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Preparation method of diethyl acetamidomalonate

A technology of diethyl acetamidomalonate and diethyl nitrosomalonate, applied in the field of medicinal chemistry, can solve the problems of high sodium acetate content, achieve high product content, low environmental pollution, and low production cost Effect

Inactive Publication Date: 2015-05-13
NANTONG NABAIYUAN CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] The object of the present invention is to provide a kind of preparation method of diethyl acetamido malonate, mainly solve the problem that the by-product sodium acetate produced by nitrosation in the existing industrial production technology contains a large amount of sodium nitrite and cannot be further processed

Method used

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  • Preparation method of diethyl acetamidomalonate

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Experimental program
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Effect test

Embodiment 1

[0021] Preparation of diethyl nitrosomalonate: Add 500g of chloroform, 140g of diethyl malonate, and 90g of sodium nitrite into a 1000ml four-necked flask, stir, cool down to 0°C, and Add 105g of acetic acid dropwise, heat up to 40-45°C after the dropwise addition, and keep stirring for 15 hours. After the reaction, filter out the sodium acetate generated by the reaction, rinse the filter cake with 200g of chloroform, combine the filtrates, concentrate and evaporate under reduced pressure organic solvent to obtain light yellow oil, which was directly used in the next reaction.

Embodiment 2

[0023] Preparation of diethyl acetamidomalonate: Take the diethyl nitrosomalonate obtained in the previous step, 178 g of acetic anhydride, and 525 g of acetic acid were successively added to a 1000 ml four-neck flask, slowly added 115 g of zinc powder under stirring, and added When zinc powder is used, the temperature of the feed liquid is controlled at 40-50°C. After the addition, the feed liquid is kept at 50-60°C for 2 hours. After the reaction, the zinc acetate produced by the reaction is filtered off while it is hot, and the filter cake is washed twice with 100g of hot acetic acid. , combine the filtrates, concentrate under reduced pressure to recover acetic acid, when a white solid precipitates out, the concentration is over, add 500g of purified water, heat to reflux, cool down to 0°C and stir for 10 hours after the solid dissolves, filter, wash with 100g of purified water, 60°C Vacuum drying gave 156 g of white crystalline powder with a yield of 82.1%. HPLC area norma...

Embodiment 3

[0025] Preparation of diethyl nitrosomalonate: Add 500g of dichloromethane, 140g of diethyl malonate, and 120g of sodium nitrite into a 1000ml four-neck flask, stir, cool down to 0°C, and Add 131g of acetic acid dropwise, heat up to 35-40°C after the dropwise addition, and keep stirring for 12 hours. After the reaction, filter out the sodium acetate generated by the reaction, rinse the filter cake with 200g of dichloromethane, combine the filtrates, concentrate and evaporate under reduced pressure organic solvent to obtain light yellow oil, which was directly used in the next reaction.

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Abstract

The invention discloses a preparation method of diethyl acetamidomalonate. The preparation method comprises the following steps: adding diethyl malonate and sodium nitrite to organic solvent, dropwise adding acetic acid at the temperature of 0-5 DEG C, carrying out heat preservation on a reaction system for 10-15 h at the temperature of 35-45 DEG C after adding, filtering solid after the reaction, recycling the organic solvent after filter liquor is concentrated to obtain nitroso-diethyl malonate, adding the nitroso-diethyl malonate to acetic acid and acetic anhydride, slowly adding zinc powder to carry out reductive acylation reaction, carrying out heat preservation on feed liquid for 2 h at the temperature of 50-60 DEG C after the zinc powder is added, filtering zinc acetate generated by the reaction after the reductive acylation reaction, recycling the acetic acid after the filter liquor is concentrated, carrying out recrystallization on concentrate by using purified water, and drying to obtain the diethyl acetamidomalonate. The preparation method is low in production cost, sodium nitrite can react completely, and the sodium nitrite is not contained in byproduct sodium acetate generated by nitrosation reaction, so that subsequent treatment is facilitated.

Description

technical field [0001] The invention belongs to the technical field of medicinal chemistry, and in particular relates to an industrial preparation method of diethyl acetamidomalonate. Background technique [0002] Diethyl acetamidomalonate (1) is an important intermediate in organic synthesis and an important intermediate in the anti-gastrointestinal ulcer drug Rebamipide; it is also used in the synthesis of desmethylclolincomycin hydrochloride (Lincomycin U-21729A), Lincomycin (Lincomycin), Amyllincomycin (Mirincarmycin) and Lincomycin Phosphate and other products; also used in the synthesis of α-amino acids, especially unnatural amino acids, such as Intermediates of tryptophan and pain mustard. Diethyl acetamidomalonate is currently in great demand, and large-scale industrial production has been realized in China in recent years. [0003] [0004] The report about diethyl acetamidomalonate at present, the synthetic method of bibliographical information mainly contains...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C231/02C07C233/47C07C51/41C07C53/10
Inventor 陆晓孙冬兵朱志平刘旭亮张海东葛玲丽
Owner NANTONG NABAIYUAN CHEM
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