Org. Synth. 1963, 43, 15
DOI: 10.15227/orgsyn.043.0015
9-CHLOROANTHRACENE
[Anthracene, 9-chloro-]
Submitted by D. C. Nonhebel
1
Checked by R. B. Greenwald and E. J. Corey.
1. Procedure
In a dry, 1-l., two-necked flask, equipped with a mechanical stirrer and a reflux condenser fitted with a drying tube, are placed 17.8 g. (0.100 mole) of anthracene (Note 1), 27.2 g. (0.202 mole) of anhydrous cupric chloride (Note 2), and 500 ml. of carbon tetrachloride (Note 3). The reaction mixture is stirred and heated under reflux for 18–24 hours. The brown cupric chloride is gradually converted to white cuprous chloride, and hydrogen chloride is gradually evolved. At the end of the reaction the cuprous chloride is removed by filtration, and the carbon tetrachloride solution is passed through a 35-mm. Chromatographic column filled with 200 g. of alumina (Note 4). The column is eluted with 400 ml. of carbon tetrachloride. The combined eluates are evaporated to dryness to give 19–21 g. (89–99%) of 9-chloroanthracene as a lemon-yellow solid, m.p. 102–104° (Note 5). Crystallization of the product from petroleum ether (b.p. 60–80°) gives 16–17 g. (75–80%) of 9-chloroanthracene as yellow needles, m.p. 104–106°.
2. Notes
1.
Anthracene, B. D. H. (blue fluorescence), was used. Traces of
ethylene glycol,
glycerol,
ethanol, or water considerably retard the reaction and lead to unsatisfactory results.
2.
Anhydrous
cupric chloride is dried in an
oven at 110–120° for several hours and stored in a
desiccator or over
phosphorus pentoxide before use.
3.
Chlorobenzene or
sym-tetrachlorethane may be used instead of
carbon tetrachloride as solvent, in which case the reaction is complete as soon as the mixture has reached reflux. The product is liable to be contaminated by a small amount of
9,10-dichloroanthracene.
4.
Merck alumina or Spence Type H alumina was used.
5.
The
9-chloroanthracene at this stage usually contains a small amount of unreacted
anthracene.
3. Discussion
9-Chloroanthracene has been prepared by the action of
chlorine,
2 t-butyl hypochlorite,
3 1,3-dichloro-5,5-dimethylhydantoin,
4 or
phosphorus pentachloride5 on
anthracene. The present method is a one-step synthesis giving a high yield of
9-chloroanthracene from readily available starting materials.
The method outlined can be applied to the preparation in better than 90% yield of the 10-chloro derivatives of 9-alkyl-,
6 9-aryl-,
6 and 9-halogenoanthracenes.
7 For the less reactive substrates
chlorobenzene should be used as solvent. This is the only satisfactory procedure for the preparation of
9-bromo-10-chloroanthracene.
7 Other methods of chlorination lead to mixtures of the desired compound and
9,10-dichloroanthracene.
Pyrene can likewise be converted to
1-chloropyrene (
90% yield).
8 Analogous procedures with
cupric bromide lead to the brominated compounds in similar high yields.
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
petroleum ether
sym-tetrachlorethane
ethanol (64-17-5)
hydrogen chloride (7647-01-0)
phosphorus pentachloride (10026-13-8)
glycerol (56-81-5)
carbon tetrachloride (56-23-5)
chlorobenzene (108-90-7)
chlorine (7782-50-5)
ethylene glycol (107-21-1)
cuprous chloride (7758-89-6)
cupric chloride (7447-39-4)
anthracene (120-12-7)
cupric bromide (7789-45-9)
pyrene (129-00-0)
9-Chloroanthracene,
Anthracene, 9-chloro- (716-53-0)
9,10-dichloroanthracene (605-48-1)
1,3-dichloro-5,5-dimethylhydantoin (118-52-5)
9-bromo-10-chloroanthracene
1-chloropyrene (34244-14-9)
phosphorus pentoxide (1314-56-3)
t-BUTYL HYPOCHLORITE (507-40-4)
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