Organic Reactions Volume 4 - Sciencemadness Dot Org

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ORGANIC REACTIONS
Reaction of Maleic Anhydride with Aromatic Compounds. 1. Wholly
Aromatic Systems. The central ring of the anthracene nucleus contains a
characteristic diene system, for the hydrocarbon forms stable adducts
with maleic anhydride, maleic acid, dimethyl maleate, fumaric acid,
dimethyl fumarate, citraconic anhydride, mesaconic acid, crotonic acid,
and dibromomaleic anhydride. 128,236 9,10-Dihydroanthracene-9,10-endoa,/?-succinic
anhydride (LXI) shows unmistakably the absorption spectrum
of a simple benzene derivative. 237
The reaction of maleic anhydride with polycyclic hydrocarbons containing
the anthracene nucleus has been shown to be reversible. 123 Identical
mixtures of hydrocarbon, maleic anhydride, and adduct were
obtained by heating xylene solutions of either the pure adduct or the
components in equimolecular proportion. In Table II are indicated the
TABLE II
EQUILIBKIUM MIXTUKES FEOM POLYCYCLIC HYDKOCARBONS AND MALEIC ANHYDRIDE
IN BOILING XYLENE
Adduct in
Equilibrium
Hydrocarbon Mixture (%)
Anthracene
9-Methylanthracene
9,10-Dimethylanthracene
1,2-Benzanthracene
9-Phenylanthracene
1,2,5,6-Dibenzanthracene
3-Methylcholanthrene
9,10-Diphenylanthracene
equilibrium mixtures which were obtained in this manner. Preparation
of the maleic anhydride adduct, followed by pyrolytic reversal of the
reaction, has been suggested as a means of purifying anthracene 238 ~ 240
and cholanthrene. 241
236 DIeIs, Alder, and Beckmann, Ann., 486, 191 (1931).
237 Clar, Ber., 65, 503 (1932).
238 Polyakova, Org. Chem. Ind. U.S.S.R., 7, 305 (1940) [C. A., 35, 4008 (1941)].
239 Dermer and King, J. Am. Chem. Soc, 63, 3232 (1941).
240 Winans, U. S. pat. 2,347,228 [C. A., 39, 92 (1945)].
241 Bachmann, /. Org. Chem., 3, 434 (1938),
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