, adjust temperature to 70 Insulate at ℃ for 10 hours, cool down to 40°C at the end of the heat preservation, add dropwise saturated sodium bicarbonate solution to adjust the pH to 6.8, add 200kg of water after the end, stir, cool down to 0°C, discharge, suction filter, centrifuge, and shake to obtain 3-methyl -4-nitroimine-1,3,5-oxadiazine, the content is more than 98%, and the yield is 82%. The filtrate and centrifuged mother liquor go to the three wastes for treatment. 1 HNMR (CDCl 3 ): δ9.74 (bs, NH), 5.00 (d, 2H, oxadiazine-6-H), 4.85 (s, 2H, oxadiazine-2-H), 3.01 (s, 3H, CH 3 ).

[0026] 2. Synthesis of compound III from compound II, t...

Embodiment 2

[0030] 1. Synthesis of compound II from compound I, the process is as follows:

[0031]

[0032] Add glacial acetic acid 120kg, sulfuric acid (concentration 98%) 20kg, water 50kg successively in reactor and start to stir, then drop into paraformaldehyde 300kg, be warming up to 43 ℃ after feeding, drop into methyl nitroguanidine 300kg, adjust temperature to 75 Insulate at ℃ for 12 hours, cool down to 46°C at the end of the insulation, add dropwise saturated sodium bicarbonate solution to adjust the pH to 7.0, add 200kg of water after the end, stir, cool down to 0°C, discharge, suction filter, centrifuge, and shake to obtain 3-methyl -4-nitroimine-1,3,5-oxadiazine, the content is more than 98%, and the yield is 83%. The filtrate and centrifuged mother liquor go to the three wastes for treatment. 1 HNMR (CDCl 3 ): δ9.75 (bs, NH), 5.00 (d, 2H, oxadiazine-6-H), 4.88 (s, 2H, oxadiazine-2-H), 3.02 (s, 3H, CH 3 ).

[0033] 2. Synthesis of compound III from compound II, the proc...

Embodiment 3

[0037] 1. Synthesis of compound II from compound I, the process is as follows:

[0038]

[0039]Add glacial acetic acid 140kg, sulfuric acid (concentration 98%) 20kg, water 60kg successively in reactor and start to stir, drop into paraformaldehyde 300kg then, be warming up to 46 ℃ after feeding, drop into methyl nitroguanidine 380kg, adjust temperature to 78 Keep warm at ℃ for 14 hours, cool down to 45°C after the heat preservation, add dropwise saturated sodium bicarbonate solution to adjust the pH to 6.6, add 220kg of water after the end, stir, cool down to 2°C, discharge, suction filter, centrifuge, and shake to obtain 3-methyl -4-nitroimine-1,3,5-oxadiazine, the content is more than 98%, and the yield is 85%. The filtrate and centrifuged mother liquor go to the three wastes for treatment. 1 HNMR (CDCl 3 ): δ9.75 (bs, NH), 5.02 (d, 2H, oxadiazine-6-H), 4.86 (s, 2H, oxadiazine-2-H), 3.01 (s, 3H, CH 3 ).

[0040] 2. Synthesis of compound III from compound II, the proce...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a preparation method of thiamethoxam. The preparation method of the thiamethoxam comprises the following steps: taking methylnitroguanidine as a starting material, preparing 3-methyl-4-nitroimine-1,3,5-oxadiazine (compound II), and then preparing the thiamethoxam. The method provided by the invention is simple in process, the finally synthesized thiamethoxam does not need recrystallization, the content of the final product is up to 98% or above, and the yield reaches 84% or above.

Description

technical field [0001] The invention belongs to the field of drug synthesis, and in particular relates to a preparation method of thiamethoxam. Background technique [0002] Thiamethoxam (thiamethxoam) is a neonicotinoid insecticide successfully developed by Ciba-Geigy (now Syngenta) in 1997, which can selectively inhibit the nicotinic acid acetylcholinesterase receptor in the central nervous system of insects. , and then block the normal conduction of the central nervous system of insects, causing paralysis and death of pests. [0003] Thiamethoxam is mainly used as a foliar insecticide and seed treatment agent. It entered the New Zealand market in 1997 and is used for corn seed treatment. Launched in Argentina and Brazil in 1998, it is used for potato, tobacco, peach, cotton, soybean, corn, rice and other crops. Launched in South Africa in 1999, it is used for corn and wheat. It was registered and listed in Canada and the United States in 2000, and listed in Australia i...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C07D417/06
CPCC07D417/06
Inventor 彭荣贵乐成芝裴建华陈标
Owner 江苏绿叶农化有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com