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A kind of preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride

A technology of methylaniline and methylphenylboronic acid is applied in the preparation of amino hydroxy compounds, the preparation of ethers by dehydration of hydroxyl-containing compounds, and the preparation of ethers. Broad application prospects, convenient process operation, and environment-friendly effects

Active Publication Date: 2021-05-11
ASTATECH CHENGDU BIOPHARM CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although this method has fewer process steps, the starting materials are not easy to synthesize, and the price is high, the reaction conditions are harsh, and the amount of three wastes is huge
Especially in the first step of bromination, the third step of nitrification, and the fourth step of passing through the autoclave, the risk factor of the reaction is relatively high, and the production discharge is large, which is easy to cause environmental pollution

Method used

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  • A kind of preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride
  • A kind of preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride
  • A kind of preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride

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Embodiment 1

[0030] A preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride, comprising the following steps:

[0031] S1. Preparation of 5-bromo-2-fluoro-3-methylphenylboronic acid

[0032] 5-Bromo-2-fluorotoluene (50g, 1.0eq), diisopropylamine (26.7g, 1eq) were sequentially added to a three-necked flask containing tetrahydrofuran (500g), and butyllithium ( 16.92g, 1eq) of cyclohexane (100g) solution, after the dropwise addition, the system was cooled to -65°C, the system was reacted for 2h, and then the tetrahydrofuran (100g) solution of isopropyl borate (49.77g, 1.3eq) was dropped Added to the reaction system, after the dropwise addition, continue to react for 3h. After the reaction was completed, water was slowly added to the reaction system, the organic phase was separated, the aqueous phase was extracted with methyl tert-butyl ether (500 g,), the organic phase was concentrated to dryness, and column chromatography (PE:MTBE=20:1) obtained 5-Bromo-2-fluoro-3-methylphe...

Embodiment 2

[0042] A preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride, comprising the following steps:

[0043] S1. Preparation of 5-bromo-2-fluoro-3-methylphenylboronic acid

[0044] Add 5-bromo-2-fluorotoluene (50g, 1.0eq) and diisopropylamine (40.15g, 1.5eq) to a three-necked flask containing tetrahydrofuran (500g) in sequence, and add butyllithium dropwise at 0°C (25.38g, 1.5eq) of cyclohexane (100g) solution, after the dropwise addition, the system was cooled to -65°C, and the system was reacted for 2h, then tetrahydrofuran (100g) of isopropyl borate (74.65g, 1.5eq) The solution was added dropwise to the reaction system, and after the dropwise addition was completed, the reaction was continued for 3 h. After the reaction was completed, water was slowly added to the reaction system, the organic phase was separated, the aqueous phase was extracted with methyl tert-butyl ether (500 g,), the organic phase was concentrated to dryness, and column chromatography (PE:MTB...

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Abstract

The invention discloses a preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride, which belongs to the field of organic synthesis. A preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride, the synthetic route is: a kind of 4-fluoro-3-methoxy-5-methylaniline hydrochloride of the present invention The preparation method of the salt uses cheap and easy-to-obtain 5-bromo-2-fluorotoluene as the starting material, and obtains 4-fluoro-3-methoxy-5-methylaniline hydrochloride through 5-step reaction, and the process is convenient to operate , low cost, safety, high total yield and environmental friendliness, suitable for industrial production, and has broad application prospects.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of 4-fluoro-3-methoxy-5-methylaniline hydrochloride. Background technique [0002] In 2012, Hui Li, Santa Clara, CA (US) and others used 2-fluoro-3-methylphenol as the starting material to obtain the product 4-fluoro-3-methoxy-5 through the following 4-step reaction - methylaniline hydrochloride (see US2012 / 28923; (2012); (A1 ) English). Although this method has fewer process steps, the starting material is not easy to synthesize, and the price is high, the reaction conditions are harsh, and the amount of three wastes is huge. Especially in the first step of bromination, the third step of nitrification, and the fourth step of passing through an autoclave, the risk factor of the reaction is relatively high, and the production discharge is large, which is easy to cause environmental pollution. [0003] Contents of the invention [0004] In vi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C217/84C07C213/02C07C213/08C07F5/02C07C39/27C07C37/60C07C43/225C07C41/16C07C41/09
CPCC07C37/60C07C41/09C07C41/16C07C213/02C07C213/08C07F5/025C07C39/27C07C43/225C07C217/84
Inventor 罗建业庄明晨李显军郭鹏
Owner ASTATECH CHENGDU BIOPHARM CORP