Process for preparing p-fluoro thiophenol

A technology for p-fluorothiophenol and fluorobenzene is applied in the field of preparing p-fluorothiophenol by one-pot method, and can solve the problems of long process route, environmental discharge pollution, large equipment investment and the like

Inactive Publication Date: 2004-12-15
TIANJIN UNIV
View PDF1 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the dilution process after the two-pot method of sulfonyl chlorination can produce a large amount of waste acid, which is not fully utilized in production, causing environmental discharge pollution; the chlorosulfonation reaction is carried out in a reactor, and after the chlorosulfonation is completed, the Pour the reaction mixture into ice water to dilute and precipitate, filter, then add the prepared sulfuric acid and p-fluorobenzenesulfonyl chloride filter cake in another reduction pot, and then add zinc powder for reduction
The method uses two reactors for chlorosulfonation and reduction, and a filter device is needed in the middle, so that the process route is long and the equipment investment is large; after chlorosulfonation, dilution and filtration discharge a large amount of waste acid, and the reduction stage consumes new sulfuric acid again. As a result, more wastewater is discharged and raw material consumption is greater

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1 In a 1000ml four-neck flask, add 280g (2.4mol) of chlorosulfonic acid, cool down to 5-10°C, add 29g (0.3mol) of fluorobenzene dropwise within 0.5h while cooling in an ice bath. After adding the fluorobenzene, remove the ice bath, keep the reaction at 10-20°C for 10 hours, then slowly raise the temperature to 60°C, keep the temperature for 0.5h, and the chlorosulfonation reaction ends.

[0016] Cool down to 10-15°C, slowly add 400g of crushed ice to dilute the sulfonation solution. The process of adding ice should be slow to prevent material flushing, and the temperature rises suddenly, and p-fluorobenzenesulfonyl chloride is easy to hydrolyze. After the above-mentioned diluted sulfonated solution is cooled to 10-20°C, slowly add 75g of zinc powder and keep the temperature at 10-20°C. After adding the zinc powder, keep it at 10-20°C for 2 hours, and then raise the temperature to 90°C. React for 2h, cool down and filter. The filter cake was washed with 500ml o...

Embodiment 2

[0018] Example 2 The conditions were the same as in Example 1 except that the diluted ice was increased from 400 g to 500 g. As a result, the yield of p-fluorothiophenol was 58%, and the purity was above 99%.

Embodiment 3

[0019] Example 3 Except that the diluted ice was reduced from 400 g to 300 g, other conditions were the same as in Example 1. As a result, the yield of p-fluorothiophenol was 50%, and the purity was above 99%.

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 one-pot process of preparing p-fluoro thiophenol includes the following steps: reaction between fluorobenzene and chlorosulfonic acid to produce p-fluorophenyl sulfuryl chloride, and adding icy water to lower the temperature to 0-40 deg.c; and adding zinc powder to the reactor for direct reduction in two stages, including the first stage at 0-50 deg.c for 1-4 hr and the second stage at 70-95 deg.c for 1-4 hr. The one-pot process completes the chrlorosulfonation and reduction in one reactor, needs no filtering separation, and has short technological process, less apparatus used, saving in material, less exhaust, low cost and easy industrial application.

Description

technical field [0001] The invention belongs to the production method of organic compounds, and particularly proposes a method for preparing p-fluorothiophenol in one pot. Background technique [0002] p-Fluorothiophenol is an important medicine, pesticide and polymer intermediate, and can also be used in the detection of chemiluminescent agents and the preparation of nonlinear optical materials. [0003] The existing synthetic method is basically to prepare p-fluorobenzenesulfonyl chloride by sulfonyl chlorination of fluorobenzene, add water to dilute, filter and separate p-fluorobenzenesulfonyl chloride, and then reduce p-fluorobenzenesulfonyl chloride to obtain p-fluorobenzenethiol . The sulfonyl chlorination agent is chlorosulfonic acid, and the reducing agent is sodium borohydride or zinc powder. The specific processes are: [0004] SO 2 Reaction method: in the US 5659088 technology disclosed by Bayer, p-fluorobenzenesulfonyl chloride...

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): C07C319/02C07C321/26
Inventor 张天永张友兰
Owner TIANJIN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap