Isatin

From Sciencemadness Wiki
Jump to: navigation, search
Isatin
Names
IUPAC name
1H-Indole-2,3-dione
Other names
2,3-Dioxo-2,3-dihydroindole
2,3-Diketoindoline
2,3-Dioxindole
2,3-Dioxoindoline
2,3-Indolinedione
Indole-2,3-dione
o-Aminobenzoylformic anhydride
Tribulin
Properties
C8H5NO2
Molar mass 147.1308 g/mol
Appearance Orange-red solid
Odor Aromatic, candy-like
Density 1.472 g/cm3[1]
Melting point 189–191 °C (372–376 °F; 462–464 K) [2]
Boiling point Decomposes
0.19 g/100 ml (20 °C)
Solubility Soluble in acetone, acetonitrile, DMF, DMSO, ethanol, ethyl acetate, methanol, propylene glycol
Poorly soluble in diethyl ether, THF, methyl tert-butyl ether, toluene, xylene
Vapor pressure ~0 mmHg
Thermochemistry
251.8 kJ/mol[3]
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
7740 mg/kg (rat, IP)
Related compounds
Related compounds
Indigo dye
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Isatin, also known as tribulin, is an organic compound with formula C8H5NO2.

Properties

Chemical

Reaction of isatin with phosphorus pentachloride, followed by reduction with white phosphorus or Zn powder, yields indigo dye.

Dimerization of isatin with potassium borohydride in methanol yields indirubin. This represent the indigo pigment's red component.[4]

The oxidation of isatin using hydrogen peroxide or chromium trioxide yields isatoic anhydride. If peroxydisulfuric acid is used instead, various 1,4‑benzoxazines are obtained.

Physical

Isatin is a reddish-orange solid, almost insoluble in water, but more soluble in some organic solvents. It has a distinct odor, reminiscent of some types of candies.

Availability

Isatin can be bought from chemical suppliers.

Isatin can be found in plants of the genus Isatis[5] (hence its name) as well as in Couroupita guianensis (cannonball tree)[6].

Preparation

Isatin can be prepared by oxidation of indigo dye using nitric acid. Chromic acid can also be used.

The Sandmeyer methodology is the oldest and straightforward way for the synthesis of isatin. This involves the condensation between chloral hydrate and a primary arylamine (e.g. aniline), in the presence of hydroxylamine hydrochloride, in aq. sol. of sodium sulfate to form an α‐isonitrosoacetanilide. Isolation of this intermediate and subsequent electrophilic cyclization promoted by strong acids (e.g. sulfuric acid) furnishes isatin in >75% yield.[7]

Projects

Handling

Safety

Isatin appears to have low toxicity. It is known to occur in some plant species.

Storage

In closed bottles

Disposal

No special disposal is required. Can be dumped in trash. Alternatively, it can be turned into indigo blue and disposed off.

References

  1. Palenik, Gus J.; Koziol, Anna E.; Katritzky, Alan R.; Fan, Wei-Qiang; Journal of the Chemical Society. Chemical communications; nb. 9; (1990); p. 715 - 716
  2. Shiri, Morteza; Salehi, Parvin; Mohammadpour, Zeinab; Salehi, Peyman; Notash, Behrouz; Synthesis; vol. 53; nb. 6; (2021); p. 1149 - 1156
  3. Matos, M. Agostinha R.; Miranda, Margarida S.; Morals, Victor M.F.; Liebman, Joel F.; Organic and Biomolecular Chemistry; vol. 1; nb. 14; (2003); p. 2566 - 2571
  4. Wang, Cuiling; Yan, Jiaxu; Du, Mo; Burlison, Joseph A.; Li, Chi; Sun, Yanni; Zhao, Danqing; Liu, Jianli (May 2017). "One step synthesis of indirubins by reductive coupling of isatins with KBH 4". Tetrahedron. 73 (19): 2780–2785
  5. Jue Zhou, July 2011, African Journal of Traditional, Complementary and Alternative Medicines 8(5 Suppl):33-45, "Analysis of the extracts of Isatis tinctoria by new analytical approaches of HPLC, MS AND NMR"
  6. Rahul R. Tripathi, September 2013, International Letters of Chemistry Physics and Astronomy 15:119-12, "An Extraction of the Isatin from the Couroupita guianesis (Cannon Ball Tree) and a Novel Synthesis of the N,N'-(2-oxo-3'H-spiro[indoline-3,2'-[1,3,4thiadiazole]-3',5'-diyl]diacetamidefrom the Isatin"]
  7. https://zenodo.org/records/1426793

Relevant Sciencemadness threads