Method for preparing tetracaine

A technology of n-butyraldehyde and n-butylamino, which is applied in the field of preparation of ester anesthetics, can solve the problems of difficult removal, low product purity and high production cost, reduces process time and energy consumption, and is beneficial to popularization and application , the effect of improving the purity of crude products

Active Publication Date: 2014-12-03
山东诚汇双达药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
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AI Technical Summary

Problems solved by technology

[0004] This method has the following disadvantages: the raw material adopts benzocaine and 1-bromobutane, the price is higher, and the production cost is high, which is unfavorable for popularization and application; dibutyl products are produced during alkylation, and this type of material is refined It is difficult to remove in the process, resulting in low product purity, the purity after one refinement is 94%-96%; in order to improve the purity, multiple refinements are generally used, and multiple refinements increase production costs, with a total yield of 45-55%. The yield is low, time-consuming and energy-consuming
[0007] This method will also produce dibutylated products, with many refining times and high production costs; and the alkylation yield is 50-55%, and the yield is low

Method used

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Embodiment Construction

[0013] One of the preferred specific implementations of the preparation method of the present invention, the specific steps are as follows: 1. 100ml of anhydrous methanol is added to the stirred reaction flask, 13.7g of p-aminobenzoic acid and 8g of n-butyraldehyde are added to the anhydrous methanol, and the temperature rises After reaching 50°C, heat and stir for 4 hours, then concentrate the methanol under reduced pressure to obtain 4-(n-butenylamino)benzoic acid; Add sodium oxide into the high-pressure reactor, then add 1.0g palladium carbon (10%), react under 1.5MPa hydrogen pressure and 90°C temperature, the material stays for 4 hours, release the pressure, and filter with suction, and the filtrate is adjusted to PH=2 with 10% hydrochloric acid , filtered with suction, and the resulting solid was dried at 50°C for 4 hours to obtain 4-(n-butylamino)benzoic acid; ③Add the 4-(n-butylamino)benzoic acid obtained in step ② into another reaction flask, Add 100ml of toluene as a...

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Abstract

The invention relates to a method for preparing tetracaine, which comprises the following steps: dissolving para aminobenzoic acid and n-butanal in absolute methanol, preserving temperature and mixing; then concentrating to remove methanol to obtain 4-(n-butene amino) benzoic acid; adding the 4-(n-butene amino) benzoic acid, water and sodium hydroxide into a high pressure reaction kettle; then adding palladium carbon (10%), and introducing hydrogen to reduce so as to obtain 4-(n-butyl amino) benzoic acid; adding the 4-(n-butyl amino) benzoic acid into another reaction flask, adding toluene and then adding N,N-dimethylethanolamine; refluxing and dividing water; and then purifying and drying to obtain tetracaine. The method provided by the invention has the advantages of low cost of raw materials, high yield and high purity and the like.

Description

technical field [0001] The invention relates to a method for preparing an ester anesthetic, specifically a method for preparing tetracaine. Background technique [0002] Tetracaine is a kind of local anesthetic, and it is one of the basic drugs in clinical application at home and abroad. The preparation method of existing tetracaine generally uses benzocaine as raw material, through hydrolysis, esterification, and alkylation obtains tetracaine, and reaction scheme is as follows: [0003] . [0004] This method has the following disadvantages: the raw material adopts benzocaine and 1-bromobutane, the price is higher, and the production cost is high, which is unfavorable for popularization and application; dibutyl products are produced during alkylation, and this type of material is refined It is difficult to remove in the process, resulting in low product purity, the purity after one refinement is 94%-96%; in order to improve the purity, multiple refinements are generally...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C229/60C07C227/18
Inventor 于东海刘战伟杨彦军孔江
Owner 山东诚汇双达药业有限公司
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