Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Synthetic method for intermediate of benserazide hydrochloride

A technology of benserazide hydrochloride and a synthesis method, which are applied in directions such as hydrazone preparation and organic chemistry, can solve problems such as long production cycle and low yield, and achieve the effects of shortening production cycle, improving product yield and convenient handling.

Inactive Publication Date: 2014-07-30
ZHEJIANG NEXCHEM PHARMA
View PDF2 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] The present invention proposes a synthetic method of an intermediate of benserazide hydrochloride, which solves the problems of long production cycle and low yield in the prior art

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Synthetic method for intermediate of benserazide hydrochloride

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] A kind of synthetic method of the intermediate of benserazide hydrochloride, comprises the steps:

[0034] Step S1: Add 300ml of methanol to a 500ml four-neck flask, cool down to 15°C; add 55g of thionyl chloride dropwise to methanol, add 50g of DL-serine, and reflux for 4 hours, and place the reaction solution in a water bath at 45°C Concentrate to dryness under reduced pressure and set aside.

[0035] Step S2: Preparation of Serine Hydrazide:

[0036] Add 95g of hydrazine hydrate into a 500ml four-neck bottle, dissolve the serine methyl ester prepared in Test 1 with an appropriate amount of methanol, add the serine methyl ester dropwise to the hydrazine hydrate at 20°C, after the drop is complete, keep the reaction at 20°C for one hour, and cool to At room temperature, adjust the pH to 4.0-5.0 with concentrated hydrochloric acid, add 100ml of isopropanol, cool to 10°C, stir and crystallize for 3 hours; filter to obtain the product.

[0037] Step S3: Preparation of B...

Embodiment 2

[0041] A kind of synthetic method of the intermediate of benserazide hydrochloride, comprises the steps:

[0042] Step S1: Add 315ml of methanol into a 500ml four-neck flask, cool down to 10°C; add 60g of thionyl chloride dropwise into methanol, add 50g of DL-serine, reflux for 3 hours, and concentrate the reaction solution under reduced pressure to Dried and set aside.

[0043] Step S2: Preparation of Serine Hydrazide:

[0044] Add 100g of hydrazine hydrate into a 500ml four-necked bottle, dissolve the serine methyl ester prepared in step S1 with an appropriate amount of methanol, add the serine methyl ester dropwise to the hydrazine hydrate at 25°C, after the drop is complete, keep the reaction at 25°C for one hour, and cool to At room temperature, adjust the pH to 4.0-5.0 with concentrated hydrochloric acid, add 100ml of n-butanol, cool to 12°C, stir and crystallize for 3 hours; filter to obtain the product.

[0045] Step S3: Preparation of Benzylsilazone Hydrochloride: ...

Embodiment 3

[0049] A kind of synthetic method of the intermediate of benserazide hydrochloride, comprises the steps:

[0050] Step S1: Add 350ml of methanol to a 500ml four-necked flask, cool down to 5°C; add 65g of thionyl chloride dropwise to methanol, add 50g of DL-serine, reflux for 5 hours, and concentrate the reaction solution under reduced pressure to Dried and set aside.

[0051] Step S2: Preparation of Serine Hydrazide:

[0052] Add 105g of hydrazine hydrate into a 500ml four-necked bottle, dissolve the serine methyl ester prepared in step S1 with an appropriate amount of methanol, add the serine methyl ester dropwise to the hydrazine hydrate at 30°C, after the drop is complete, keep the reaction at 30°C for one hour, and cool to At room temperature, adjust the pH to 4.0-5.0 with concentrated hydrochloric acid, add 100ml of ethanol, cool to 15°C, stir and crystallize for 3 hours; filter to obtain the product.

[0053] Step S3: Preparation of Benzylsilazone Hydrochloride:

[00...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A provided synthetic method for an intermediate of benserazide hydrochloride comprises the following steps: step (a), taking DL-serine and thionyl chloride as initial raw materials, reacting to generate methyl-DL-serine hydrochloride, concentrating the reaction solution to dry, so as to obtain serine methyl ester, dissolving with methanol for usage in the reaction of step (b); step (b), adding serine methyl ester obtained in the step (a) into hydrazine hydrate, after reaction is finished, adding an alcohol, and adjusting ph to crystallize and further to obtain serine hydrazide; and step (c), reacting serine hydrazide obtained in the step (b) with 2,3,4-trihydroxybenzaldehyde in a methanol system, so as to obtain N-(DL-seryl)-2,3,4-trihydroxybenzaldehyde hydrazone. The preparation method disclosed by the invention is high in yield, low in cost, short in reaction period, environment-friendly and suitable for industrialized production.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a method for synthesizing an intermediate of benserazide hydrochloride. Background technique [0002] In the prior art, the synthetic method about the intermediate of benserazide hydrochloride is as follows: [0003] 1. Synthesis of serine methyl ester: [0004] The reaction of serine methyl ester is finished, and the existing technology is to concentrate the reaction solution, then add water and ethanol to crystallize [0005] Defects: long production cycle and low yield. [0006] 2. Synthesis of serine hydrazide: [0007] The existing technology directly dissolves serine methyl ester, then adds a large excess of hydrazine hydrate, heats the reaction, concentrates, and crystallizes the alcohol system. [0008] Defects: long production cycle and low yield. [0009] 3. Synthesis of Benzylsilazone Hydrochloride: [0010] The existing technology is that serine hydra...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C07C251/86C07C249/16
Inventor 熊庆生徐春柳黄利溢滕燕娟
Owner ZHEJIANG NEXCHEM PHARMA
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com