A Manual of the Chemistry of the Carbon Compounds

248 THE CEEMISTBY OF
CH.gNH)
EydaiUcnn or Qlycolyl-wrea I > CO.—When urea is acted
CO.NH j
upon by inonobromacetyl bromide, monobroniacetyl area is formed,
a compound resembling tribromacetyl-urea. On heating this body
with alcoholic ammonia it is converted into hydantotn s—
The same body is formed, together with carbon dioxide, water, and
free iodine, when alloxou is heated with hydriodic acid. It forms
colourless crystals, possessing a faint sweet taste, and melting at 206°.
By boiling with baryta-water it takes up water, and is converted into
i NH CH CO H
hydantoic add or glycoluric add CO •! -sr^ * a .
AllanUSin C4H6N,O8 is contained in the allantoio liquid or urine of
the fcetal calf, and also in the urine of sucking calves. It is also produced,
together with oxalio acid and urea, by heating uric acid with
lead dioxide and water, It forms brilliant, transparent prisms, which
are sparingly soluble in water,
JBy the action of sodium amalgam and water it is converted into
glycolurih C4H8N4O4, which, when heated with acids, takes up water,
and is resolved into urea and glycolyl-urea. The constitution of these
compounds may therefore be expressed as follows $—
Allantoln. Olycolurile,
NH—C=N-CO.NHli NH-C=N—CO.NH.
I
CO
•
NH—CH.OH
XANTHINE, SAHCIXE, AND GUANINK.
Xauthine C.H.N/)4
Sardne C5H4N4O
Guanine C6HBN6O
These three compounds occur in the animal organism, Xanthino and
sarcine have also been obtained by reducing uric acid with sodium
amalgam and water, and xanthine is produced by the action of nitrous
acid upon guanine.
Xanthine is present in minute quantity in urine, and in nearly
all parts of the animal organism ; in larger quantity it has been found
as a constituent of certain urinary calculi. After tho continued use
of sulphur-baths urine contains larger quantities of xanthine. It is