Supercharge Your Innovation With Domain-Expert AI Agents!

A kind of preparation method of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline

A technology of dihydroquinoline and trimethyl is applied in the field of preparation of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline, and can solve the problems of unfavorable industrial production and process safety low, residual p-fluoroaniline, etc., to achieve the effect of being suitable for large-scale industrial production, increasing the number of products, and improving the yield

Active Publication Date: 2020-05-08
KINGCHEM LIAONING CHEMICAL CO LTD
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, fluoboric acid is highly toxic and irritating, resulting in low process safety; fluoboric acid is highly corrosive, requiring special corrosion-resistant production equipment; the conversion rate of raw materials is low, and there is a large amount of unreacted p-fluoroaniline remaining. Lead to low yield and low production capacity, which is not conducive to large-scale industrial production

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

[0044] Example 1 Preparation of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline

[0045] Add p-fluoroaniline (111 g, 1 mol) and toluene (44 g) into the glass reaction flask equipped with a water separator, and raise the temperature to 130-140°C. Add a solution made of acetone (203g, 3.5mol) and p-toluenesulfonic acid (33g) dropwise, and finish dropping in 24 hours. During the dropwise addition, keep at 120-130°C, and the water generated during the reaction is separated through a water separator. . After the dropwise addition, the conversion rate of p-fluoroaniline was 90% according to gas chromatography analysis. Distill the reaction liquid, first distill off the low boiling point substances, and then distill to 180°C under 1 mm Hg vacuum to obtain 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline (153g) , yield 80%.

Embodiment 2

[0046] Example 2 Preparation of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline

[0047] Add p-fluoroaniline (111 g, 1 mol) and xylene (55 g) into a glass reaction flask equipped with a water separator, and heat up to 140-150° C. Add dropwise a solution made of acetone (262g, 4.5mol) and p-toluenesulfonic acid (25g), and finish dropping in 20 hours. During the dropping process, keep 130-140°C, and the water generated during the reaction is separated through a water separator. . After the dropwise addition, the conversion rate of p-fluoroaniline was 92% according to gas chromatography analysis. Distill the reaction liquid, first distill off the low boiling point substances, and then distill to 180°C under 1 mm Hg vacuum to obtain 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline (155g) , yield 81%.

Embodiment 3

[0048] Example 3 Preparation of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline

[0049] Add p-fluoroaniline (111 g, 1 mol) and xylene (55 g) into a glass reaction flask equipped with a water separator, and heat up to 140-150° C. Acetone (232g, 4mol) was added dropwise, and the drop was completed in 40 hours. During this period, p-toluenesulfonic acid (33g) was divided into ten parts on average, and one part was added every 4 hours. The water produced during the reaction is separated through the water separator. After the dropwise addition, the conversion rate of p-fluoroaniline was 96% according to gas chromatography analysis. Distill the reaction liquid, first distill off low boiling point substances, and then distill to 180°C under 1 mm Hg vacuum to obtain 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline (161g) , yield 84%.

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 provides a preparation method of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline. The preparation method comprises the following steps: taking para-fluoroaniline and acetone as raw materials; heating and carrying out cyclization reaction to generate 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline under the catalysis action of p-toluene sulfonic acid, wherein the weight ratio of the para-fluoroaniline to the p-toluene sulfonic acid is 1 to (0.01 to 2); removing water generated in the reaction process by adopting a mode of direct distillation or azeotropic distillation with an inert solvent. The preparation method has the advantages of low cost, high conversion rate of raw materials, high yield, safety, environmental protection, no need of any special equipment, easiness in purification and suitability for large-scale industrial production.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a preparation method of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline. Background technique [0002] 6-Fluoro-2,2,4-trimethyl-1,2-dihydroquinoline is an important substituted 1,2-dihydroquinoline compound, which has good application prospects in the fields of medicine and pesticides. Regarding the preparation method of 6-fluoro-2,2,4-trimethyl-1,2-dihydroquinoline, p-fluoroaniline and acetone are mostly used as raw materials, and 6-fluoro-2,2-dihydroquinoline is produced under the action of a catalyst. ,4-Trimethyl-1,2-dihydroquinoline. E.g: [0003] Document Novel facile synthesis of 2,2,4substituted 1,2-dihydroquinolines via a modified Skraup reaction (Tetrahedron Letters, 43(21), 3907-3910; 2002) discloses the use of p-fluoroaniline and acetone as raw materials, in trifluoromethane Under the action of scandium sulfonate catalyst, 6-fluoro-2,2,4-trimethyl-1,2-dihy...

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 Patents(China)
IPC IPC(8): C07D215/18
CPCC07D215/18
Inventor 李振威赵阳刘树宽刘海盛王栋姜志鹏宋桐集李德刚
Owner KINGCHEM LIAONING CHEMICAL CO LTD
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

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

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com