Preparation of 2,4-dichloro-5-methoxy pyrimidine

A technology of methoxypyrimidine and methoxy, which is applied in the field of preparation of pesticide intermediates, can solve the problems of high price, non-seizure and high DAT price, and achieve the effect of simple synthesis and less harsh process conditions

Inactive Publication Date: 2009-07-22
JIANGSU HUAYI TECH
View PDF1 Cites 16 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example, the Chinese Invention Patent Authorization Announcement No. CN1172934C (ZL01811169.6) describes the use of 2,4-dichloro-5-methoxypyrimidine as a starting material, through hydrazination, ring closure and rearrangement to obtain DAT, but this patent does not Describe the synthesis method of 2,4-dich...

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
  • Preparation of 2,4-dichloro-5-methoxy pyrimidine
  • Preparation of 2,4-dichloro-5-methoxy pyrimidine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A To prepare 2,4-dihydroxy-5-methoxypyrimidine, put 222g (3.0mol) of ethyl formate and 81.0g (1.5mol) of solid sodium methylate into a thermometer, reflux condenser, dropping funnel and mechanical In a stirring 1000ml three-neck flask, stir at 30°C for 60 minutes, after cooling down to 20°C, add 104g (1mol) of methyl methoxyacetate to carry out condensation reaction at 20°C, and react for 240min after the dropwise addition to obtain the compound I, then add 300ml of methanol and 90g (1.5mol) of urea to compound I, reflux for 300min, concentrate to 1 / 2 volume, add 300ml of water to dissolve, cool to 15°C, neutralize with 6N hydrochloric acid to pH 3 , filtered, washed the filter cake twice with 100ml of water, and dried at 100°C for 8 hours to obtain 96.5g of compound II with a yield of 68% and a HPLC purity of 99.7%;

[0023] B To prepare 2,4-dichloro-5-methoxypyrimidine, add N, N-dimethyl 90.8g (0.75mol) of aniline and 230.2g (1.5mol) of phosphorus oxychloride, heated...

Embodiment 2

[0025] A Prepare 2,4-dihydroxy-5-methoxypyrimidine, put 444g (6.0mol) of ethyl formate and 56.7g (1.05mol) of solid sodium methylate into a thermometer, reflux condenser, dropping funnel and mechanical In a stirred 1000ml three-neck flask, stir at 30°C for 60 minutes, after cooling down to 20°C, add 104g (1mol) of methyl methoxyacetate to carry out condensation reaction at 0°C, and react for 400min after the dropwise addition to obtain the compound I, then add 300ml of methanol and 120g (2mol) of urea to compound I, reflux for 100min, concentrate to 1 / 2 volume, add 300ml of water to dissolve, cool to 15°C, neutralize with 2N sulfuric acid to a pH value of 3, Filter, wash the filter cake twice with 100ml of water, and dry at 100°C for 8 hours to obtain 93.6g of compound II with a yield of 66% and a purity of 99.7% by HPLC;

[0026] B prepares 2,4-dichloro-5-methoxypyrimidine, in the 500ml three-neck bottle that is equipped with thermometer, reflux condenser and mechanical stirr...

Embodiment 3

[0028] A To prepare 2,4-dihydroxy-5-methoxypyrimidine, put 296g (4.0mol) of ethyl formate and 108g (2mol) of solid sodium methylate into a tank equipped with a thermometer, reflux condenser, dropping funnel and mechanical stirring In a 1000ml three-neck flask, stir at 30°C for 60 minutes, cool down to 20°C, add 104g (1mol) of methyl methoxyacetate to carry out condensation reaction at 10°C, and react for 600min after the dropwise addition to obtain compound I. Then add 300ml of methanol and 240g (4mol) of urea to compound I, reflux for 500min, concentrate to 1 / 2 volume, add 300ml of water to dissolve, cool to 15°C, neutralize with acetic acid to pH 8, filter, and use The filter cake was washed twice with 100 ml of water, and dried at 100° C. for 8 hours to obtain 90.8 g of compound II with a yield of 64% and a purity of 99.7% by HPLC;

[0029] B To prepare 2,4-dichloro-5-methoxypyrimidine, add N, N-dimethyl Aniline 90.8g (0.75mol) and phosphorus oxychloride 153.5g (1mol), hea...

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
Melting pointaaaaaaaaaa
Login to view more

Abstract

The invention discloses a preparation method of 2, 4-dichloro-5-methoxypyrimidine, pertaining to the technical field of pesticide intermediate preparation. The method includes steps as follows: 2, 4-dihydroxy-5-methoxypyrimidine is prepared, and ethyl formate and solid sodium methoxide are added into a reaction device and stirred. After the temperature is lowered, methyl methoxyacetate is added for carrying out a condensation reaction to obtain a compound I, and then methanol and carbamide are added into the compound I and a refluxing reaction is carried out. A compound II is obtained after condensation, dissolution with water, cooling, neutralization, filtration and drying; the 2, 4-dichloro-5-methoxypyrimidine is prepared, and a chlorinating agent and an acid-binding agent are added into the compound II; and then a temperature reaction, dilution and filtration are carried out in sequence to obtain a crude product of the 2, 4-dichloro-5-methoxypyrimidine. The crude product is refined to obtain a pure product of the 2, 4-dichloro-5-methoxypyrimidine. The method has the advantages of easy availability of all raw materials, convenient synthesis, not exacting technological conditions, overall yield up to 57 percent to 67 percent, purity over 99.6 percent and applicability to industrialized production.

Description

technical field [0001] The invention belongs to the technical field of preparation of pesticide intermediates, and in particular relates to a preparation method of 2,4-dichloro-5-methoxypyrimidine. Background technique [0002] 2-Amino-5,8-dimethoxy[1,2,4]triazol[1,5-c]pyrimidine (DAT for short) is an important intermediate of a new herbicide with high efficiency, high efficiency and low toxicity. In the known preparation process of DAT, 2,4-dichloro-5-methoxypyrimidine needs to be used as a starting material. For example, the Chinese Invention Patent Authorization Announcement No. CN1172934C (ZL01811169.6) describes the use of 2,4-dichloro-5-methoxypyrimidine as a starting material, through hydrazination, ring closure and rearrangement to obtain DAT, but this patent does not Describe the synthesis method of 2,4-dichloro-5-methoxypyrimidine. At present, the domestic product (2,4-dichloro-5-methoxypyrimidine) mainly relies on imports, which is expensive, resulting in high DA...

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): C07D239/34
Inventor 王卉
Owner JIANGSU HUAYI TECH
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