Method for preparing lidocaine

A technology for lidocaine and dimethylaniline, applied in the field of preparation of lidocaine, to achieve the effects of high product purity, simple post-processing, and high yield

Pending Publication Date: 2020-03-31
BENGBU BBCA MEDICINE SCI DEV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems existing in the existing lidocaine production technology, the invention provides

Method used

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  • Method for preparing lidocaine
  • Method for preparing lidocaine
  • Method for preparing lidocaine

Examples

Experimental program
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Effect test

Embodiment 1

[0032] (1) Preparation of intermediate 2,6-dimethylaniline

[0033] Add 80g of 2,6-dimethylnitrobenzene, 5g of 5% Pd / C catalyst, and 160g of anhydrous methanol into a 500ml three-necked flask. After replacing with hydrogen, carry out hydrogenation reaction, filter after 20-25°C until the reaction is complete, recover Pd / C for recycling; the filtrate is distilled under reduced pressure, recover methanol for recycling, and obtain 59.2g of 2,6-dimethylaniline , yield 92.4%, HPLC purity 99.86%.

[0034] (2) Preparation of intermediate chloroacetyl-2,6-dimethylaniline

[0035] Weigh 48.4g of 2,6-dimethylaniline, 27.6g of potassium carbonate, and 275g of dichloromethane, and add them to the reaction flask in sequence, stir evenly, add 53.0g of chloroacetyl chloride dropwise, and react at room temperature for 1 hour. Dichloromethane was evaporated, washed with purified water and then dried to obtain 71.2 g of chloroacetyl-2,6-dimethylaniline with a yield of 91.0%.

[0036] (3) pre...

Embodiment 2

[0039] (1) Preparation of intermediate 2,6-dimethylaniline

[0040] Add 60g of 2,6-dimethylnitrobenzene, 4g of 5% Pd / C catalyst, and 115g of anhydrous methanol into a 500ml three-necked flask. After replacing with hydrogen, carry out hydrogenation reaction, filter after 25-30°C until the reaction is complete, recover Pd / C for recycling; the filtrate is distilled under reduced pressure, recover methanol for recycling, and obtain 43.2g of 2,6-dimethylaniline , yield 89.9%, HPLC purity 99.57%.

[0041] (2) Preparation of intermediate chloroacetyl-2,6-dimethylaniline

[0042] Weigh 36.3g of 2,6-dimethylaniline, 20.7g of potassium carbonate, and 205g of dichloromethane, and add them to the reaction flask in sequence. After stirring evenly, add 40.0g of chloroacetyl chloride dropwise, and react at room temperature for 1 hour. Dichloromethane was evaporated, washed with purified water and then dried to obtain 52.9 g of chloroacetyl-2,6-dimethylaniline with a yield of 90.3%.

[004...

Embodiment 3

[0046] (1) Preparation of intermediate 2,6-dimethylaniline

[0047] Add 40g of 2,6-dimethylnitrobenzene, 2g of 5% Pd / C catalyst, and 80g of anhydrous methanol into a 500ml three-necked flask. After replacing with hydrogen, carry out hydrogenation reaction, filter after the reaction is complete at 20-30°C, recover Pd / C for recycling; the filtrate is distilled under reduced pressure, recover methanol for recycling, and obtain 29.3g of 2,6-dimethylaniline , yield 91.4%, HPLC purity 99.22%.

[0048] (2) Preparation of intermediate chloroacetyl-2,6-dimethylaniline

[0049] Weigh 24.2g of 2,6-dimethylaniline, 13.8g of potassium carbonate, and 136g of dichloromethane, and add them to the reaction flask in sequence, stir well, then add 26.5g of chloroacetyl chloride dropwise, and react at room temperature for 0.5h. Dichloromethane was evaporated, washed with purified water and then dried to obtain 34.9 g of chloroacetyl-2,6-dimethylaniline with a yield of 89.3%.

[0050](3) prepara...

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Abstract

The invention discloses a method for preparing lidocaine. The method comprises the following steps of: (1) by using 2, 6-dimethylnitrobenzene as a raw material, Pd/C as a catalyst and methanol as a solvent, carrying out reduction reaction with hydrogen at normal temperature and normal pressure to obtain an intermediate 2, 6-dimethylaniline; (2) reacting the obtained intermediate 2, 6-dimethylaniline with chloroacetyl chloride in the presence of potassium carbonate, and taking dichloromethane as a solvent to prepare an intermediate chloroacetyl-2, 6-dimethylaniline; and (3) reacting the obtained intermediate chloroacetyl-2, 6-dimethylaniline with diethylamine, taking normal hexane as a solvent, performing refluxing until the reaction is complete, performing washing with water and cooling toobtain lidocaine. The method disclosed by the invention is simple and convenient in technological process, few in operation links and relatively high in lidocaine yield, and the prepared lidocaine isgood in purity which reaches 99.5% or above, so that the method has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the technical field of anesthetic synthesis, and in particular relates to a preparation method of lidocaine. Background technique [0002] Lidocaine is a local anesthetic commonly used in medical clinics. It was used to treat arrhythmia in 1963. It is currently a drug for preventing and treating acute myocardial infarction and various heart diseases complicated by rapid ventricular arrhythmia. Drug of choice for tachycardia and ventricular tremor. [0003] At present, the synthesis method of lidocaine still continues the traditional process method: first, m-xylene is used as raw material, nitrated by mixed acid, and then reduced by iron powder to obtain the intermediate 2,6-dimethylaniline, and then glacial acetic acid is used as solvent , sodium carbonate as a basic catalyst, reacting 2,6-dimethylaniline with chloroacetyl chloride to obtain the intermediate chloroacetyl-2,6-dimethylaniline, and the yield is about 67%; then ,...

Claims

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Application Information

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IPC IPC(8): C07C231/12C07C237/04
CPCC07C231/12C07C231/02C07C209/36C07C237/04C07C233/07C07C211/45
Inventor 林文龙李立标陈昀张瑾徐新
Owner BENGBU BBCA MEDICINE SCI DEV
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