Cyanoacetic acid

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Cyanoacetic acid
Cyanoacetic acid.svg
Identifiers
CAS number 372-09-8
PubChem 9740
ChemSpider 9357
Jmol-3D images Image 1
Properties
Molecular formula C3H3NO2
Molar mass 85.06 g/mol
Appearance colorless solid
Density 1.287 g/cm3
Melting point 69-70 ℃
Boiling point 108 ℃ (15 mm Hg)
Solubility in water 1000 g/L (20 ℃) in water
Hazards
Main hazards C:Corrosive; HazardClass:8
Flash point 107 °C (225 °F; 380 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Cyanoacetic acid is an organic compound. It is a white, hygroscopic solid. The compound contains two functional groups, a nitrile and a carboxylic acid. It is a precursor to cyanoacrylates, components of adhesives.[1]

Preparation and reactions[edit]

Cyanoacetic acid is prepared by treatment of chloroacetate salts with sodium cyanide followed by acidification.[1][2] Electrosynthesis by cathodic reduction of carbon dioxide and anodic oxidation of acetonitrile also affords cyanoacetic acid.[3]

Cyanoacetic acid is used to do cyanoacetylation, first convenient method described by J. Slätt.[4]

It is about 1000x more acidic than acetic acid, with a pKa of 2.5. Upon heating at 160 °C, it undergoes decarboxylation to give acetonitrile:

C3H3NO2 → C2H3N + CO2

Applications[edit]

The largest scale reaction is its esterification to give ethyl cyanoacrylate. As of 2007, more than 10,000 tons of cyanoacetic acid were produced annually.

Cyanoacetic acid is a versatile intermediate in the preparation of chemicals. it is a precursor to synthetic caffeine via the intermediacy of theophylline. It is a building block for many drugs, including dextromethorphan, amiloride, sulfadimethoxine, and allopurinol.[1]

Safety[edit]

The LD50 (oral, rats) is 1.5 g/kg.[1]

References[edit]

  1. ^ a b c d Harald Strittmatter, Stefan Hildbrand and Peter Pollak Malonic Acid and Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry 2007, Wiley-VCH, Weinheim. doi: 10.1002/14356007.a16_063.pub2
  2. ^ Inglis, J. K. H. (1928). "Ethyl Cyanoacetate". Organic Syntheses 8: 74. doi:10.15227/orgsyn.008.0074. 
  3. ^ Barba, Fructuoso; Batanero, Belen (2004). "Paired Electrosynthesis of Cyanoacetic Acid". The Journal of organic chemistry 69 (7): 2423-2426. doi:10.1021/jo0358473. 
  4. ^ Bergman, Jan; Romero, Ivan; Slätt, Johnny (2004). "Cyanoacetylation of indoles, pyrroles and aromatic amines with the combination cyanoacetic acid and acetic anhydride". Synthesis 16: 2760-2765. doi:10.1055/s-2004-831164.