A Publication
of Reliable Methods
for the Preparation
of Organic Compounds
Annual Volume
Org. Synth. 1925, 5, 79
DOI: 10.15227/orgsyn.005.0079
Submitted by Louis F. Fieser
Checked by C. R. Noller and W. R. White.
1. Procedure
A mixture of 70 g. (0.36 mole) of pure 1,4-aminonaphthol hydrochloride and 2100 cc. of water at 30° in a 5-l. flask is stirred for a few minutes in order to dissolve most of the material and then treated with 100 cc. of concentrated sulfuric acid. The mixture is heated to the boiling point until all the precipitated amine sulfate has been brought into solution. The solution is somewhat pink. The hot solution is poured rapidly through a large funnel (without a paper), which has been warmed on the steam bath, into a 5-l. round-bottomed flask containing a filtered solution at room temperature of 70 g. (2.4 moles) of potassium dichromate in 1 l. of water. The flask is shaken to mix the contents thoroughly. The quinone separates at once as a mass of fine, yellow needles. After cooling to 25° the material is collected, washed with water, and dried at 30–40°. The crude product is dull yellow; it melts at 124–125° to a dark liquid and weighs 53–55 g. (Note 1).
The crude naphthoquinone is warmed gently on the steam bath with 1.5 l. of ether, when it rapidly dissolves and leaves in suspension a slight amount of dark, fluffy material. The solution is shaken for ten minutes with 10 g. of decolorizing carbon; it is then filtered, and the ether is distilled from a steam bath until crystals begin to form. The solution is then allowed to cool undisturbed, and the clear canary-yellow prisms which separate are collected and washed with ether. The mother liquor is clarified by shaking as before with 7 g. of decolorizing carbon, filtered, and evaporated to a small volume until crystals begin to separate. The crystals are again washed with ether, and the mother liquor is clarified and evaporated once more. The final crop of material is dull in color but yields a pure product on recrystallization. All the material is of a high quality and melts at 124–125° to a clear yellow liquid; the yield is 44–46 g. (78–81 per cent of the theoretical amount) (Note 2).
2. Notes
1. The method of oxidation is essentially that of Russig.1 The product obtained is slightly but definitely better than that produced at a lower temperature, or by adding the sulfuric acid to the dichromate solution, or by using ferric chloride. These latter procedures give the same yield, but the product is less pure and contains a black, ether-soluble impurity which must be washed out carefully after crystallization from ether.
2. This procedure2 avoids the tedious purification by distillation with superheated steam in vacuum, which was described in the original method in Org. Syn. Coll. Vol. I, 375 (1932).
3. Discussion
1,4-Naphthoquinone can be prepared by the oxidation of naphthalene,3 1,4-aminonaphthol,4, 5 1,4-naphthylene diamine,4 and 1,4-naphthylamine sulfonic acid.6 Oxidation of 1,4-aminonaphthol is the most convenient method.7
This preparation is referenced from:

References and Notes
  1. Russig, J. prakt. Chem. (2) 62, 31 (1900).
  2. Fieser and Fieser, J. Am. Chem. Soc. 57, 491 (1935).
  3. Groves, Ann. 167, 357 (1873); Plimpton, J. Chem. Soc. 37, 634 (1880); Japp and Miller, ibid. 39, 220 (1881); Miller, J. Russ. Phys. Chem. Soc. 16, 414 (1884); Arnold and Larson, J. Org. Chem. 5, 250 (1940).
  4. Liebermann, Ann. 183, 242 (1876).
  5. Zincke and Wiegand, Ann. 286, 70 (1895); Russig, J. prakt. Chem. (2) 62, 31 (1900); Conant and Fieser, J. Am. Chem. Soc. 46, 1862 (1924); Liebermann, Ber. 14, 1796 (1881).
  6. Monnet, Reverdin, and Nölting, Ber. 12, 2306 (1879).
  7. Conant and Fieser, J. Am. Chem. Soc. 46, 1862 (1924).

Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

1,4-Aminonaphthol hydrochloride


sulfuric acid (7664-93-9)

ether (60-29-7)

decolorizing carbon (7782-42-5)

Naphthalene (91-20-3)

ferric chloride (7705-08-0)

potassium dichromate (7778-50-9)

naphthoquinone (130-15-4)

1,4-naphthylene diamine (2243-61-0)

1,4-naphthylamine sulfonic acid (84-86-6)