Naphthalene-2-sulfonic acid

Naphthalene-2-sulfonic acid
Names
Preferred IUPAC name
Naphthalene-2-sulfonic acid
Other names
2-Naphthalenesulfonic acid, napsylate (salt), napsilate (salt)
Identifiers
CAS Number
  • 120-18-3
3D model (JSmol)
  • Interactive image
Beilstein Reference
 1955756
ChEMBL
  • ChEMBL1234624
ChemSpider
  • 8113
ECHA InfoCard 100.003.978 Edit this at Wikidata
EC Number
  • 204-375-3
PubChem CID
  • 8420
UNII
  • O9S4K2S25E
CompTox Dashboard (EPA)
  • DTXSID5044788 Edit this at Wikidata
InChI
  • InChI=1S/C10H8O3S/c11-14(12,13)10-6-5-8-3-1-2-4-9(8)7-10/h1-7H,(H,11,12,13)
    Key: KVBGVZZKJNLNJU-UHFFFAOYSA-N
  • C1=CC=C2C=C(C=CC2=C1)S(=O)(=O)O
Properties
Chemical formula
 C10H8O3S
Molar mass 208.23 g·mol−1 (anhydrous)
Appearance White solid
Melting point 124 °C (255 °F; 397 K) (monohydrate)
Solubility in water
 good
Hazards
GHS labelling:
Pictograms
 GHS05: CorrosiveGHS07: Exclamation mark
Danger
Hazard statements
 H302, H314
Precautionary statements
 P260, P264, P270, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P330, P363, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
Chemical compound

Naphthalene-2-sulfonic acid is an organic compound with the formula C10H7SO3H. A colorless, water-soluble solid, it is often available as the mono- and trihydrates C10H7SO3H.2H2O. It is one of two monosulfonic acids of naphthalene, the other being naphthalene-1-sulfonic acid. The compound is mainly used in the production of dyes via nitration en route to aminonaphthalenesulfonic acids. The compound is prepared by sulfonation of naphthalene with sulfuric acid, however under equilibrating conditions that allow the 1-sulfonic acid isomer to convert to the more stable 2-sulfonic acid.[1]

Naphthalene-2-sulfonic acid undergoes many reactions, some of which are or were of commercial interest. Fusion with sodium hydroxide followed by acidification gives 2-naphthol. It is an intermediate in the formation of 2,6-, 2,7- and 1,6-naphthalene disulfonic acids as well as 1,3,6-naphthalenetrisulfonic acid. Naphthalene-2-sulfonic acid condenses with formaldehyde to give polymeric sulfonic acids.[1]

References

  1. ^ a b Gerald Booth (2005). "Naphthalene Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a17_009. ISBN 3-527-30673-0.