When phenol is passed through a red-hot tube a complex decomposition takes place, resulting in the formation of benzene, toluene, naphthalene, &c. (J.
Paraffins are found in all crude oils, and olefines in varying proportions in the majority, while acetylene has been found in Baku oil; members of the benzene group and its derivatives, notably benzene and toluene, occur in all petroleums. Naphthenes are the chief components of some oils, as already indicated, and occur in varying quantities in many others.
Compounds derived by substituting aliphatic radicals in the benzene nucleus; such a compound is methylbenzene or toluene, C 6 H 5 CH 3.
This compound is readily oxidized to benzoic acid, C 6 H 5 000H, the aromatic residue being unattacked; nitric and sulphuric acids produce nitro-toluenes, C6H4 CH3 N02j and toluene sulphonic acids, C 6 H 4 CH 3 SO 3 H; chlorination may result in the formation of derivatives substituted either in the aromatic nucleus or in the side chain; the former substitution occurs most readily, chlor-toluenes, C 6 H 4 CH 3 Cl, being formed, while the latter, which needs an elevation in temperature or other auxiliary, yields benzyl chloride, C 6 H 5 CH 2 C1, and benzal chloride, C 6 11 5 CHC1 2.
Toluene or mono-methylbenzene results from the pyrocondensation of a mixture of acetylene and allylene.
He assumed that if we have one atom 1 It is now established that ortho compounds do exist in isomeric forms, instances being provided by chlor-, brom-, and amino-toluene, chlorphenol, and chloraniline; but arguments, e.g.
A similar contradiction apparently exists with regard to the specific volume, for while benzene has a specific volume correspinding to Claus' formula, toluene, or methylbenzene, rather points to Kekule's.
It is formed when the vapours of toluene, stilbene, dibenzyl, ortho-ditolyl, or coumarone and benzene are passed through a red-hot tube; by distilling morphine with zinc dust; and, with anthracene, by the action of sodium on ortho-brombenzyl bromide (C. L.
It is excreted when many aromatic compounds, such as benzoic acid and toluene, are taken internally.
The light oil fraction of the coal-tar distillate, which comes over below 140° and consists principally of benzene, toluene and the xylenes, yields on fractionation (i) various volatile impurities such as carbon disulphide, (2) the benzene fraction boiling at about 80° C., (3) the toluene fraction boiling at too°, (4) the xylene fraction boiling at 140°.
The toluene fraction requires a more thorough washing with sulphuric acid in order to eliminate the thiotolene, which is sulphonated much less readily than thiophene.
The pure substances are best obtained by fusion of the corresponding toluene sulphonic acids with potash.
It may be prepared by fusion of ortho-toluene sulphonic acid with potash; by the action of phosphorus pentoxide on carvacrol; or by the action of zinc chloride on camphor.
It can also be prepared by distilling meta-oxyuvitic acid with lime, or by the action of air on boiling toluene in the presence of aluminium chloride (C. Friedel and J.
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 heating para-oxyphenyl acetic acid with lime.
An important oxidation synthesis of aromatic acids is from hydrocarbons with aliphatic side chains; thus toluene, or methylbenzene, yields benzoic acid, the xylenes, or dimethyl-benzene, yield methyl-benzoic acids and phthalic acids.
Technically it is prepared from toluene, by converting it into benzyl chloride, which is then heated with lead nitrate: C 6 H 5 CH 2 C1 +Pb (N03)2 = 2NO 2 +PbC1.
Reduction by means of hydriodic acid and phosphorus at 140° C. gives toluene, whilst on distillation with alcoholic potash, toluene and benzoic acid are formed.
It occurs naturally in some resins, especially in gum benzoin (from Styrax benzoin), in dragon's blood, and as a benzyl ester in Peru and Tolu balsams. It can be prepared by the oxidation of toluene, benzyl alcohol, benzaldehyde and cinnamic acid; by the oxidation of benzene with manganese dioxide and concentrated sulphuric acid in the cold (L.
It is made commercially by boiling benzotrichloride (obtained from toluene) with milk of lime, the calcium benzoate so obtained being then decomposed by hydrochloric acid 2C 6 H 5 CC1 3 +4Ca(OH) 2 = (C6H6000)2Ca-1-3CaC12+4H20.
Para-xylene is obtained when camphor is distilled with zinc chloride, but it is best prepared from para-brom-toluene or dibrombenzene, methyl iodide and sodium.
TOLUENE, Or Methylbenzene, C7H8 Or C6H5 CH 3, an aromatic hydrocarbon; the first homologue of benzene.
Hofmann and Muspratt, and they adopted the name toluol (anglicized to toluene), which was proposed by Berzelius.
It may be obtained synthetically by Fittig and Tollens's method (above); by Friedel and Craft's process, devised in 1877, of acting with aluminium chloride on a mixture of benzene and methyl chloride; this reaction leads to the production of higher homologues which may, however, break down under the continued action of the aluminium chloride; or by heating the toluene carboxylic acids obtained by oxidizing the higher homologues of benzene.
It may be synthesized from toluene; more interesting is its production when acetone dicarboxylic ester is condensed with the aid of sodium.