Synthesis method of benzocaine

A technology of benzocaine and a synthesis method, applied in the field of benzocaine synthesis, can solve the problems of high raw material price, cumbersome steps, unsuitable publicity and opening of student experiments, etc., and achieves the effects of improving teaching effect and improving experimental efficiency.

Inactive Publication Date: 2017-05-24
SHAANXI ALLIANCE LOGISTICS
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  • Abstract
  • Description
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AI Technical Summary

Problems solved by technology

In the above-mentioned method, method (1) step is loaded down with trivial details, and raw material price is high, is unsuitable to publicize and set up student's experiment; Salt, not easy to separate, not suitable for teaching activities

Method used

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Examples

Experimental program
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Embodiment Construction

[0010] Benzocaine synthetic method of the present invention, comprises the following steps:

[0011] The first step, the synthesis of p-nitrobenzoic acid, in 250mL three-necked flask, add the p-nitrotoluene of 0.05mol and be 5% tetramethylammonium bromide and 50mL distilled water relative to the molar fraction of p-nitrotoluene, Install a reflux condenser, a thermometer, and a stirrer, start stirring, and after the temperature rises to 90 degrees, add 0.125 mol KMnO in batches 4 , the reaction temperature is 90-95 degrees, and the reaction is stirred for 2.5 hours;

[0012] In the second step, cool the reaction liquid to room temperature, filter out the solid, wash the filter cake twice with hot water, combine the filtrates, acidify to pH=2-3, precipitate the solid, filter, wash the filter cake with cold water, and dry to obtain light yellow Crystal p-nitrobenzoic acid;

[0013] In the third step, the synthesis of ethyl p-nitrobenzoate, add 0.015mol p-nitrobenzoic acid, 25mL...

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Abstract

Relating to the field of chemical engineering, the invention in particular relates to a synthesis method of benzocaine. The method includes the steps of: synthesis of p-nitrobenzoic acid; synthesis of ethyl 4-nitrobenzoate; and synthesis of benzocaine. Through improvement of benzocaine synthetic experiment method, the invention specifically solves the problems of low yield, tedious reaction aftertreatment and the like in conventional preparation experiments, and the improved experimental operation method not only can achieve high yield preparation of benzocaine, enhance experimental efficiency, but also effectively improves the teaching effects of the experimental course, and is suitable for chemical experimental course teaching.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a synthesis method of benzocaine. Background technique [0002] Benzocaine (Benzocaine) is the common name of p-aminobenzoic acid ethyl ester, can be used as local anesthetic, and benzocaine is white crystalline powder, meets light color and turns yellow gradually, and the synthetic route of benzocaine can be summarized as The following two types: (1) use p-toluene gum as raw material to obtain benzocaine through acylation, oxidation, hydrolysis and esterification; (2) first reduce p-nitrobenzoic acid with ferrous sulfate to obtain p-amino Benzoic acid, and then esterified with absolute ethanol under acidic conditions to obtain benzocaine. In the above-mentioned method, method (1) step is loaded down with trivial details, and raw material price is high, is unsuitable to publicize and set up student's experiment; Salt, not easy to separate, not suitable for teaching activities. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C227/04C07C229/60
CPCC07C227/04C07C201/12
Inventor 刘秋丽
Owner SHAANXI ALLIANCE LOGISTICS
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