Improved method for producing prohexadione

An acid binding agent, diethyl maleate technology, applied in the preparation of carboxylate, organic chemistry and other directions, can solve the problems of high preparation cost and difficult post-processing

Inactive Publication Date: 2010-02-10
EAST CHINA UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is to provide a kind of 3,5-dioxo-4-propionylcyclohexanecarboxylic acid (calcium) preparation method with low preparation cost, which overcomes the high preparation cost and difficult aftertreatment in the prior art Defects

Method used

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  • Improved method for producing prohexadione
  • Improved method for producing prohexadione
  • Improved method for producing prohexadione

Examples

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preparation example Construction

[0015] The method for preparing compound (A) of the present invention comprises the following steps:

[0016] (1) compound (B) and acetone carry out addition reaction to obtain compound (C);

[0017] (2) Compound (C) is condensed by Claisen to obtain compound (D);

[0018] (3) compound (D) reacts with propionyl chloride to obtain compound (E);

[0019] (4) compound (E) is rearranged to obtain compound (F);

[0020] (5) Compound (F) is hydrolyzed to obtain compound (G);

[0021] (6) Compound (G) is salt-formed to obtain the target product [compound (A)].

[0022] Wherein: the reaction conditions of steps (1), (2) and (5) are similar to those of the prior art, please refer to EP 123001 for specific process conditions, and will not repeat them here.

[0023] Step (3) (acylation reaction): prior art (Robert.G.S.Brown, Li Yan, Michael.H.Beale, PeterHedden[J].Phytochemistry, 1998,679-687) adopts dichloromethane as reaction solvent, with 3 times the amount of triethylamine is re...

Embodiment

[0029] (1) Synthesis of 2-acetonyl diethyl succinate [compound (C)]:

[0030] The reaction formula is as follows:

[0031]

[0032] In diethyl maleate (34.4g, 0.2mol), acetone (95.3g, 1.64mol) and diethylamine (2.9g, 0.04mol) drop into 500ml autoclave, be heated to 150 ℃, and the pressure in the still is 1MPa, Insulated for 21 hours, cooled to room temperature, removed low boilers at normal pressure and then distilled under reduced pressure to collect fractions at 155°C-160°C (66Pa) to obtain 39.8g of light yellow liquid with a yield of 86.5%.

[0033] (2) Preparation of 3-hydroxy-5-ethoxycarbonylcyclohex-2-en-1-one [compound (D)]

[0034] The reaction formula is as follows:

[0035]

[0036] 40ml of absolute ethanol and sodium ethoxide (11ml, 0.056mol) were put into the reaction flask, and diethyl 2-acetonylbutyrate (12g, 0.052mol) was added dropwise. After the dropwise addition, it was heated to reflux for 4h. The reaction solution was cooled, concentrated and recla...

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Abstract

The invention discloses a making method of tranexamic acid [3,5-dioxo-4-propionyl cyclohexane carboxyl acid (calcium)], which comprises the following steps: adopting diethyl maleate as initial raw material; additioning diethyl maleate and acetone; obtaining the object through Claisen condensation, acylation, rearrangement, hydrolysis and salt precipitation; using the catalyst as N-(C1-C6) alkyl imidazole compound. The invention simplifies the operation and saves the preparing cost, which lays the groundwork for scale commerce of tranexamic acid.

Description

technical field [0001] The invention relates to a preparation method of prohexadione [3,5-dioxo-4-propionyl cyclohexanecarboxylic acid (calcium)]. Background technique [0002] Prohexadione (calcium 3-oxido-5-oxo-4-propionyl-cyclohexanecarboxylat), chemically named 3,5-dioxo-4-propionyl cyclohexanecarboxylic acid (calcium), is a plant growth regulator agent. Its structure is shown in formula (A). [0003] [0004] EP 123001 reports: Diethyl maleate is used as a starting material, firstly undergoes an addition reaction with acetone, and the resulting addition product undergoes successive Claisen condensation, acylation, rearrangement, hydrolysis and salt-forming reactions To obtain the target object, the synthetic route is as follows: [0005] [0006] In the prior art, the processes of "acylation", "rearrangement" and "salt formation" have defects such as high preparation cost and difficult post-treatment. For example, in the "acylation" process, the prior art uses...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C62/38C07C51/41
Inventor 蔡良珍陶晓春马振堂孙忠华俞永标梅含辉
Owner EAST CHINA UNIV OF SCI & TECH
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