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Recycling method and application of L-methyldopa intermediate

A kind of technology of methyldopa intermediate and L-methyldopa, which is applied in the field of recovery of L-methyldopa intermediate, can solve problems such as no literature report, and achieves strong operability, easy process implementation and high efficiency. Good production and controllability

Active Publication Date: 2016-08-31
ZHEJIANG WILD WIND PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0021] In the present technology, although the preparation method of L-3-(3,4-dimethoxyphenyl)-2-methylalanine hydrochloride and L-methyldopa has more patent documents and papers Public reports have been carried out, but about recovering and synthesizing L-methyldopa from the mother liquor synthesized from L-3-(3,4-dimethoxyphenyl)-2-methylalanine hydrochloride, no other There are literature reports

Method used

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  • Recycling method and application of L-methyldopa intermediate
  • Recycling method and application of L-methyldopa intermediate
  • Recycling method and application of L-methyldopa intermediate

Examples

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preparation example

[0039] 1) Synthesis of DL-aminopropionitrile

[0040] Dissolve 154.5g (3.15mol) of 96% to 98% sodium cyanide and 163g (3.05mol) of ammonium chloride in 2200ml (26.8mol) of 12.2mol / L ammonia solution at room temperature, heat to 55°C and stir rapidly Quickly add 582.6g (3mol) veratrone, stir for another 1h, then cool down to below 20°C within 1.5h, fine particle products start to precipitate, keep stirring for 2h, cool down to 0°C, filter with suction, the filtrate is DL-amino The mother liquor of propionitrile synthesis, the filter cake was washed with 800ml of ice water, and dried to obtain 618.42g (2.81mol) of DL-aminopropionitrile, with a molar yield of 93.7%, and a melting point of 85°C to 87°C. The obtained DL-aminopropionitrile could be Purification directly resolved.

[0041] 2) Resolution of DL-aminopropionitrile

[0042] 125g of D-tartaric acid (0.83mol) was dissolved in 500ml of water, and the pH was adjusted to 8 with sodium hydroxide to obtain a D-tartrate disodi...

Embodiment 1

[0051] Get the mother liquor 262.5ml that step 4) obtains (containing 3-(3,4-dimethoxyphenyl)-2-methylalanine hydrochloride 10.67g), add ammonium sulfate 32.8g (volume weight ratio mother liquor : Salt = 8: 1), carry out 60 ℃, vacuum-0.08mpa decompression distillation, distill 168ml of water (COD: 798mg / L), a small amount of crystals precipitate, cool down to 0 ℃, filter, add 10ml of ice water (0 ℃ ) was washed to obtain a solid, which was dried to obtain 9.7g, the recovery rate of 3-(3,4-dimethoxyphenyl)-2-methylalanine hydrochloride was 90.9%, and the HPLC purity was 98.3%; the mother liquor continued to distill , distilled 30ml of water (COD: 839mg / L), a large number of crystals precipitated, cooled to 0°C, filtered to obtain a solid, dried to obtain 44.1g, containing COD: 1.2g, mother liquor 14ml, COD: 40936mg / L.

Embodiment 2

[0053] Get the mother liquor 262.5ml that step 4) obtains (containing 3-(3,4-dimethoxyphenyl)-2-methylalanine hydrochloride 10.67g), add ammonium chloride 21.8g (volume weight ratio Mother liquor: salt = 12:1), carry out 60°C, vacuum-0.08mpa reduced-pressure distillation, distill 200ml of water (COD: 796mg / L), cool to 0°C, filter to obtain a solid, dry to obtain 10.1g, 3-( The recovery rate of 3,4-dimethoxyphenyl)-2-methylalanine hydrochloride is 95%, and the HPLC purity: 98.3%; the mother liquor continues to distill, and 34ml of water is distilled, a large number of crystals are precipitated, and the temperature is lowered to 0°C , filtered to obtain a solid, dried to obtain 34.2g, containing COD: 0.98g, mother liquor 10.8ml, COD: 23578mg / L

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Abstract

The invention discloses a recycling method and application of an L-methyldopa intermediate. The recycling method comprises the following steps: hydrolyzing L-3-(3,4-dimethoxy phenyl)-2-amino-2-methyl propionitrile hydrochloride by utilizing hydrochloric acid, and filtering to obtaining L-3-(3,4-dimethoxy phenyl)-2-methyl alanine hydrochloride and mother liquor, adding haloid salt or ammonium salt into the mother liquor, carrying out vacuum distillation, concentrating until volume is less than or equal to 1 / 3 of the original volume, and filtering, wherein a filter cake is namely the recycled 3-(3,4-dimethoxy phenyl)-2-methyl alanine hydrochloride solid. The recycling method disclosed by the invention has the advantages that L-methyldopa can be recycled from 3-(3,4-dimethoxy phenyl)-2-methyl alanine hydrochloride production waste liquor, and ammonia nitrogen and COD in wastewater can also be reduced, so that the recycling method accords with the green chemistry concept.

Description

technical field [0001] The invention belongs to the technical field of drug synthesis, and in particular relates to a recovery method and application of a L-methyldopa intermediate. Background technique [0002] Levomethyldopa is a receptor-blocking cardiovascular drug, which has a good effect on the treatment of moderate primary and secondary renal hypertension, and was listed as one of the national essential drugs by China in 1998. Pregnancy with hypertension is recommended for the treatment of drugs. Carbidopa is a dopa decarboxylate inhibitor. Because it cannot pass through the blood-brain barrier, it only inhibits the conversion of peripheral levodopa into dopamine, increasing the amount of levodopa entering the brain and reducing the adverse reactions caused by peripheral dopamine. , leading to elevated levels of levodopa in the circulation. Due to the increase of levodopa entering the brain, levodopa enters the center of the brain and converts it into dopamine, incr...

Claims

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Application Information

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IPC IPC(8): C07C227/18C07C229/36C07C227/34C07C227/16C07B57/00
CPCC07B57/00C07B2200/07C07C227/16C07C227/18C07C227/34C07C229/36
Inventor 周卫国张拥军曹铭红唐国军朱勇华胡伟强吴国英
Owner ZHEJIANG WILD WIND PHARMA
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