Teriflunomide Impurities

English synonyms：

2-Cyanoacetic Acid;aceticacid,Cyano-;acide Cyanacetique;cyanoacetic;cyanoacetice Acid;malonic Mononitrile;malonic Acid Mononitrile;cyanocetic Acid

Cyanoacetic acid Chemical Properties

Introduction:

Cyanoacetic Acid Is an Important Type of Organic Synthetic Raw Material and Pharmaceutical and Dye Intermediates. It Is Used to Manufacture Adhesives, Vitamins, Etc. Its Derivatives, Such as Methyl Cyanoacetate and Ethyl Cyanoacetate, Are Widely Used in Medicine, Agriculture, New Materials, Etc. Important Applications, Therefore the Demand for High Purity Cyanoacetic Acid Is Increasing Day by Day.

Preparation:

A Preparation Method of Cyanoacetic Acid, Characterized by Comprising the Following Steps:

(1) Cyanation Reaction: Carry out Cyanation Reaction Between Sodium Chloroacetate and Sodium Cyanide to Generate Sodium Cyanoacetate Aqueous Solution;

(2) Acidification Reaction: Add Hydrochloric Acid to the Sodium Cyanoacetate Aqueous Solution Described in Step (1) for Acidification to Obtain a Mixed Solution of Cyanoacetic Acid and Sodium Chloride;

(3) Dehydration Under Reduced Pressure: The Mixed Solution of Cyanoacetic Acid and Sodium Chloride in Step (2) Is Evaporated and Dehydrated Under Negative Pressure, The Sodium Chloride Is Precipitated, And the Sodium Chloride Is Filtration; 

(4) Melt Crystallization: Use a Crystallizer, Preheat the Crystallizer to Make the Cyanoacetic Acid in Step (3) in a Molten State, And Heat the Cyanoacetic Acid in a Molten State at 10°c to 20°c/ H. Cool the Temperature to the Crystallization Temperature of the Cyanoacetic Acid to Crystallize the Cyanoacetic Acid; Separate the Solid-Liquid Product of the Crystallized Product, Use the Solid Phase Product as the Raw Material, And Recover the Residual Liquid; Then Use 2°c to 6°c/ The Crystallizer Is Heated to 40-45°c at a Speed of H and Kept Warm to Partially Melt the Solid Phase Product, And the Discharged Uncrystallized Mother Liquor Is Used as the Raw Material for Re-Melting and Crystallization;

The Crystals Obtained by Placing Them in the Crystallizer Are Heated Until They Are Completely Melted, And Finally the Cyanoacetic Acid Crystals Are Obtained. The Advantage of This Method Is That It Effectively Improves the Purity of Cyanoacetic Acid Through the Processes of Cyanation, Acidification, Dehydration Under Reduced Pressure and Crystallization, And There Is No Need to Add Solvents During the Melting and Crystallization Purification Process, Thus Avoiding Solvent Contamination of the Product and Reducing Solvent Costs. The Recycling Process Saves Equipment Investment, And the Purified Product Has High Purity and High Yield. The Product Purity Reaches 99% and the Yield Reaches 90%.

Chemical properties:

White crystal, hygroscopic. Soluble in water, ethanol and ether, slightly soluble in benzene and chloroform.

Use

Usage: Used in the pharmaceutical industry to prepare vitamin B6, carboline, medical adhesives, etc., and also used in the synthesis of the pesticide cremoxanil.

Usage: Cyanoacetic acid is an intermediate of the fungicides Daphne and Crimoxanil, and an intermediate of the pharmaceutical caffeine.

Usage: Organic synthesis intermediate, mainly used in the synthesis of cyanoacetate esters, and also used in the production of alpha methyl cyanoacrylate and n-butyl ester (medical adhesives), vitamin B6, caffeine, barbiturates, etc. Usage: It is an important intermediate in the production of medicines, dyes, and pesticides. It is mainly used for the synthesis of cyanoacetate esters. It is also used for the production of α-cyanomethyl acrylate and n-butyl ester (medical adhesives). It is used in the pharmaceutical industry for preparation. Vitamin B6, carbine, barbiturates, etc. It is also a large amount of raw material for the production of the pesticide and fungicide cymoxanil.

production method:

It is obtained by using chloroacetic acid, sodium carbonate, and sodium cyanide as raw materials, through neutralization, cyanidation, and acidification with hydrochloric acid. Add the sodium carbonate suspension to chloroacetic acid, and neutralize it through circulation below 45°C until pH=7.5-8. After the neutralization is completed, a sodium chloroacetate liquid is obtained. Add the neutralized liquid to the sodium cyanide solution and perform cyanidation at a temperature of 105-115°C. Keep the temperature for 2-3 minutes to obtain sodium cyanoacetate. Then cool the temperature to below 50°C and put the sodium cyanoacetate into a dehydration pot with hydrochloric acid. Acidification, and finally dehydration under reduced pressure, the finished product of cyanoacetic acid is obtained. Raw material consumption quota: chloroacetic acid (95%) 1240kg/t, sodium cyanide (96%) 710kg/t.

production method:

The preparation method is to dissolve chloroacetic acid in water, slowly add sodium carbonate suspension, keep it at 70°C for 1 hour, adjust the pH to 6.8-7, continue for 20 minutes, cool to 40°C, and add sodium cyanide and water to the reaction pot. Dissolve, stir, and heat to 40~45°C. Add the above sodium chloroacetate solution. The reaction will naturally heat up to 70°C. Control the heating rate. When it reaches 120°C, immediately cool down to below 40°C to obtain the sodium cyanoacetate solution. Transfer to acidification. , the solution is acidified by adding hydrochloric acid at 30°C, then heated and dehydrated under reduced pressure, and dehydrated at 80°C and 14.6-21.3kPa pressure. When the water content in the solution is below 15%, cool to 50°C and add ethanol to filter out the chlorine generated by the reaction. of sodium, wash the filter cake with ethanol, combine the washing liquids, and evaporate the ethanol to obtain cyanoacetic acid. ClCH2COOH+Na2CO3→ClCH2COONa[NaCN]→NCCH2COONa[HCl]→NCCH2COOH+NaCl