Novel method for preparing 3-iodo-2-bromotoluene

A novel technology of bromotoluene, which is applied in the field of preparing 3-iodo-2 bromotoluene, can solve problems such as difficult centrifugation, troublesome post-reduction treatment, and potential safety hazards, and achieves wide and easy-to-obtain raw material sources, simple reagents, and easy operation. easy effect

Pending Publication Date: 2021-08-06
河北唯达生物医药产业技术研究有限公司
View PDF7 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the traditional preparation of 3-iodo-2-bromotoluene, iron powder is usually used for nitro reduction, so the post-reduction treatment is very troublesome, centrifugation is not easy, and a large amount of iron sludge will be generated, the amount of solid waste is relatively large, and there are potential safety hazards

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
  • Novel method for preparing 3-iodo-2-bromotoluene
  • Novel method for preparing 3-iodo-2-bromotoluene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Put 2-amino-3-nitrotoluene (21.8kg), water (130.9kg), and dioxane (67.4kg) into the reaction kettle, and the brown turbid liquid was heated to reflux, and 40% hydrogen was added dropwise under reflux Bromic acid (97.1kg), dropwise. Keep warm for 2 hours, cool down, cool down to 0-20°C, control at 0-20°C, add sodium nitrite solution (9.9kg / 87.3kg) dropwise, after dropping, keep warm for 2 hours, and configure potassium bromide, water, 40% at the same time Hydrobromic acid solution (23.7kg / 130.9kg / 97.1kg), lowered to 0-20°C for later use. Add dropwise to potassium bromide, water, in the system of 40% hydrobromic acid solution (a large amount of foams are generated in the process) after the insulation is completed. After the dropwise addition, keep warm at 0-5°C for 30-60 minutes, raise the temperature to 60°C for 30-60 minutes, and cool down to room temperature overnight. After TLC detects that there is no reactant, the reaction is complete. An appropriate amount of et...

Embodiment 2

[0034] Add 2-bromo-3-nitrotoluene (20.3kg), ethanol (203.0kg), and 5% palladium carbon (0.2kg) into the hydrogenation kettle. After the replacement is completed, control the pressure to 0.2-0.6MPa and the temperature to 45-55°C , hydrogenation reduction, sampling point plate detection, bromide disappears, hydrogenation is completed, cooled to room temperature, discharged, filtered, and desolvated under reduced pressure. A brown oil was obtained. Concentration under reduced pressure was carried out, and the temperature was controlled to be below 100° C. and evaporated to obtain 15.7 kg of pure product with a molar yield of 90%.

Embodiment 3

[0036] Add 2-bromo-3-aminotoluene (8.8kg), dioxane (26.2kg), and water (53.9kg) to reflux, add concentrated sulfuric acid (18.9kg) dropwise, and reflux for 1 to 2 hours. After reflux, cool down to 0-20°C and start adding sodium nitrite aqueous solution (3.3kg / 35.1kg) dropwise, and control the temperature between 0-20°C for about 1 hour. After dropping, stir at 0-20°C for 2 hours, and prepare potassium iodide aqueous solution (9.0 / 35.1 / kg). Concentrated sulfuric acid (18.9kg), after addition, was cooled to 0°C for use. Add the system dropwise to the reaction kettle with potassium iodide and concentrated sulfuric acid solution (control the temperature to 0-20°C, after about 1 hour, there will be more foam and more elemental iodine will be generated). After dropping, control the temperature at 0-20°C and stir for 2 hours, raise the temperature to 60°C for 2 hours, and cool down to room temperature for 2 hours (or overnight). The TLC raw material disappeared, and ethyl acetate w...

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 novel method for preparing 2-bromo-3-iodotoluene, and belongs to the field of chemical synthesis. The method specifically comprises the following steps: a, reacting 2-amino-3-nitrotoluene serving as a raw material with a hydrobromic acid reagent under the action of nitrite and alkali metal bromide to prepare 2-bromo-3-nitrotoluene; b, taking 2-bromo-3-nitrotoluene as a raw material, and preparing 2-bromo-3-aminotoluene through a hydrogenation reduction reaction under the condition of a palladium catalyst; and c, taking 2-bromo-3-aminotoluene as a raw material, and reacting under the action of nitrite, concentrated acid and alkali metal iodide to prepare the 3-iodo-2-bromotoluene.

Description

technical field [0001] The invention relates to a novel method for preparing 3-iodo-2 bromotoluene, which belongs to the technical field of chemical synthesis. Background technique [0002] As we all know, 3-iodo-2-bromotoluene is an important starting material for the synthesis of drugs and is widely used. In the traditional preparation of 3-iodo-2-bromotoluene, iron powder is usually used for nitro reduction, so the post-reduction treatment is very troublesome, centrifugation is not easy, and a large amount of iron sludge will be generated, the amount of solid waste is relatively large, and there are potential safety hazards . Contents of the invention [0003] (1) Solved technical problems [0004] In order to solve the above problems, the present invention intends to use 2-amino-3-nitrotoluene as a raw material, which is a commonly used reagent in chemical research and can be purchased in large quantities on the market. The route designed by the present invention ad...

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
Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/093C07C25/02C07C209/36C07C211/52C07C201/12C07C205/12
CPCC07C17/093C07C209/365C07C201/12C07C205/12C07C211/52C07C25/02
Inventor 瞿鑫马良
Owner 河北唯达生物医药产业技术研究有限公司
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