Improvements in the Preparation of Alkylated Uric Acids.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Preparation of Alkylated Uric Acids.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Firm of C. F. Boehringer & Soehne, of
Waldhoff, near Mannheim, in the Empire of Germany), to be as follows:-
In the Specification of my application for Letters Patent No. 10005 (dated 11th
May 1896) I describe a method of preparing alkyl derivatives of uric acid up to the
tetralkyl derivatives by the action of halogen alkyls on an alkaline solution of uric
acid or of its alkyl derivatives.
I have now found that the alkylation of uric acid may be carried out not only by.
means of halogen alkyls, (the alcohol ethers, of halogen hydrides) but also
through the agency of ethers of other acids.
The ethers which are found to be most applicable to the alkylation process are
the alcohol ethers of those acids which previous investigation has shewn to possess
a high electrical conductivity (see Ostwald, Text-book of General Chemistry,
2nd Vol., 1,650), for example, nitric acid, ethylsulphuric acid, isethionic acid
benzenesulphonic acid, and sulphuric acid.
For the sake of illustration I give examples of the preparation of methyluric
acid by the action of methylic nitrate, methylic benzenesulphonate, and potas-
sium methylsulphate on an alkaline solution of uric acid according to this
invention the parts being by weight.
EXAMPLE I.
To 30 parts of uric acid are added 2100 parts of water and solution is effected
by the addition of 200 parts of 10 per cent. caustic potash; the liquid is then
heated in an autoclave with 24 parts of methylic nitrate and continuously agitated
during 3 hours at 80° centigrade. The hot clear liquid is treated with 50 parts of
concentrated hydrochloric acid and allowed to cool, and after remaining for several-
hours, the methyluric acid which has crystallised out is collected on the filter.
29 parts of methyluric acid are obtained in this manner, but the product is
contaminated with a small percentage of uric acid.
EXAMPLE II.
50 parts of uric acid are dissolved in 270 parts of 10 per cent. caustic potash
and 1250 parts of water and the solution is heated in an autoclave with 77 parts of
methylic benzenesulphonate and continuously agitated during 3 hours at 100°
centigrade. As the mass becomes gelatinous on cooling it is most advantageously
treated with hydrochloric acid whilst still hot until it has a strongly acid
reaction, when it is allowed to cool.
46 parts of methyluric acid are obtained in this manner, the product containing
some percentage of uric acid.

page_text: EXAMPLE III.
As
10 parts of uric acid are suspended in 60 parts of hot water and dissolved with
66 parts of double normal potash, and heated under pressure and agitated with
13 parts of potassium methylsulphate during 6 hours at 110° centigrade.
the liquid cools, unaltered uric acid separates out as acid potassium urate, which
can be removed by filtration. By adding hydrochloric acid to the hot filtrate
methyluric acid is precipitated and thus obtained in a state of purity.
Improvements in the Preparation of Alkylated Uric Acids.
I, JAMES YATE JOHNSON, of 47, Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by the Firm of C. F. Boehringer & Soehne, of
Waldhoff, near Mannheim, in the Empire of Germany,) 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 Letters Patent No. 10005 (dated 11th May 1896) is
described a method of preparing alkyl derivatives of uric acid up to the tetralkyl
derivatives by the action of halogen alkyls on an alkaline solution of uric acid or
of its alkyl derivatives.
I have now found that the alkylation of uric acid may be carried out not only by
means of halogen alkyls, (the alcohol ethers of halogen hydrides) but also
through the agency of ethers of other acids.
The ethers which are found to be most applicable to the alkylation process are
the alcohol ethers of those acids which previous investigation has shewn to possess
a high electrical conductivity (see Ostwald, Text-book of General Chemistry,
2nd vol., 1,650), for example, nitric acid, ethylsulphuric acid, isethionic acid,
benzenesulphonic acid, and sulphuric acid.
For the sake of illustration I give examples of the preparation of methyluric
acid by the action of methylic nitrate, methylic benzene-sulphonate, and potas-
sium methylsulphate on an alkaline solution of uric acid according to this
invention, the parts being by weight.
EXAMPLE I.
To 30 parts of uric acid are added 2100 parts of water, and solution is effected
by the addition of 200 parts of 10 per cent. caustic potash; the liquid is then
heated in an autoclave with 24 parts of methylic nitrate and continuously agitated
during 3 hours at 80° centigrade. The hot, clear liquid is treated with 50 parts of
concentrated hydrochloric acid and allowed to cool, and after remaining for several
hours, the methyluric acid which has crystallized out is collected on the filter.
29 parts of methyluric acid are obtained in this manner, but the product is
contaminated with a small percentage of uric acid.
EXAMPLE II.
50 parts of uric acid are dissolved in 270 parts of 10 per cent. caustic potash
and 1250 parts of water, the solution is heated in an autoclave with 77 parts of
methylic benzene-sulphonate and continuously agitated during 3 hours at 100°
centigrade. As the mass becomes gelatinous on cooling it is most advantageously

page_text: treated with hydrochloric acid whilst still hot until it has a strongly acid
reaction, when it is allowed to cool.
46 parts of methyluric acid are obtained in. this manner, the product containing
some percentage of uric acid.
EXAMPLE III.
10 parts of uric acid are suspended in 60 parts of hot water and dissolved with
66 parts of double normal potash, and heated under pressure, and agitated with
13 parts of potassium methyl-sulphate during 6 hours at 110° centigrade. As
the liquid cools, unaltered uric acid separates out as acid potassium urate, which
can be removed by filtration. By adding hydrochloric acid to the hot filtrate
methyluric acid is precipitated and thus obtained in a state of purity.
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 preparation of alkylated uric acids by causing the esters of acids which
possess a great electrical conductivity to act upon the alkaline salts of uric acid
or of the alkyl derivatives of uric acid as hereinbefore explained.
Dated this 20th day of December 1897
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.