Organic Syntheses, Coll. Vol. 5, p.632 (1973); Vol. 48, p.94 (1968).
Caution! Many pyrene
derivatives are carcinogens. Contact of the skin with these materials should be avoided.
In a 100-ml. pressure vessel (Note 1)
are placed 14.0 g. (0.050 mole) of 3-bromopyrene (Note 2)
, 0.5 g. of copper bronze powder (Note 3)
, 1.5 g. of cuprous oxide (Note 4)
, and 60 ml. of 10% aqueous sodium hydroxide (Note 5)
. The vessel is sealed, heated rapidly with shaking to 275–280°, and maintained at this temperature for 3 hours. The vessel is allowed to cool and is opened, and the contents are poured into a 500-ml. beaker
containing 200 ml. of water (Note 6)
. The mixture is filtered, and the filter cake is washed with water until the washings become neutral to pH paper. The combined filtrate and washings, which show a blue fluorescence, are made acid to Congo red paper with 20% aqueous sulfuric acid
. The precipitate is collected by filtration, washed free of acid with water, and dried in an oven
at 100° to give ca.
9 g. of a gray solid.
The solid is boiled under reflux with ca. 175 ml. of benzene
for 1 hour, and the benzene-insoluble material is removed from the hot mixture by filtration through a medium-grade sintered-glass funnel (Note 7)
. Small portions of activated alumina are added to the hot filtrate until a strong green fluorescence develops; 20–25 g.
is needed (Note 8)
. The mixture is boiled (Note 9)
under reflux for 15 minutes and filtered hot. On concentration and cooling, the fluorescent, lemon-yellow filtrate yields 3-hydroxypyrene
as light yellow needles, m.p. 179–181°
. An additional quantity of equally pure product is obtained by further concentration of the mother liquor. The total yield is 5.5–6.0 g.
) (Note 10)
Stainless steel and Hastelloy-C vessels were used with equivalent results.
This material, m.p. 93–95°
, is readily prepared in high yields (78–86%
) from commercial pyrene
by the method of the submitter,2
who used pyrene, m.p. 151–153°, obtained from Chemicals Division, Union Carbide Corp.
Copper bronze, type 3310, obtained from U.S. Bronze Powder Works, Inc., Flemington, New Jersey
, was used. The use of some grades of copper powder
leads to a considerably lower yield.
Technical grade cuprous oxide obtained from Baker and Adamson Products, General Chemical Division, Allied Chemical Corp.
, was used.
The amount of sodium hydroxide
used does not affect the yield, provided that it is present in a quantity well in excess of that required by the stoichiometry.
The funnel should be preheated to prevent crystallization of the product in its pores. The filtration process can be accelerated by scraping the muddy cake from the funnel surface.
The use of a larger quantity reduces the yield with no significant improvement in quality.
The presence of the alumina
causes the mixture to bump violently. Agitation of the boiling mixture with a magnetically driven stirring bar
helps to alleviate this problem. The vessel should be securely clamped.
The submitter obtained 25–29 g.
) of product when the reaction was run with 56.2 g. (0.20 mole) of the bromide
in a 400-ml. pressure vessel
4. Merits of the Preparation
It has been shown6
that two mechanisms, elimination-addition (benzyne
) and SN
2 displacement, are operative in the liquid-phase hydrolysis of halogenated aromatic compounds. The formation of isomeric phenols as a result of the availability of the benzyne
route makes the reaction of limited synthetic value. The incorporation of the copper-cuprous oxide
system suppresses reaction via the benzyne
route, so that the present method has general utility for the preparation of isomer-free phenols. For example, p-cresol
is the only cresol
formed from p-bromotoluene
under the conditions of this preparation.
The methods previously reported for the preparation of 3-hydroxypyrene
have been found to be unsatisfactory, because of both very poor yields and difficulties in operation.
This preparation is referenced from:
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