A Manual of the Chemistry of the Carbon Compounds

482 THE VHBMISTRY OF
Piperonaldehyde C8H,,Oa crystallizes from water in transparent,
brilliant prisms, melting at 263°, and smelling like cumarin; it
combines like other aldehydes with the acid sulphites of the alkalimetals.
Piperonyl Alcohol C8H8O8 is produced by the action of sodiumamalgam
and water on the aldehyde, and forms colourless crystals,
melting at 51°.
Piperonie Acid C$H6O4 is produced by the further action of
potassium permanganate on tlie aldehyde. It crystallizes in long
needles, melting at 228°. When it is heated with dilute hydrochloric
acid to 170°, it i3 resolved into finely divided carbon, and protocatechuic
acid. Phosphorus pentachloride converts it into diclUoropiperonyl
chloride C,HSC14O2.COC1, which yields with water diohloropiperonie
acid; and the latter, when boiled with water, is resolved into carbon
dioxide, hydrochloric acid, and protocatechuic acid.
On the other hand, by heating protocatechuic acid with potash, and
methene di-iodide (di-iodomethane), it is converted into piperonic
add. These reactions prove that the piperonyl compounds are constituted
as follows:—
Pipeionyl y Alcohol. PiperonaldeViyde.
{ 0> CH 8 { "
CH2.OH (COH
Pipuronlc Acid. Dlohloropiperoaio Acid.
C6HJ O/ CF » CJL | o) CC1 «
HCO.OH ' "(CO.OH
SIHAKSB
This base exists as sulphocyanate in the seed of white mustard.
To obtain this salt the crushed seed, which has been freed from the
fatty oil by pressing, is exhausted with alcohol; it is alight crystalline
powder, consisting of needles. The free suiapine is not known;
on boiling one of its salts with water, the base is resolved into oholtm
and bibasic sinapic acid G,,!!,^^ crystallizing from hot water in
colourless prisms. This decomposition is explained by the following
equation:—
Sinapic Acid.
.CO)
HO.CO
Cboline.