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Method for purifying high-purity phenyl ethyl malonate

A technology of diethyl phenylmalonate and ethyl acetate is applied in the field of purification of high-purity diethyl phenylmalonate, which can solve the problems of difficulty in separation, affecting the quality of downstream drug production, and being difficult to remove.

Active Publication Date: 2010-01-27
南通森萱药业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Facts have proved: adopt the method for high-temperature distillation, because diethyl phenylmalonate is easily decomposed into diethyl phenyl ethyl malonate (III) at high temperature, and diethyl phenylmalonate and impurity (III) The boiling points are very close, and it is difficult to separate them by distillation
Thereby the method of underpressure distillation can only remove impurity (I), (II) with lower boiling point, and in the product after rectification, impurity (III) is not only difficult to remove, and its content is on the contrary the impurity (III) content in the crude product Increased by 3 to 4 times, finally the purity of the product is controlled at 97.0 to 98.0%, and the content of impurity (III) is generally between 0.5 and 3.0%, which greatly affects the quality of downstream pharmaceutical production

Method used

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  • Method for purifying high-purity phenyl ethyl malonate
  • Method for purifying high-purity phenyl ethyl malonate
  • Method for purifying high-purity phenyl ethyl malonate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] In the four-necked flask of 250ml, add phenylmalonate 80g (93.5%) impurity (III) content 0.51%, normal hexane 144.0g[phenylmalonate: normal hexane=1: 1.8 ( w / w)], activated carbon 4g, warming up to 30°C. After filtration, the filtrate was cooled to -10~-5°C, a large amount of white solids were precipitated, stirred for 45 minutes, and 77 g of crude product was obtained by filtration. The solvent was distilled off under reduced pressure at 60°C / 0.8 MPa to obtain 71.6 g of a colorless transparent liquid with a purity of 97.3%, impurity (III) content of 0.092%, and residual solvent of less than 0.1%. Yield 93.1%.

[0042] Add phenylmalonate 70g (97.3%) impurity (III) content 0.092% in the four-necked beaker of 250ml, normal hexane 126.0g[phenylmalonate: normal hexane=1: 1.8 ( w / w)], warming up to 30°C and stirring for 30 minutes. After cooling to -10°C to -5°C, a large amount of white solids precipitated, stirred for 30 minutes, and filtered to obtain 74g of crude produ...

Embodiment 2

[0044] In a 250ml four-necked flask, add 80g (94.1%) of diethyl phenylmalonate (94.1%) with an impurity (III) content of 0.45%, add petroleum ether (60-90°C) 128.0g [diethyl phenylmalonate : petroleum ether=1:1.6 (w / w)], activated carbon 4g. Raise the temperature to 30°C and stir for 30 minutes. filter. The filtrate was cooled to -10~-5°C, a large amount of white solid crystallized, stirred for 45 minutes, filtered, and 90.1 g of wet product was obtained. The solvent was distilled off under reduced pressure at 70°C / 0.6 MPa to obtain 72.5 g of a colorless transparent liquid with a purity of 97.7%, impurity (III) content of 0.075%, and residual solvent of less than 0.1%. Yield 94.1%.

[0045] In the four-necked flask of 250ml, add diethyl phenylmalonate 70g (97.7%), impurity (III) content 0.075%, sherwood oil 128g[diethyl phenylmalonate: sherwood oil=1: 1.6 ( w / w)], warming up to 30°C and stirring for 30 minutes. After cooling to -8°C to -5°C, a large amount of white solids...

Embodiment 3

[0047]Add 100g diethyl phenylmalonate (92.8%) in the 500ml four-necked flask, impurity (III) content 0.52%, add sherwood oil 160g, 8g ethyl acetate [diethyl phenylmalonate: solvent= 1:1.68 (w / w)], activated carbon 5g, stirred, mixed evenly, filtered. The filtrate was cooled to -10~-5°C, stirred for 45 minutes, and filtered to obtain 98g of wet product. The solvent was recovered under reduced pressure at 75°C / 0.5 MPa to obtain 88 g of a colorless transparent liquid with a purity of 98.6%, impurity (III) content of 0.062%, and residual solvent of 0.08%. Yield 93.5%.

[0048] Add 80g (98.6%) of diethyl phenylmalonate in a 500ml four-necked beaker, impurity (III) content of 0.062%, petroleum ether 128g, 6.4g ethyl acetate [diethyl phenylmalonate: mixed Solvent=1:1.68 (w / w)], heated up to 30°C, and stirred for 30 minutes. After cooling to -8°C to -5°C, a large amount of white solids precipitated, stirred for 30 minutes, and filtered to obtain 79g of crude product. The solvent w...

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Abstract

The invention relates to a method for purifying phenyl ethyl malonate, comprising the following steps: dissolving coarse phenyl ethyl malonate into a nonpolar solvent; decoloring by active carbon; filtering; mixing and crystallizing at the temperature of -10 DEG C to -5 DEG C; filtering to obtain a first filter cake; decompressing and recovering the solvent by the first filter cake to obtain colorless oil liquid as a fine product; dissolving the fine product into the nonpolar solvent; stirring and crystallizing at the temperature of -10 DEG C to -5 DEG C; filtering to obtain a second filter cake; decompressing the second cake to recover the solvent; and obtaining colorless transparent liquid as a phenyl ethyl malonate pure product. The purity of the phenyl ethyl malonate is greater than or equal to 99.5 percent, 2-phenyl-2-ethyl malonate impurities are less than 0.1 percent, and the total yield is greater than 90.0 percent.

Description

technical field [0001] The invention relates to a method for purifying high-purity diethyl phenylmalonate Background technique [0002] Diethyl phenylmalonate is an important pharmaceutical intermediate, its structural formula is as follows: [0003] [0004] Its properties are colorless transparent liquid at normal temperature, b.p.160℃ / 5mmHg, F.P.15℃. [0005] It is mainly used in [0006] (1) the application of cephalosporin drug, its reaction formula is as follows: [0007] [0008] (2) Application in other medicines. [0009] [0010] The main impurity of diethyl phenylmalonate in the synthesis process is ethyl 2-phenylbutyrate (I), ethyl phenylacetate (II), diethyl 2-phenyl-2-ethylmalonate (III), its structural formula is as follows: [0011] [0012] Among them, impurity (III) introduces "ethyl" at the α-position of diethyl phenylmalonate, which has a greater impact on the application of diethyl phenylmalonate in drug synthesis, and will import The i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C69/612C07C67/56C07C67/52
Inventor 童贞明马峰
Owner 南通森萱药业有限公司
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