A Manual of the Chemistry of the Carbon Compounds

196 THE CHEMISTRY OF
When aldehyde is heated with acetic anhydride to 180°, combination
takes place, and ethidcne diacetaie is produced:—
This compound is an oily liquid, boiling at 169°, and possessing an
alliaceous odour.
The compounds formed by the union of chloral, with water and
alcohols (page 146) have to be regarded as compounds of trichloretliidene
:—
Chloral Hydrate or
Triclilorothidone Alcohol. Chloral Alcoholate,
By treating chloral alcoholate with phosphorus pentachloride the
C HC1 1
hydtoxyl is replaced by chlorine, and tetrachlorethyl oxide 2 njr* \ 0
is formed (see page 112).
OLYOOLLYL COMPOUNDS.
GLYCOMIC ACID OB OXAOET1C ACID C2H4O8.
This acid can he produced by different reactions. It is formed by
oxidiging glycol with weak nitric acid;—
C
I
H CKLOH
CHyOH
CO.OH
and also by heating metallic chloracetatea or bromacetates with
water >-
CHaCl CHj.OH
| + H2O = | + KC1
CO.OK OO.OH
Glycollio acid is, however, more conveniently prepared by oxidizing
ethyl alcohol with nitric acid. One volume of nitric acid (V3&
specific gravity) is mixed with two volumes of alcohol (90 per cent.);
after standing for some time evolution of gas commences. The liquid
is now kept at a temperature of 20° until this evolution ceases, and
then evaporated on a water-batli to the consistency of a syrup. Tlie
residue is dissolved in water, and the boiling solution neutralized with
chalk. On cooling, impure calcium glycollate crystallizes out, which
is boiled with milk of lime in order to remove by-products (glyoxnl