Copper aspirinate

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Copper aspirinate

IUPAC name	dicopper 2-acetyloxybenzoate
Other names	copper(II) aspirinate, cupric aspirinate, cupric aspirin complex
Identifiers
CAS number
PubChem	92244
SMILES	CC(=O)OC1=CC=CC=C1C(=O)[O-].CC(=O)OC1= CC=CC=C1C(=O)[O-].CC(=O)OC1=CC=CC=C1C(=O) [O-].CC(=O)OC1=CC=CC=C1C(=O)[O-].[Cu+2].[Cu+2]
InChI	InChI=1/4C9H8O4.2Cu/c41-6(10)13-8-5-3 -2-4-7(8)9(11)12;;/h42-5H,1H3,(H,11,12); ;/q;;;;2+2/p-4/f4C9H7O4.2Cu/q4-1;2m
Properties
Molecular formula	C₃₆H₂₈Cu₂O₁₆
Molar mass	843.69g/mol
Appearance	Bright blue crystalline solid.
Related Compounds
Other cations	Zinc aspirinate, Aluminum aspirinate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Copper(II) aspirinate is an aspirin chelate of copper(II) cations (Cu²⁺). It is used to treat rheumatoid arthritis.

1 Preparation
2 Medicinal Use
3 See Also
4 Footnotes

[edit] Preparation

Copper aspirinate can be prepared by several methods. In one route of preparation, an excess of acetylsalicylic acid is dissolved with sodium carbonate or sodium bicarbonate, making the aspirin soluble in aqueous solution. Sodium hydroxide is not suitable for this purpose, because it will hydrolyse acetylsalicylic acid into salicylic acid and sodium acetate.

HC₉H₇O₄ + NaHCO₃ → NaC₉H₇O₄ + CO₂↑ + H₂O

The resulting solution is then filtered to remove any undissolved acetylsalicylic acid and is mixed with a solution containing Cu²⁺ cations (copper(II) sulfate is suitable), precipitating bright blue crystals of copper aspirinate immediately. The crystals can then be filtered from solution, washed, and recrystallized. An excess of ASA is used in the first step, because it eliminates the possibility of unreacted carbonate anions from precipitating the copper in this step.