A Manual of the Chemistry of the Carbon Compounds

TU&' GHEMISTRY OF
PYROM0CIC ALDEHYDE OR FOBFUKOL C6H4O8
Is a light, oily liquid, boiling at 162°, and possessing a peculiar
aromatio odour. It is found amongst the products of destructive distillation
of sugar, and is also produced, together with methyl alcohol,
when fir-wood is heated with water for a considerable time under a
pressure of 100 lb. to the inch. Furfurol is best produced by distilling
bran with dilute sulphuric acid; iustead of bran, flour, sawdust,
or gum may also be used. These bodies contain an insoluble
substance, which, when boiled with very dilute sulphuric acid, is converted
into a brownish sweet syrup; and this, by distillation with
sulphuric acid, yields furfural. Furfurol combines with the acid
sulphites of the alkali-metals, forming crystalline compounds, and
reduces an aramoniacal silver-solution.
When furfurol is in contact with aqueous ammonia, it is converted
tuto Jwrjuramide C^HUOJNJ, a yellowish-white, crystalline, insoluble
substance, which by acids is again resolved into its constituents;
whilst, by dilute boiling potash, it is converted into an isomeride,
called furfarinc; it is but sparingly soluble in water, but freely in
alcohol; its solution has a strong alkaline reaction. With acids it
forms a series of beautifully erystalliaable salts, having an intensely
bitter taste.
Fu/rfmyl alcohol C6H0Ojj is produced, together with pyromucic
acid, by the action of caustic potash on furfurol:—
2C6H4O2 + KOH = C6H8K03 + C6H,j02
It is an oily liquid, which distils at 170°—180° with partial decomposition.
Tetraphenol C4H^0 is a limpid liquid, boiling u.t 32°, uiul having
a peculiar smell; it is produced by heating pyromucic acid with
alkalies:—
2C4HSO.COH + KOH = C4HSO.CQ.OK +
Fneusol Cfifi^ This isomeride of fhruirol has been obtained by
boiling seaweeds with dilute sulphimo acid; it is a liquid closely
resembling fnvfurol, both in its physical and chemical properties. It
boils at 171°, and yields, with silver oxide and water, j8 pyromneu
add CgH.Oj, crystallizing ia small rhoraboidal plates, melting at
130°,
PYKHOL C4H5N AND CARBOPYBROLAM1DE O5H0ONH8.
These two compounds are formed by the destructive distillation of
ammonium pyromucate. On evaporation the aqueous portion of the
distillate, carbopyrrolainide, is obtained in brilliant plates. By the
aotion of boiling baryta-water it is resolved into ammonia and carte'