Salicylaldehyde

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Salicylaldehyde
IUPAC name 2-Hydroxybenzaldehyde
Other names Salicylaldehyde
Salicylic aldehyde
Identifiers
CAS number [90-02-8]
SMILES OC1=C(C=O)C=CC=C1
Properties
Molecular formula C7H6O2
Molar mass 122.12 g/mol
Density 1.146 g/cm3
Melting point

-7 °C

Boiling point

196-197 °C

Related compounds
Related compounds Salicylic acid
Benzaldehyde
Salicylaldoxime
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Salicylaldehyde, or 2-hydroxybenzaldehyde, is the chemical compound with the formula C6H4CHO-2-OH[1]. This colourless oily liquid has a bitter almond odor at higher concentration and a characteristic buckwheat aroma at lower concentration. Salycylaldehyde was identified as a characteristic aroma component of buckwheat [2] . Salicylaldehyde is a key precursor to a variety chelating agents, some of which are commercially important. It can be prepared from phenol and chloroform by heating with sodium hydroxide in a Reimer-Tiemann reaction.

Salicylaldehyde is a common highly-functionalized arene that has often been exploited as a precursor to still other chemicals, which are shown in the figure, from the left: catechol, benzofuran, a salicylaldehydimine (R = alkyl or aryl), 3-carbethoxycoumarin.

Figure. Illustrative compounds derived from salicylaldehyde.

[edit] Other hydroxybenzaldehydes

Three isomers exist of hydroxybenzaldehyde with the hydroxyl group in the ortho, meta, or para position.

ortho-hydroxybenzaldehyde meta-hydroxybenzaldehyde para-hydroxybenzaldehyde
Synonyms salisylaldehyde 3-hydroxybenzaldehyde 4-hydroxybenzaldehyde
CAS number [90-02-8] [100-83-4] [123-08-0]
Appearance colorless oily liquid light-tan crystals yellow to tan powder
Density 1.146 g/cm3 1.226 ± 0.06 g/cm3
Melting point -7 °C 100-103 °C 112-116 °C
Boiling point 196-197 °C 191 °C 50 mm Hg 310.00 - 311.00 °C
hydroxybenzaldehydes[6][7].

3-Hydroxybenzaldehyde has been prepared from m-nitrobenzaldehyde in a sequence of nitro group [[organic reduction, diazotisation of the amine and its hydrolysis[8][9]

[edit] References

  1. ^ Merck Index, 11th Edition, 8295.
  2. ^ Janes D, Kreft S: Salicylaldehyde is a characteristic aroma component of buckwheat groats, Food Chemistry 2008; 109: 293-298, doi:10.1016/j.foodchem.2007.12.032
  3. ^ Dakin, H. D. (1941). "Catechol". Org. Synth.; Coll. Vol. 1: 149. 
  4. ^ Horning, E. C.; Horning, M. G.; Dimmig, D. A. (1955). "3-Carbethoxycoumarin". Org. Synth.; Coll. Vol. 3: 165. 
  5. ^ Burgstahler, A. W.; Worden, L. R. (1973). "Coumarone". Org. Synth.; Coll. Vol. 5: 251. 
  6. ^ Sigma-Aldrich.com
  7. ^ 4-hydroxybenzaldehyde - 123-08-0
  8. ^ Organic Syntheses, Coll. Vol. 3, p.453 (1955); Vol. 25, p.55 (1945). http://www.orgsynth.com/orgsyn/orgsyn/prepContent.asp?prep=cv3p0453
  9. ^ Organic Syntheses, Coll. Vol. 3, p.564 (1955); Vol. 29, p.63 (1949). http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv3p0564