A Manual of the Chemistry of the Carbon Compounds

THE OARBON COMPOUNDS. 371
1*4 Para-oxyknzoic Add,—This third isoraeric acid is obtained by
the action of nitrous acid upon an aqueous solution of paramidobenzoic
acid, as well as by the action of fusing caustic potash upon
anisic acid, paracreaol and many resins (gum benzoin, aloes, dragon'sblood,
&c).
It is much more soluble in water than salicylic acid, and crystallizes
in monoclinio prisms, with one molecule of water. It melts at 210°,
decomposing at the .same time partly into carbon dioxide and phenoL
Its aqueous solution gives with ferric chloride a yellow precipitate.
Phosphorus pentachloride converts it into parachlorobenzoyl chloride.
Anisyl Aldehyde, or Methyl-pwa-oscybeimiMehydB C6H4| QQJJ 8 -—
The volatile oils of Pimpinclla Anisa, Anetfoum Faimulvm, Artemisia
Dtacwmtlus, and other UmbelliferiB, and the oil of Jllidum anisaium,
contain as principal constitutent anethl C6H4 ] n JJ ** which, by the
action of dilute nitric acid or chromic acid, is oxidized to anisyl
aldehyde, an oily liquid, boiling at 248°, and possessing an aromatic
odour. It forms with the acid sulphites of the alkali-metals crystalline
compounds, and combines with nascent hydrogen with the
formation of Anisyl alcohol or methyl-parcMicybenzj/l akohol
( OCH
CjH^ i QH 6H' wn * c k crystallizes in shining prisms, melting at 28°,
and boiling at about 250°. It has a faint odour and burning taste;
on heating it with hydrochloric acid it is converted into the liquid
anisyl chloride C6H4 1 ° 5 &
AnisicAcid,otMeihyl-para-oxybe'imieAeidC^L^ QRQ'JI, is formed
by the prolonged action of oxidizing agents upon the above-mentioned
oils, ana on paracresol-methyl-ether, and has also been produced by
heating para-oxybenzoio acid with caustic potash and methyl iodide.
It crystallizes in colourless needles, melting at 175°, and subliming
without undergoing decomposition. By heating it with hydrochloric
acid or hydriodic acid, or by fusing it with caustic potash, it yields
para-oxybenzolc acid, and by distillation with caustic baryta it is
resolved into carbon dioxide and anisol.
Nitrani&ie Aeid O^NOj) j j^oJcftl is obtained by acting on oil of
anise-seed with not nitric acid of specific gravity of 1°*4, and forms small
glistening needles, melting at 180*,
Einitranisio Aeid C^CNO^ {^Q^JJ is formed together with
di« and trinitranisol, when nitranisic acid is boiled with fuming
nitric acid. It crystallizes from hot water in large yellowish, sinning
needles, melting at 173°. In alcoholic potash it dissolves with a fine
red colour, and boiling alkalis decompose it with the formation of
dinitropara-oxybenzoic acid.
2