Year: 1889

page_text: Date of Application, 22nd July, 1889
Complete Specification Left, 22nd Apr., 1890-Accepted, 31st May, 1890

page_text: reaction is completed, an acid is carefully added to the solution, whereby the free
amido compound is precipitated:
For the glucose may be substituted other reducing agents, that, like the glucose,
have a reducing action in presence of alkalies.
The amido compound is soluble with difficulty in the ordinary solvents. From
radical vinegar it separates in form of small crystals of brownish color. In alkalies it
dissolves with blue color when the alkaline solution is somewhat concentrated; on
further diluting this solution with cold water the blue color turns more and more to a
red blue, and finally there will result a red solution.
With acids the amido compound forms salts which are nearly insoluble in cold
water and when washed with cold water for a considerable time split up into the acid
and the base.
32
C. H. (OH) COC, H₂ (OH)2, can be produced two nitro compounds which
may be designated hereinafter as the alpha- and the beta-compound. The formation
of the one or the other of these compounds depends on the conditions under which
the experiment is made.
The alpha compound will be obtained when nitric acid is caused to act upon flavo-
purpurine in presence of concentrated sulphuric acid; and the beta compound is
formed when flavopurpurine is nitrated in presence of acetic acid or glacial acetic
acid hereinafter termed "radical vinegar," or other indifferent solvents.
This beta compound is a very valuable coloring matter and preferable to the beta-
nitralizarine by reason of its dyeing a tint considerably more yellow.
1. PRODUCTION OF BETA NITROFLAVOPURPURINE.
1 part of flavopurpurine in fine powder is mixed with 4 to 5 parts of radical
vinegar, heated to 300-35° C., and to the mass are slowly added 45 hundredth parts
of nitric acid of 60 per cent.
For the radical vinegar may be substituted indifferent compounds, such as hydro-
carbons, nitro-hydrocarbons or similar compounds.
After having added the nitric acid, the mass, which will have somewhat thickened,
is heated to 40°-45° C. for about an hour, the nitroflavopurpurine which has formed
is taken off by filtration, washed, and if hydrocarbons or similar compounds have been
used as solvents, it is treated with steam.
The nitroflavopurpurine is soluble with difficulty in the ordinary solvents. Hot
radical vinegar dissolves about 1 per cent. of it and from this solution the nitroflavo-
purpurine crystallises on cooling in the form of fine, ochre-yellow clustered needles.
It melts at 265° C. and decomposes at higher temperatures.
With metallic oxides it forms acid as well as neutral salts, most of which are soluble
with difficulty in water. It dyes alumina-mordanted fabrics an orange tint consider-
ably more yellow than that obtained with nitralizarine.
By treatment with reducing agents the betanitroflavopurpurine is converted into an
amido.compound.

page_text: 2. PRODUCTION OF THE AMIDO COMPOUND.
The following is an example of the process.
1 part of nitroflavopurpurine is dissolved in 50 parts of water and 3 parts of soda
lye of 35 per cent., there are then added 10 parts of glucose and the whole is heated
to 70°-80° C. until the color of the solution, which is red at first, has disappeared,
and a drop of it added to an excess of soda lye produces a pure blue tint. After
the reaction is completed, an acid is carefully added to the solution, whereby the free
amido compound is precipitated.
For the glucose may be substituted other reducing agents, that, like the glucose,
have a reducing action in presence of alkalies.
The amido compound is soluble with difficulty in the ordinary solvents. From
radical vinegar it separates in form of small crystals of brownish color. In alkalies
it dissolves with blue color when the alkaline solution is somewhat concentrated; on
further diluting this solution with cold water the blue color turns more and more to
a red-blue, and finally there will result a red solution.
With acids the amido compound forms salts which are nearly insoluble in cold
water and, when washed with cold water for a considerable time, split up into the acid
and the base.
Having now particularly described and ascertained the nature of this inven-
tiou and in what manner the same is to be performed I declare that what I
claim is :-
:―
1. The production of betanitroflavopurpurine of the melting point of 265° (). by the
action of nitric acid upon flavopurpurine in presence of acetic acid or other indifferent
solvent, substantially as described.
2. The conversion of the betanitroflavopurpurine referred to in the preceding claim
into an amido compound by submitting the betanitropurpurine in alkaline solution to
the action of glucose, sulphide of ammonium, protoxide of tin or any other of the
known reducing agents, substantially as described.
Dated this 16th day of April 1890.
ABEL & IMRAY,
Agents for the Applicant.