moderately soluble in water and gives a fine violet coloration with alkalies.

185°.

Pseudo-cumene gives a crystalline trinitro derivative, melting at The corresponding trinitro-mesitylene melts at 232°. 1025. Other trialkyl benzenes are ethyl-dimethyl benzene :

C6H3(CH3)2C2H6,

1:3:4, boiling at 183°-184°.

Its isomer with the positions 1:3:5 boils at 180°-182°, and is obtained by the distillation of ethyl-methyl ketone with sulphuric acid.

(CH3)2

Isoamyl-dimethyl-benzene, CH, CH, CH,.CH(CH3),'

at 232°-233°, and methyl-dipropyl-benzene :

C6H3.(CH3)(C3H7),α = (1:3:5),

boils at 243°-248°. It gives uvitic acid on oxidation.

, 1:3:4, boils

Tetra-alkyl-benzenes include durene or tetramethyl-benzene, C6H2(CH3)4 (1:3:4:6). It is obtained by the action of sodium on monobrom-pseudo-cumene and ethylic iodide, and forms prisms melting at 80° and boiling between 189° and 191°.

A dinitro product, C(NO2)2(CH3), melting at 205°, and a dibrom-durene, C6Br2(CH3)4, melting at 199°, are known. On oxidation durene yields cumidic, C6H2(CH3)2(CO.OH)2, and cumylic:

acids.

C6H2(CH3)3CO.OH,

An isomeric tetramethyl benzene, (1:2:3:5), from brom-mesitylene and methylic iodide, boils at 192° and does not solidify at -18°.

By the action of haloid alkyl compounds on benzene under the influence of aluminic chloride it appears possible to obtain benzenes in which all the hydrogen has been replaced by alcohol radicals.

In this way mono-, di-, &c., to hexa-ethyl benzene have been obtained and isolated.

The hexa-ethyl benzene, C6(C2H5)6, prepared in this manner, is said to resist all oxidising agents.

RR

Haloid benzyl compounds are obtainable from the alcohol by the action of haloid acids or phosphorus haloids. The chloride and bromide are also obtained by the direct action of the Cl and Br on toluene at its boiling point. They are isomeric with the halogen toluenes (§ 1012). Their vapours are very irritating to the eyes, &c.

Benzyl chloride, CH5.CH,Cl, is a colourless liquid boiling at 176°. The bromide boils between 2010 and 202°. The iodide, which is obtained by the reaction of C6H5.CH,Cl and HI in the cold, is a crystalline body, melting at 24°, and which cannot be distilled undecomposed.

Benzylic Ethers.-Sodium alkylates react with C6H5.CH2Cl to form benzyl ethers, which are decomposed by chlorine gas into alkyl chloride, benzoic aldehyde, and hydrochloric acid :

C6H5.CH2.O.CnH2n+1 + Cl2 = C2H2n+1Cl + C6H5.CHO + HCl.

Benzyl-methyl ether, C6H5.CH2.0.CH3, is liquid and boils at 1670-168°; benzyl-ethyl ether boils at 185°. Potassic phenylate also yields benzyl-phenyl ether with CH5.CH,Cl, as colourless crystals, melting at 38°-39° and boiling at 286°-287°. Dibenzyl ether, C6H5.CH2.O.CH2.C6H5, is obtained directly from benzyl alcohol by heating with boric anhydride:

2C6H5.CH2.OH + B2O3 = 2HBO2 + (C6H5.CH2)2O,

or by heating the chloride with water to 190°. It is a colourless oil boiling above 300°.

Benzyl salts are obtained by mixing the organic acid and sulphuric acid with benzyl alcohol, or by the reaction between C6H5.CH2Cl and the salts of the particular acids. Benzyl acetate, CH5.CH2.O.C2H3O, boils at 210° and possesses an odour somewhat resembling hyacinths. The propionate, C2H2O.O.CH2.C6H5, the butyrate,

CH,O2.CH2.C6H5,

and the isobutyrate, (CH3),CH.CO2.CH2.C6H5, boiling at 229°, are known.

Sulphur compounds of benzyl result from the action of benzyl chloride on the alkaline sulphides. Benzyl mercaptan, CH5.CH.SH, is a powerfully refracting liquid, smelling like leeks and boiling at 1940-195°. Dibenzyl sulphide, (C6H5CH2)2S, crystallises in needles, melting at 49°.

Benzylamines result as halogen salts from the reaction between benzyl haloids and ammonia.

Benzylamine, C6H5.CH.NH2, is a colourless liquid, miscible with water, boiling at 183°, and is isomeric with the toluidines. Dibenzylamine, (CH,CH2),NH, is an oily liquid, boiling at about 300°. Tribenzylamine, (CHCH2)3N, is a solid body crystallising in colourless plates, which melt at 91°, and is decomposed by distillation.

From benzylamine ureas, mustard oils, guanidines, and other compounds have been prepared and described; benzyl phosphines have also been obtained.

1028. Substitution Products from Benzyl Compounds. By the action of chlorine on boiling parachlor-toluene or on a solution of iodine in cold benzyl chloride, parachlor-benzyl chloride, CH4Cl.CH2Cl, isomeric

with the dichlor-toluenes, has been obtained as a liquid boiling at 214°. By heating with argentic acetate it yields parachlor-benzyl acetate, boiling point 240°, which gives by saponification parachlor-benzyl alcohol, CHCI.CH2.OH, a body crystallising in long needles, melting at 66°, and distilling unchanged.

By the continued action of chlorine, assisted by heating, in the presence of iodine on chlor-benzyl chloride, higher substitution products are obtained, which are nearly all liquid and can be distilled. Pentachlor-benzyl chloride, CC,.CH2Cl, is a solid melting at 103° and boiling at 325°. Benzyl acetate dissolves in cold fuming nitric acid, forming nitro-benzyl acetate, which is further converted by ammonia at 100° into acetamide and nitro-benzyl alcohol :

C&H (NO2).CH2.OH,

the latter substance crystallising in needles melting at 93° and very soluble in water.

Metanitro-benzyl alcohol is produced along with nitro-benzyl aldehyde by treating metanitro-benzoic acid with alcoholic potash. Orthohydroxy-benzyl alcohol, or saligenin, CH1(OH).CH2.ÕH, is obtained from its glucoside, salicin, along with grape sugar by the fermentive action of emulsin and saliva. It crystallises in pearly tables, easily soluble in alcohol, ether, and hot water, melts at 82°, and sublimes at 100°. Ferric chloride produces a deep blue colour in its solutions. Under the influence of diluted acids it is partly resinified and converted into its anhydride, the amorphous saliretin:

2C2H ̧O2 = OH2 + C14H1403.

Salicin, C13H1807 = C6H2O(OH),O.CH,CH2OH, occurs in the bark and leaves of most varieties of willows and several poplars. For the preparation of salicin, willow bark, reduced to small pieces, is boiled with water, the solution freed from tannin and other substances by treatment with plumbic acetate, and the lead removed by SH, and filtration. On evaporation the salicin crystallises from the solution in colourless prisms of bitter taste, easily soluble in water and melting at 198°. With acetic anhydride a tetra-aceto-salicin, C13H,(CH3O),O,, is produced, crystallising in needles.

Anisyl alcohol, para-oxymethyl-benzyl alcohol:

CH10O2 = C6H4 CH2.OH
.O.CH3

may also be classified with these oxy substitution products. It is obtained, together with potassic anisate, by the action of alcoholic potassic hydrate on anisic aldehyde. It crystallises in brilliant prisms, melts at 25°, and boils at 258°-259°.

Alcohols of the Formula CH100.

1029. Tolyl alcohol, or paramethyl-benzyl alcohol:

CH,(CH3).CH2.OH,

is produced by the action of alcoholic potash on paratoluylic aldehyde. It crystallises in needles, melts at 59°, and boils at 217°. Hydrochloric acid converts it into liquid tolyl chloride, CH ̧(CH3).CÌ¿Cl.

Tolyl chloride is obtained by the action of chlorine on boiling xylene. That from coal-tar xylene mixture (§ 1021) boils between 190° and 200°.

Styronyl alcohol, or primary phenethyl alcohol, CH5.CH2.CH2.OH, is obtained from its bromide or chloride in like manner to benzyl alcohol from the benzyl haloids; it is a liquid of 225° boiling point.

This styronyl chloride, C6H5.CH2.CH2Cl, is also produced by the action of chlorine on boiling ethyl benzene as a liquid decomposed on distillation (§ 1018).

Secondary phenethyl alcohol, CH,.CH(OH).CH ̧, is obtained by the action of sodium amalgam on aceto-phenone. Methyl-phenyl ketone, CH.CO.CH3, is a pleasant-smelling oil boiling at 2020-203°.

Higher Homologues.

1030. Only a few of these bodies are known.

C,H120, primary phenyl-propyl alcohol, C6H5.CH2.CH2.CH2.OH, obtained by the saponification of liquid storax and by addition of hydrogen to cinnamic alcohol, is a thickish oil boiling at 235°. Ethyl-phenyl ketone, when treated with nascent hydrogen, yields B-secondary phenylpropyl alcohol, C6H5.CH(OH).CH2.CH3, which boils at 210°-211°.

C10H140, cumin alcohol, parapropyl or parisopropyl-benzyl alcohol, CH2(C3H7)CH2OH, is obtained by treating cuminic aldehyde with alcoholic potash as.a colourless oil boiling at 243°.

Carvol, C10H140, obtained from oil of caraway (Carum Carvi), and also contained in turmeric root, boils at 225°-230°, and has sp. gr. 95.

C18H300, Sycoceryl Alcohol. This alcohol occurs as acetate in the resin of Ficus rubiginosa, from which it may be obtained by saponification in needles melting at 90°.