Name | Cyanoacetic acid |
Synonyms | Cyanoacetic cyanoacetate CYANOCETIC ACID Cyanoacetic acid Cyano Acetic Acid CYANOACETICE ACID Aceticacid,cyano- 2-cyanoacetic acid Acide cyanacetique 2-Cyanoacetic acid MALONIC MONONITRILE Methyl and Ethyl esters MALONIC ACID MONONITRILE |
CAS | 372-09-8 |
EINECS | 206-743-9 |
InChI | InChI=1/C3H3NO2/c4-2-1-3(5)6/h1H2,(H,5,6)/p-1 |
InChIKey | MLIREBYILWEBDM-UHFFFAOYSA-N |
Molecular Formula | C3H3NO2 |
Molar Mass | 85.06 |
Density | 1.3676 (rough estimate) |
Melting Point | 65 °C |
Boling Point | 108°C0.15mm Hg(lit.) |
Flash Point | 226°F |
Water Solubility | 1000 g/L (20 ºC) |
Solubility | H2O: soluble50mg/mL, clear, colorless to very faintly yellow |
Vapor Presure | 0.1 mm Hg ( 100 °C) |
Appearance | Adhering Crystalline Solid |
Color | White to light beige |
Merck | 14,2689 |
BRN | 506325 |
pKa | 2.45(at 25℃) |
PH | 1.6 (50g/l, H2O, 20℃) |
Storage Condition | Store below +30°C. |
Sensitive | Hygroscopic |
Refractive Index | 1.3764 (estimate) |
Physical and Chemical Properties | White crystals, hygroscopic. |
Use | Pharmaceutical industry for the preparation of vitamin B6, carbazine, medical adhesives, but also for the synthesis of pesticide |
Hazard Symbols | C - Corrosive |
Risk Codes | R22 - Harmful if swallowed R31 - Contact with acids liberates toxic gas R34 - Causes burns R52/53 - Harmful to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R20/22 - Harmful by inhalation and if swallowed. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S20 - When using, do not eat or drink. |
UN IDs | UN 3261 8/PG 2 |
WGK Germany | 2 |
RTECS | AG3675000 |
FLUKA BRAND F CODES | 3-10-21 |
TSCA | Yes |
HS Code | 2926 90 70 |
Hazard Class | 8 |
Packing Group | II |
Toxicity | LD50 orally in Rabbit: 1500 mg/kg LD50 dermal Rabbit > 2000 mg/kg |
White Crystal, hygroscopic. Melting Point: 66-68 °c. Boiling point 108 C (2kPa). Soluble in water, ethanol and ether, benzene-soluble and chloroform. Decomposition into carbon dioxide and acetonitrile at 160 °c. Malonic acid is produced after hydrolysis.
with chloroacetic acid, sodium carbonate, sodium cyanide as raw material, after neutralization, cyanide, hydrochloric acid acidification and derived. The sodium carbonate suspension is added to chloroacetic acid and neutralized to pH = 7.5-8 by circulation at a temperature below 45 ° C., and the sodium chloroacetate solution is obtained after neutralization. The neutralization solution is added to the sodium cyanide solution at a temperature of 105~115 ℃ for cyanidation, and the temperature is kept for 2~3 minutes to obtain sodium cyanoacetate, and then the temperature is cooled to below 50 ℃, sodium cyanoacetate was put into a dehydration pot and acidified with hydrochloric acid, and finally dewatered under reduced pressure to obtain a final cyanoacetic acid product.
This product is an organic synthesis intermediate, mainly used for the synthesis of cyanoacetic acid esters, in medicine for the synthesis of barbiturate and caffeine.
LogP | -0.76 |
NIST chemical information | Information provided by: webbook.nist.gov (external link) |
EPA chemical information | Information provided by: ofmpub.epa.gov (external link) |
introduction | cyanoacetic acid is a kind of important organic synthetic raw materials and pharmaceutical and dye intermediates, which are used to make adhesives, vitamins, etc. Its derivatives methyl cyanoacetate and ethyl cyanoacetate have important uses in medicine, agriculture, new materials, etc. Therefore, the demand for high-purity cyanoacetic acid is increasing day by day. |
preparation method | a preparation method of cyanoacetic acid, characterized by the following steps:(1) cyanidation reaction: cyanidation reaction of sodium chloroacetate and sodium cyanide to generate sodium cyanoacetate aqueous solution;(2) acidification reaction: adding hydrochloric acid to the sodium cyanoacetate aqueous solution in step (1) for acidification, get a mixed solution of cyanoacetic acid and sodium chloride;(3) Dehydration under reduced pressure: evaporate and dehydrate the mixed solution of cyanoacetic acid and sodium chloride in step (2) under the condition of negative pressure, precipitate the sodium chloride, and filter the sodium chloride;(4) Melt crystallization: use a crystallizer to preheat the crystallizer to make the cyanoacetic acid in step (3) in a molten state, the cyanacetic acid in the molten state is cooled to the crystallization temperature of the cyanacetic acid at 10°C ~ 20°C/h to crystallize the cyanacetic acid; the solid-liquid separation of the crystallized product, and the solid-phase product is used as raw material, Recover the residual liquid; then raise the temperature of the crystallizer to 40-45°C at a speed of 2°C ~ 6°C/h, keep the temperature, and partially melt the solid-phase product, the discharged uncrystallized mother liquor is used as the raw material for re-melting crystallization; the crystals obtained in the crystallizer are heated to full melting, and finally the cyanacetic acid crystals are obtained. The advantages of this method are: through the process of cyanidation, acidification, decompression dehydration and crystallization, the purity of cyanoacetic acid is effectively improved, and there is no need to add solvent in the process of melt crystallization and purification, which avoids the pollution of solvent to the product and reduces The solvent recovery process saves equipment investment, the purified product has high purity and high yield, the product purity reaches 99%, and the yield reaches 90%. |
Uses | The pharmaceutical industry is used to produce vitamin B6, carborphin, medical adhesives, etc., and is also used for the synthesis of pesticide cyanozine Cyanoacetic acid is an intermediate of fungicides rice blast and cyanozine, and is an intermediate of pharmaceutical caffeine. Organic synthesis intermediates, mainly used in the synthesis of cyanoacetate esters, also used in the production of alpha cyanoacrylate and n-butyl ester (medical adhesive), vitamin B6, caffeine, barbiturate, etc. It is an important intermediate for the production of medicines, dyes, and pesticides. It is mainly used for the synthesis of cyanoacetate esters, and is also used for the production of α-cyanoacrylate and n-butyl ester (medical adhesives). The pharmaceutical industry is used to prepare vitamin B6, Carphine, barbiturate, etc. It is also a large amount of raw material for the production of pesticide fungicide cyanozide. |
production method | using chloroacetic acid, sodium carbonate and sodium cyanide as raw materials, it is obtained by neutralization, cyanidation and hydrochloric acid acidification. The sodium carbonate suspension is added to chloroacetic acid, and it is recycled below 45 ℃ to pH = 7.5-8, and the sodium chloroacetate solution is obtained after neutralization. Add the neutralization solution to the sodium cyanide solution at a temperature of 105-115°C, perform cyanidation, keep the temperature for 2-3 minutes to obtain sodium cyanate, and then cool down to below 50°C, and put the sodium cyanate into the dehydration pot with hydrochloric acid Acidification, and finally dehydrate under reduced pressure to obtain the finished cyanacetic acid. Raw material consumption quota: chloroacetic acid (95%)1240 kg/t, sodium cyanide (96%)710 kg/t. the preparation method is to dissolve chloroacetic acid in water, slowly add sodium carbonate suspending agent, keep the temperature at 70 ℃ for 1h, adjust pH = 6.8~7, continue for 20min, cool down to 40 ℃, add sodium cyanide and water to the reaction pot to dissolve and stir, heat to 40~45 ℃, add the above sodium chloroacetate solution, naturally heat up to 70 ℃, control the heating rate, and immediately cool down when reaching 120 ℃, when it is reduced to below 40 ℃, a sodium cyanoacetate solution is obtained, which is transferred to acidification. The solution is acidified with hydrochloric acid at 30 ℃ and then heated under reduced pressure for dehydration. It is dehydrated at 80 ℃ and 14.6 ~ 21.3kPa pressure. When the water content in the solution is below 15% ℃, ethanol is added to the temperature to 50 ℃, the sodium chloride generated by the reaction is filtered out, the filter cake is washed with ethanol, the washing liquid is combined, and ethanol is distilled to obtain cyanoacetic acid. ClCH2COOH+Na2CO3→ClCH2COONa[NaCN]→NCCH2COONa[HCl]→NCCH2COOH+NaCl |
category | toxic substances |
toxicity classification | poisoning |
acute toxicity | oral administration-rat LD50:1500 mg/kg; Abdominal injection cavity-mouse LD50: 200 mg/kg |
flammability hazard characteristics | open flame is combustible; high heat emits toxic nitrogen oxides and cyanide gas |
storage and transportation characteristics | warehouse ventilation and low temperature drying; Store separately from oxidants, acids and food additives |
fire extinguishing agent | foam, mist water, carbon dioxide, sand; disable acid-base fire extinguishing agent |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |