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

Method for preparing 2-chloro-3-isothiocyanato-prop-1-ene

A technology of chloroallyl isothiocyanate and sodium thiocyanate, which is applied in the field of preparation of precursor 2-chloroallyl isothiocyanate, can solve the problems of cumbersome operation and low yield, and achieve Simplify the operation process, improve the yield and reduce the cost

Active Publication Date: 2012-02-29
ANHUI RES INST OF CHEM IND
View PDF5 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problems of low yield and cumbersome operation of the above-mentioned reaction system, the present invention provides a reaction system that enables nucleophilic substitution and rearrangement to proceed smoothly and thoroughly, and obtains 2-chloroallyl isothiocyanate in high yield. method

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
  • Method for preparing 2-chloro-3-isothiocyanato-prop-1-ene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Dissolve 97g of sodium thiocyanide, 0.5g of tetrabutylammonium chloride and 1g of potassium iodide in 600mL of water, add 111g of 2,3-dichloropropene, stir at 90°C for 20h, and detect the nucleophilicity of 2,3-dichloropropene by gas chromatography The substitution has been completely completed, and the rearrangement process has also been completed. At this time, the ratio of the rearrangement product to the substitution product in the system is 30:1. The reaction system is cooled to room temperature and left to stand. The system is in two phases, and the organic phase is separated out. The phase is bright yellow and transparent, and the organic phase is distilled under reduced pressure at a pressure of 40 mmHg, and the cuts at a temperature of 115 to 125 ° C are collected to obtain 122 g of 2-chloroallyl isothiocyanate in the form of a colorless transparent liquid. The total yield of the two steps of substitution reaction and rearrangement reaction is 91%. After the di...

Embodiment 2

[0029] Dissolve 97g of sodium thiocyanide and 1g of tetrabutylammonium chloride in 600mL of water, add 111g of 2,3-dichloropropene, stir at 90°C for 10 hours, gas chromatography detects that there is an obvious residue of 2,3-dichloropropene, continue heating and stirring To 24h, there is still a small amount of 2,3-dichloropropene, and the organic phase is cooled and separated. At this time, the organic phase is dark brown, and a small amount of 2,3-dichloropropene is removed by fractional distillation under reduced pressure. For product, 115-125 / 40mmHg, obtain 109g of colorless transparent liquid, yield 81%, after distillation finishes, there is a large amount of bitumen-like still bottom material residue, adds organic solvent and also is difficult to dissolve.

Embodiment 3

[0031] Dissolve 97g of sodium thiocyanide and 1g of potassium iodide in 600mL of water, add 111g of 2,3-dichloropropene, stir at 90°C for 24 hours, and detect by gas chromatography that 2,3-dichloropropene is obviously left.

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 relates to a method for preparing 2-chloro-3-isothiocyanato-prop-1-ene, which is to accomplish the nucleophilic substitution and rearrangement processes of 2,3-dichorproplene and thiocyanate in one step by using 2,3-dichorproplene as a raw material, sodium thiocyanate as a nucleophilic reagent and tetrabutylammonium chloride and potassium iodide as a catalyst. The catalyst used in the invention allows nucleophilic substitution to go smoothly and completely; while the nucleophilic substitution in the system goes smoothly and completely, the rearrangement is also accomplished; andthen, an organic phase is separated, the organic phase is distilled under reduced pressure, and the first distillate is collected. The total yield of the two steps is up to 91 percent. When the method provided by the invention is used, the operation process of the process is simplified considerably, the use of solvent is avoided completely, and the process yield is high; and the cost is reduced, and the production of waste water, water gas and water residue are reduced. Because the system contains little impurity, the yield and purity are not reduced obviously in the process of collecting product under reduced pressure even if the temperature rises to 130 DEG C and the pressure rises to 40mmHg.

Description

technical field [0001] The invention belongs to the technical field of preparation of nicotine insecticides, and in particular relates to a preparation method of precursor 2-chloroallyl isothiocyanate used for preparing nicotine insecticides. Background technique [0002] 2-Chloroallyl isothiocyanate is a precursor for the preparation of 2-chloro-5-chloromethylthiazole, and the latter is an important intermediate of nicotine insecticides. Its preparation method is mainly based on 2,3-di Allyl chloride is used as a raw material, and the nucleophilic substitution with thiocyanate is completed first, and then rearranged into 2-chloroallyl isothiocyanate: [0003] [0004] [0005] According to the reports of European Patent EP0446913 and Japanese Patent JP0256326, after the nucleophilic substitution reaction is completed in acetonitrile or ethanol, the inorganic salt is filtered out, the organic phase is separated by filtration, the solvent is distilled off under reduced ...

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): C07C331/22
Inventor 胡仁涛潘启玉
Owner ANHUI RES INST OF CHEM IND
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