Org. Synth. 1954, 34, 76
DOI: 10.15227/orgsyn.034.0076
PHENANTHRENEQUINONE
Submitted by Ray Wendland and John LaLonde
1.
Checked by William S. Johnson and Sol Shulman.
1. Procedure
In a 3-l. three-necked flask equipped with a reflux condenser, a sealed mechanical stirrer, and a 1-l. dropping funnel, are placed 100 g. (0.56 mole) of phenanthrene (Note 1), 210 g. (2.1 moles) of chromic acid (Note 2), and 1 l. of water. The stirrer is started, and 450 ml. of concentrated sulfuric acid is added from the dropping funnel into the suspension at such a rate that gentle boiling is induced (Note 3). After addition of the sulfuric acid is complete, a mixture of 210 g. (2.1 moles) of chromic acid and 500 ml. of water is added carefully to the reaction mixture from the dropping funnel (Note 4). The resulting mixture is boiled under reflux for 20 minutes.
After being cooled to room temperature the reaction mixture is poured into an equal volume of water and chilled to 10° in an ice bath. The crude precipitate is separated by suction filtration and thoroughly washed with cold water until the washings no longer show any chrome green color. The precipitate is triturated with three 300-ml. portions of boiling water and filtered to remove the diphenic acid formed in the reaction. The precipitate is then triturated with several (4–6) 300-ml. portions of hot 40% sodium bisulfite solution and again filtered (Note 5). The insoluble material is a mixture of anthraquinone and some resinous products derived from anthracene and other contaminants present in the starting material (Note 6). The sodium bisulfite filtrates are combined and cooled to 5° in an ice bath. The precipitate which separates is collected by suction filtration; then it is transferred to a 1-l. beaker and finely dispersed in 300 ml. of water. To this suspension is added, with good stirring, 500 ml. of a saturated solution of sodium carbonate. The deep orange phenanthrenequinone which is liberated is separated by suction filtration (Note 7), washed well with cold water, and dried on a porcelain plate. The yield of product, melting at 205–208° cor., is 52–56 g. (44–48%). Further purification may be accomplished by crystallization from 95% ethanol (100 ml./ g.). The recovery of first-crop material is over 80%, m.p. 208.5–210° cor.
2. Notes
1.
Reilly Tar and Chemical Company practical grade phenanthrene is crystallized from boiling
toluene using
Norit. One crystallization is sufficient to produce material melting at about
99.5°. The checkers employed
Eastman Kodak Company technical grade (90%) phenanthrene.
2.
Technical grade chromic acid (99.5% CrO3) in flake form was used.
3.
It is safe to add 100 ml. of acid all at once to start the oxidation, but as soon as the temperature rises to 70–75° the remainder must be added slowly in order to avoid violent boiling.
4.
One-half (250 ml.) of the mixture is added carefully (the reaction may become vigorous at this stage), and 20–25 minutes is allowed for the oxidation to proceed spontaneously. The remaining mixture is then added slowly.
5.
A heated
Büchner funnel is preferably used to prevent clogging by crystallization.
6.
The
anthraquinone may be purified by extracting the insoluble material with a
150-ml. solution of potassium hydroxide and
sodium hydrosulfite (approximately 10% by weight of each). The resulting red solution is quickly filtered by suction, and
hydrogen peroxide is added to the filtrate until a yellow precipitate appears. Dilute
hydrochloric acid is added until the mixture is acidic to litmus, and the precipitate is collected by suction filtration, washed well with water, and air-dried.
Five to seven grams of
anthraquinone, m.p.
280–283°, may thus be obtained.
7.
The filtrate should be treated with more
sodium carbonate to test for completeness of precipitation.
3. Discussion
Phenanthrenequinone has been prepared by treatment of
phenanthrene with
chromic acid in
acetic acid;
2 potassium dichromate in
sulfuric acid;
3,4,5 hydrogen peroxide in
acetic acid;
6,7 selenium dioxide above 250°;
8 iodic acid in
acetic acid,
9 and
chromyl chloride.
10 It also can be prepared from
benzil with
aluminum chloride at 120°
11 and from
biphenyl-2,2'-dialdehyde with
potassium cyanide.
12
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
Diphenic acid
biphenyl-2,2'-dialdehyde
ethanol (64-17-5)
sulfuric acid (7664-93-9)
hydrochloric acid (7647-01-0)
acetic acid (64-19-7)
sodium carbonate (497-19-8)
potassium cyanide (151-50-8)
sodium hydrosulfite (7775-14-6)
sodium bisulfite (7631-90-5)
Anthraquinone (84-65-1)
Norit (7782-42-5)
aluminum chloride (3495-54-3)
Benzil (134-81-6)
selenium dioxide (7446-08-4)
potassium hydroxide (1310-58-3)
toluene (108-88-3)
chromic acid (7738-94-5)
hydrogen peroxide (7722-84-1)
anthracene (120-12-7)
phenanthrenequinone (84-11-7)
iodic acid (7782-68-5)
potassium dichromate (7778-50-9)
chromyl chloride
phenanthrene (85-01-8)
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