Improvements in the Manufacture or Preparation of Alkylised Uric Acids.
Year: 1899

page_text: Date of Application, 27th Sept., 1899-Accepted, 28th Oct., 1899
COMPLETE SPECIFICATION.
Improvements in the Manufacture or Preparation of Alkylised Uric
Acids.
I, GEORGE WILLIAM JOHNSON, of 47, Lincoln's Inn Fields, in the County of
London, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad by C. F. Boehringer & Soehne, of Waldhof,
near Mannheim, in the German Empire) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
In the Specification of the Application for Letters Patent No. 1678 dated the
24th January 1899 is described the manufacture or preparation of alkylised uric
acids by the reduction of oxymethylene derivatives of uric acid (obtained in
accordance with the British Patent No. 204478) in accordance with the following
formula:
R =
N.CH₂(OH) + H₂
=
RNCH, H₂O.
My foreign correspondents have since discovered that it is not necessary to
start with completely formed mono-formaldehyde compounds of uric acid, or
their akyl derivatives for the preparation of the (7)-methyl-uric acid or its
alkyl derivatives, but that the uric acid or an alkyl derivative thereof can be
used as the initial material and be submitted to the action of a reducing agent
in the presence of formaldhyde, so that the formation of the oxymethylene com-
pounds and their reduction take place in one and the same operation.
The following examples will serve to illustrate the nature of this invention and
the manner in which it can be performed.
EXAMPLE 1.
Preparation of (7)-methyl-uric acid from uric acid.
40 parts by volume of concentrated hydrochloric acid are mixed with six parts
by volume of a 40 per cent, formaldehyde solution and saturated with gaseous
hydrochloric acid at 0° Centigrade.
To this solution are added 5 parts by weight of uric acid and 15 parts by weight
of granulated tin the reduction being then allowed to take its course at 0° Centi-
grade for about 24 hours, the mixture being meanwhile constantly stirred
and the reduction being completed by heating the mixture for about 12 hours
to from 80° to 90° Centigrade.
The liquid is then, and whilst still hot diluted with warm water in quantity
equal to it in volume, or not exceeding 1 times its volume and it is then
filtered to free it from any unused tin or undissolved uric acid which it may
contain and allowed to cool. At this stage the (7)-methyl-uric acid will crystal-
lize out in an almost perfect state of purity in minute brilliant needles." The
remainder can be obtained from the filtrate after the hydrochloric acid has been
got rid of by evaporation, and the syrupy residue has been treated by means of
water.
(2.) Preparation of (3.7)-dimethyl-uric acid from (3)-methyl-uric acid.
À mixture of 100 parts by volume of concentrated hydrochloric acid (specific
gravity 119) and 5 parts by volume of formaldehyde solution is poured over
077

page_text: 10 parts by weight of (3)-methyl-uric acid and then added 40 parts by weight
of granulated tin. The whole is first thoroughly mixed together for from six
to seven hours at room temperature, and then for the purpose of completing
the reduction, it is further heated for about three hours to from 70° to 80° Centi-
grade whilst being continuously stirred.
The mixture is then diluted with about double its volume of water and allowed
to cool. The (3.7)-dimethyl-uric acid is separated from the tin by boiling with
diluted ammonia and from this solution after it has been treated with charcoal,
the pure product is extracted by acidulating the solution with sulphuric acid.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
-
The manufacture or preparation of alkylized uric acids by reducing uric acid
or an akyl derivative thereof in the presence of formaldehyde as hereinbefore
explained.
JOHNSONS & WILLCOX.
47, Lincoln's Inn Fields, London, W.C., Agents.