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CRESOLS

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Originally appearing in Volume V07, Page 412 of the 1911 Encyclopedia Britannica.
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CRESOLS or METHYL PHENOLS, C7H80 or C6H4• See also:

CH3.0H. The three isomeric cresols are found in the See also:tar obtained in the destructive See also:distillation of See also:coal, See also:beech-See also:wood and See also:pine. The crude cresol obtained from tar cannot be separated into its different constituents by fractional distillation, since the boiling points of the three isomers are very See also:close together. The pure substances are best obtained by See also:fusion of the corresponding See also:toluene sulphonic acids with potash. Ortho-cresol, CH3(1)•CsH4.0H(2), occurs as sulphate in the urine of the See also:horse. It may be prepared by fusion of ortho-toluene sulphonic See also:acid with potash; by the See also:action of See also:phosphorus pent-See also:oxide on See also:carvacrol; or by the action of See also:zinc chloride on camphor. It is a crystalline solid, which melts at 30° C. and boils at 19o.8° C. Fusion with alkalis converts it into salicylic acid. See also:Meta-cresol,CH3(1) • See also:C6H4.0H(3), is formed when See also:thymol (paraisopropyl-meta-cresol) is heated with phosphorus pentoxide. Propylene is liberated during the reaction, and the phosphoric acid ester of meta-cresol which is formed is then fused with potash. It can also be prepared by distilling meta-oxyuvitic acid with See also:lime, or by the action of See also:air on boiling toluene in the presence of See also:aluminium chloride (C. See also:Friedel and J.

M. Crafts, See also:

Ann. Chien. Phys., 1888 [6], 14, p. 436). It solidifies in a freezing mixture, on the addition of a crystal of phenol, and then melts at 3°-4° C. It boils at 2o2°•8 C. Its aqueous See also:solution is coloured bluish-See also:violet by ferric chloride. See also:Para-cresol, CH3(f)•C6H4.0H(4), occurs as sulphate in the urine of the horse. It is also found in horse's See also:liver, being one of the putrefaction products of tyrosine. It may be prepared by the fusion of para-toluene sulphonic acid with potash; by the action of nitrous acid on para-toluidine; or by See also:heating para-oxyphenyl acetic acid with lime. It crystallizes in prisms which melt at 36° C, and See also:boil at 2010.8 C.

It is soluble in See also:

water, and the aqueous solution gives a See also:blue coloration with ferric chloride. When treated with hydrochloric acid and See also:potassium chlorate, no chlorinated See also:quinones are obtained (M. S. See also:Southworth, Ann. (1873), 168, p. 271), a behaviour which distinguishes it from ortho- and meta-cresol. On the See also:composition of commercial cresylic acid see A. H. See also:Allen, Jour. See also:Soc. Chem. See also:Industry (1890), 9, p.

141. See also See also:

CREOSOTE.

End of Article: CRESOLS

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