Cyanoacetic acid

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

Cyanoacetic acid
Names
Preferred IUPAC name
2-Cyanoacetic acid
Identifiers
3D model (JSmol)
506325
ChEBI
ChemSpider
ECHA InfoCard 100.006.131
EC Number
  • 206-743-9
UNII
UN number 1759
  • InChI=1S/C3H3NO2/c4-2-1-3(5)6/h1H2,(H,5,6)
    Key: MLIREBYILWEBDM-UHFFFAOYSA-N
  • InChI=1/C3H3NO2/c4-2-1-3(5)6/h1H2,(H,5,6)
    Key: MLIREBYILWEBDM-UHFFFAOYAD
  • C(C#N)C(=O)O
Properties
C3H3NO2
Molar mass 85.06 g/mol
Appearance colorless solid
Density 1.287 g/cm3
Melting point 69-70 °C
Boiling point 108 °C (15 mm Hg)
1000 g/L (20 °C) in water
Hazards
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation mark
Danger
H302, H314, H332
P260, P261, P264, P270, P271, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P330, P363, P405, P501
Flash point 107 °C (225 °F; 380 K)
Related compounds
Related
Ethyl cyanoacetate
Cyanoacetamide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Preparation and reactions

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

The largest scale reaction is its esterification to give the corresponding ester ethyl cyanoacetate, which is then transformed to ethyl cyanoacrylate used as superglue, via reaction with formaldehyde. 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] and also for Peldesine.

Safety

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

References
  1. 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. PMID 15049640.
  4. Bergman, Jan; Romero, Ivan; Slätt, Johnny (2004). "Cyanoacetylation of indoles, pyrroles and aromatic amines with the combination cyanoacetic acid and acetic anhydride". Synthesis. 2004 (16): 2760–2765. doi:10.1055/s-2004-831164. hdl:10616/37961.
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