Improved process for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines

A technology of alkylpyridine and trifluoromethyl, applied in the field of preparation of 2-trifluoromethyl-5-alkylpyridine, can solve the problems of expensive and unstable

Active Publication Date: 2011-07-27
CORTEVA AGRISCIENCE LLC
View PDF7 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Unfortunately, 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones are relatively expensive and somewhat unstable, i.e. they are recommended to be stored under refrigeration

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
  • Improved process for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines
  • Improved process for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines
  • Improved process for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0088] Example 1: Preparation of 5-(1-methylthio)ethyl-2-(trifluoromethyl)pyridine

[0089]

[0090] Step 1. Preparation of 1-(3-methylthiobut-1-enyl)pyrrolidine

[0091]

[0092] A dry 5000 milliliter (mL) round bottom flask equipped with a mechanical stirrer, nitrogen inlet, addition funnel, and thermometer was charged with 591 g (4.27 moles) of anhydrous potassium carbonate pellets and 1428 mL (17.1 moles) of anhydrous pyrrolidine. The mixture was stirred under an atmosphere of nitrogen and cooled to 4°C with an ice bath before 1050 mL (8.9 moles) of 3-methyl-thiobutyraldehyde was added at a rate to keep the temperature below 10°C. Once the addition was complete, the cooling bath was removed and the reaction mixture was allowed to reach room temperature. The reaction contents were then filtered through a sintered glass filter funnel to remove solids, which were washed with 200 mL of anhydrous diethyl ether. The filtrate was concentrated in vacuo on a rotary evaporat...

Embodiment 2

[0096] Example 2: Alternative preparation of 5-(1-methylthio)ethyl-2-(trifluoromethyl)pyridine

[0097]

[0098]Charge 240 mL of toluene into a 500 mL jacketed reactor equipped with a circulating bath (containing Syltherm 800), mechanical stirring, dry ice / acetone condenser, and thermowell (with digital monitoring), and then add 43.3 g (0.6 mol) ethyl vinyl ether (EVE). The reaction mixture was cooled to 0 °C, and then a 1 / 4" Teflon line was placed subsurface in the reaction mixture. Trifluoroacetyl chloride (TFAC) was bubbled through the Teflon line for 1 hour. Fluoroethylene resin tube until 95.3 g (0.72 moles) of trifluoroacetyl chloride reagent has been added. During the addition of TFAC, the internal reaction temperature rose from 2°C to 6°C. The circulating bath temperature was then set at 20°C, The reaction mixture was warmed to the circulating bath set point and stirred for an additional 20 minutes. At this point, GC analysis showed the presence of about 4% (GC rel...

Embodiment 3

[0103] Example 3: Alternative preparation of 5-(1-methylthio)ethyl-2-(trifluoromethyl)pyridine

[0104]

[0105] A 2-liter three-neck round bottom flask equipped with mechanical stirring, nitrogen blanket, and temperature probe was charged with 152.0 g (1.10 moles) of solid potassium carbonate, followed by ~1 liter of toluene. To this mixture was added 71.1 g (1.00 moles) of pyrrolidine. The reaction mixture was cooled in an ice-water bath, then 118.20 g (1.00 mole) of 3-methylthiobutanal was added continuously via an addition funnel over 1 hour and 16 minutes. The rate of aldehyde addition was adjusted to keep the internal reaction temperature below ~10°C. The ice-water bath was removed and the reaction mixture was allowed to warm to ambient temperature and stirred for an additional 3 hours 30 minutes. At this point, GC analysis indicated the presence of ~0.4% (relative area) of starting 3-methylthiobutyraldehyde. The reaction mixture was suction filtered, and the filte...

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

PropertyMeasurementUnit
boiling pointaaaaaaaaaa
boiling pointaaaaaaaaaa
Login to view more

Abstract

2-Trifluoromethyl-5-(1-substituted)alkylpyridines are produced efficiently and in high yield from an alkyl vinyl ether and trifluoroacetyl chloride by cyclization.

Description

[0001] This application claims the benefit of US Provisional Application 61 / 077,189, filed July 1, 2008. technical field [0002] The present invention relates to an improved process for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines. Background technique [0003] 2-Trifluoromethyl-5-(1-alkylthio)alkylpyridines are useful intermediates for the preparation of some pesticides; see for example US Patent Publications 2005 / 0228027 and 2007 / 0203191. 4-alkane Oxy-1,1,1-trifluoro-3-buten-2-one is a useful intermediate for the preparation of 2-trifluoromethyl-5-(1-alkylthio)alkylpyridines; see , eg US Patent Publication 2008 / 0033180A1. Unfortunately, 4-alkoxy-1,1,1-trifluoro-3-buten-2-ones are relatively expensive and somewhat unstable, i.e. they are recommended to be stored under refrigeration . It would be desirable to have a general method for the preparation of 2-trifluoromethyl-5-(1-substituted)alkylpyridines, especially 2-trifluoromethyl-5-(1-alkylthio)...

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): C07D213/08C07D213/12C07D213/26C07D213/32
CPCC07D213/26C07D213/32C07D213/12C07D213/08A01N43/40
Inventor 道格拉斯.布兰德加里.罗思
Owner CORTEVA AGRISCIENCE LLC
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