ANTHRACENE (from the

See also:

• GREEK
• GREEK, ETRUSCAN AND

Greek avOpa,

See also:

• COAL

coal)  , Cr4H1o, a hydrocarbon obtained from the fraction of the coal-tar distillate boiling between 270° and 400° C . This high boiling fraction is allowed to stand for some days, when it partially solidifies . It is then separated in a centrifugal machine, the low melting-point impurities are removed by means of hot water, and the residue is finally hot-pressed . The crude anthracene cake is purified by treatment with the higher pyridine bases, the operation being carried out in large steam-jacketed boilers . The whole mass dissolves on heating, and the anthracene crystallizes out on cooling . The crystallized anthracene is then removed by a centrifugal separator and the process of solution in the pyridine bases is repeated . Finally the anthracene is purified by sublimation . Many synthetical processes for the preparation of anthracene and its derivatives are known . It is formed by the condensation of acetylene tetrabromide with benzene in the presence of aluminium chloride: Br•CH•Br C6H6+ I +C6H6=4HBr+C6H4K . I 4H4, Br•CH•Br and similarly from methylene dibromide and benzene, and also when benzyl chloride is heated with aluminium chloride to 200° C . By condensing ortho-brombenzyl bromide with sodium, C . L .

Jackson and J . F . White (Ber., 1879, 12, p .