Method for preparing 2-substituted benzoxazole compound

A compound and benzoxazole technology, applied in the synthesis field of benzoxazole compounds, can solve problems such as unfavorable environment, troublesome product purification, unfavorable post-processing, etc., and achieve the effects of high atom economy, convenient post-processing, and easy recovery

Inactive Publication Date: 2013-05-15
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The use of the oxidizing agent will introduce by-products in the reaction system, which is not conducive to post-processing, and will bring certain troubles to the purification of the product, and will produce by-products that are not conducive to the environment
The method for preparing 2-substituted benzoxazole compounds under the condition of no oxidant and hydrogen acceptor has not been reported in the literature so far

Method used

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  • Method for preparing 2-substituted benzoxazole compound
  • Method for preparing 2-substituted benzoxazole compound
  • Method for preparing 2-substituted benzoxazole compound

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] A method for preparing 2-substituted benzoxazole compounds, comprising the following steps:

[0034] (1) Mixing of raw materials

[0035] Using benzylamine and o-aminophenol as raw materials, metal palladium (palladium / carbon 53mg) as catalyst, and N,N-dimethylacetamide as solvent: 107mg (1mmol) of benzylamine and 109mg (1mmol) of o-aminophenol , palladium / carbon 53mg (0.05mmol), N,N-dimethylacetamide 2mL were successively added into a three-necked flask, stirred under a nitrogen atmosphere, and the raw materials were mixed with a catalyst and a solvent.

[0036] (2) Reaction

[0037] The mixture in step (1) is subjected to a chemical reaction, the reaction temperature is 120°C (oil bath temperature), and the reaction time is 28h; the chemical reaction formula is:

[0038] .

[0039] (3) Separation and extraction

[0040] After the reaction, the catalyst was filtered off, water and ethyl acetate were added to the filtrate, and the layers were extracted; the aqueou...

Embodiment 2

[0046] A method for preparing 2-substituted benzoxazole compounds, comprising the following steps:

[0047] (1) Mixing of raw materials: benzylamine 107mg (1mmol), o-aminophenol 109mg (1mmol), RuCl 3 Add 10mg (0.03mmol) and 2mL of N,N-dimethylformamide into a three-necked flask in sequence, stir under nitrogen atmosphere, and mix the raw materials with the catalyst and solvent.

[0048] (2) Reaction: The mixture in step (1) is subjected to a chemical reaction, the reaction temperature is 120°C (oil bath temperature), and the reaction time is 38h.

[0049] (3) Separation and extraction: After the reaction, cool down, add water and ethyl acetate to the reaction liquid, extract and separate layers, wash the water phase with ethyl acetate, and combine the organic phases.

[0050] (4) Drying and concentration: the organic phase obtained in step (3) was dried and concentrated with anhydrous sodium sulfate, and the target product——2-substituted benzoxazole compound (2-phenylbenzo ...

Embodiment 3~11

[0054] Under the same experimental conditions and operations as in Example 1, different metal palladium, platinum or ruthenium catalyzed the reaction of benzylamine compounds with o-aminophenol, see Examples 3-11 in Table 1 below.

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Abstract

The invention discloses a method for preparing a 2-substituted benzoxazole compound. According to the method, a benzylamine compound or a benzaldehyde compound or a benzyl alcohol compound, and o-toluidine-N-methyl-o-phenylenediamine, ortho-aminophenol and o-aminobenzenethiol serve as raw materials, metals palladium, platinum or ruthenium serves as a catalyst, and N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone serves as a solvent. The method comprises the following preparation steps: (1) mixing the raw materials; (2) reacting; (3) separating and extracting; and (4) drying and concentrating. An oxidant and a hydrogen acceptor are not required in the whole preparation process, and the used partial catalysts can be recycled. The method is high in atom economy, simple in aftertreatment and mild in reaction conditions and has a certain industrial application prospect.

Description

technical field [0001] The invention relates to a synthesis method of benzoxazole compounds widely used in the fields of medicine, pesticide, chemical industry, etc., specifically, a method for preparing 2-substituted benzoxazole compounds. technical background [0002] Benzoazole compounds (benzoxazole, benzothiazole, benzimidazole) are a very important class of heterocyclic compounds. The modification of benzoxazole derivatives is mainly to introduce different groups on the benzene ring. Or introduce different active groups on the 2-position, wherein the substituent at the 2-position has the greatest influence on its activity. 2-substituted benzoxazole compounds and their derivatives are widely used in the fields of medicine, pesticides, chemicals, materials, etc.: (as follows) A is the antihypertensive drug telmisartan; B is the drug azole for the treatment of diabetes Polrestat; C is a compound with anti-HIV activity; [0003] . [0004] The traditional preparation ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/57C07D277/66
Inventor 刘仁华金旭康廖能成刘雨潇
Owner EAST CHINA UNIV OF SCI & TECH
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