C14H802 See also:

• C14H802 ANTHRAQUINONE

ANTHRAQUINONE  , an important derivative of See also:

• ANTHRACENE (from the Greek avOpa, coal)

anthracene, first prepared in x834 by A . See also:

• LAURENT, FRANCOIS (1810–1887)

Laurent . It is prepared commercially from anthracene by stirring a sludge of anthracene and See also:

• WATER

water in See also:

• HORIZONTAL

horizontal cylinders with a mixture of See also:

• SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium bichromate and See also:

• CAUSTIC (Gr. rcavvraubs, burning)

caustic soda . This suspension is then run through a conical See also:

• MILL
• MILL (O. Eng. mylen, later myln, or miln, adapted from the late Lat. molina, cf. Fr. moulin, from Lat. mola, a mill, molere, to grind; from the same root, mol, is derived " meal;" the word appears in other Teutonic languages, cf. Du. molen, Ger. muhle)
• MILL, JAMES (1773-1836)
• MILL, JOHN (c. 1645–1707)
• MILL, JOHN STUART (1806-1873)

mill in See also:

• ORDER
• ORDER (through Fr. ordre, for earlier ordene, from Lat. ordo, ordinis, rank, service, arrangement; the ultimate source is generally taken to be the root seen in Lat. oriri, rise, arise, begin; cf. " origin ")
• ORDER, HOLY

order to remove all grit, the cones of the mill fitting so tightly that water cannot pass through unless the mill is See also:

• RUNNING

running; the See also:

• SPEED, JOHN (1552–1629)

speed of the mill when working is about 3000 revolutions per See also:

• MINUTE
• MINUTE (Lat. minutes, small; minuere, to make less)

minute . After this treatment, the mixture is run into See also:

• LEAD
• LEAD (pronounced iced)

lead-lined vats and treated with sulphuric See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid, See also:

• STEAM
• STEAM (0. Eng. steam, vapour, smoke, cf. Du. steam; the origin is unknown)

steam is blown through the mixture in order to bring it to the See also:

• BOIL

boil, and the anthracene is rapidly oxidized to See also:

• ANTHRAQUINONE, C14H802

anthraquinone . When the oxidation is See also:

• COMPLETE

complete. the anthraquinone is separated in a filterpress, washed and heated to r 20° C. with commercial oil of See also:

• VITRIOL

vitriol, using about 22 parts of vitriol to r of anthraquinone . It is then removed to lead-lined tanks and again washed with water and dried; the product obtained contains about 95 % of anthraquinone . It may be purified by sublimation . Various synthetic processes have been used for the preparation of anthraquinone . A . See also:

• BEHR, WILLIAM JOSEPH (1775–1851)

Behr and W . A. v .

Dorp (Ber.,1874,7,p.578) obtained orthobenzoyl benzoic acid by See also:

• HEATING

heating See also:

• PHTHALIC

phthalic anhydride with See also:

• BENZENE, C6H6

benzene in the presence of See also:

• ALUMINIUM (symbol Al; atomic weight 27.0)

aluminium chloride . This See also:

• COMPOUND
• COMPOUND (from Lat. componere, to combine or put together)

compound on heating with phosphoric anhydride loses water and yields anthraquinone, See also:

• C6H4
• C6H4(CH213r)2

C6H4<CO>O ,CiH4`000Hj5~C6H4.<CO/ CsH4 . It may be prepared in a similar manner by heating phthalyl chloride with benzene in the presence of aluminium chloride . Dioxy- and tetraoxy-anthraquinones are obtained when See also:

• META

meta-oxyand dimeta-dioxy-benzoic acids are heated with concentrated sulphuric acid . Anthraquinone crystallizes in yellow needles or prisms, which melt at 277° C . It is soluble in hot benzene, sublimes easily, and is very See also:

• STABLE

stable towards oxidizing agents . On the other See also:

• HAND
• HAND (a word common to Teutonic languages; cf. Ger. Hand, Goth. handus)
• HAND, FERDINAND GOTTHELF (1786-185r)

hand, it is readily attacked by reducing agents . With See also:

• ZINC

zinc dust in presence of caustic soda it yields the secondary See also:

• ALCOHOL

alcohol oxanthranol, C6H4: CO•CHOH : C6H4, with See also:

• TIN (Lat.- stannum, whence the chemical symbol " Sn "; atomic weight =117.6, 0=16)

tin and hydrochloric acid, the phenolic compound anthranol, C6H4: CO•C(OH): CsH4; and with hydriodic acid at r 5o C. or on See also:

• DISTILLATION (from the Lat. distillare, more correctly destillare, to drop or trickle down)

distillation with zinc dust, the See also:

• HYDROCARBON

hydrocarbon anthracene, C44H10 . When fused with caustic potash, it gives benzoic acid . It behaves more as a ketone than as a quinone, since with See also:

• HYDROXYLAMINE, NH2OH

hydroxylamine it yields an oxime, and on reduction with zinc dust and caustic soda it yields a secondary alcohol, whilst it cannot be reduced by means of sulphurous acid . Various sulphonic acids of anthraquinone are known, as well as oxy-derivatives, for the preparation and properties of which see See also:

• ALIZARIN, or I

ALIZARIN .