Improvements in the Production of Azosafranine-derivates.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Production of Azosafranine-derivates.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby declare
the nature of this invention, (which has been communicated to me from abroad
by Leopold Cassella & Co., of Frankfort-on-Main, in the Empire of Germany,)
to be as follows:-
Combinations from diazosafranines and amines have already been described in
the Moniteur Scientifique on page 984 of the year 1886. Amongst other bases,
dimethylaniline is employed, and it is stated that a claret dye is obtained by
combining diazosafranines with solutions of the salts of the dialkylated anilines.
We have made the surprising discovery that colouring matters of quite a
different composition result, if the reaction is carried on, as in the British Patent
No. 348895, in the presence of organic acids, such as carbonic or acetic acids, or if
the operation is conducted in such a manner that the diazo chlorides come into
contact with the free bases. Then intense greenish blue to dark green dyestuffs
result. Presumably the dialkylamido group is thereby brought into connection
with the chromogene tie of the molecule.
EXAMPLE.
7.4 parts of tolusafranine are diazotised with 7 parts muriatic acid of 20 degrees
Bé and 1 part nitrite at 0 degree C. Then 20 parts of sodium acetate are added,
and immediately afterwards the solution of 3 parts diethylaniline in 300 litres
water and 2.3 parts muriatic acid is allowed to run in whilst stirring; the reaction
is then allowed to take place during 24 hours, the solution is heated to 90 degrees C.,
and the dyestuff precipitated with a little common salt.
In this example the safranine may be replaced by its homologues, by mono-
alkylsafranine or the unsymmetrically substituted dialkylsafranines; in place of
diethylaniline, dimethylaniline and the like can be used.
The dyestuffs thus obtained are easily soluble in water, they dye cotton, mor-
danted with tannin, fast to washing and milling, and possess very good fastness
to light. They are precipitated from their solutions by alkalis. They resist high
temperatures, as for instance in steaming printed goods, and surpass in this respect
all the azosafranine-derivates known hitherto.
Dated this 19th day of March 1807
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby declare
the nature of this invention, (which has been communicated to me from abroad

page_text: by Leopold Cassella & Co., of Frankfort-on-Main, 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;
Combinations from diazosafranines and amines have already been described
in the Moniteur Scientifique on page 984 of the year 1886. Amongst other bases,
dimethylaniline is employed, and it is stated that a claret dye is obtained by com-
bining diazosafranines with solutions of the salts of the dialkylated anilines.
We have made the surprising discovery that colouring matters of quite a different
composition result, if the reaction is carried on, as in the British Patent No. 348895,
in the presence of organic acids, such as acetic acids, or if the operation is conducted
in such a manner that the diazo chlorides comes into contact with the free bases.
Then intense greenish blue to dark green dyestuffs result. Presumably the dialkyl-
amido group is thereby brought into connection with the chromogene tie of the
molecule.
14
EXAMPLE.
7.4 parts of tolusafranine are diazotised with 7 parts muriatic acid of 20 degrees
Bé. and 1 part nitrite at 0 degree C. Then 20 parts of sodium acetate are added,
and immediately afterwards the solution of 3 parts diethylaniline in 300 litres
water and 2.3 parts muriatic acid is allowed to run in whilst stirring; the reaction
is then allowed to take place during 24 hours, the solution is heated to 90 degrees C.,
and the dyestuff precipitated with a little common salt.
In this example the safranine may be replaced by its homologues, by mono-
alkylsafranine or the unsymmetrically substituted dialkylsafranines; in place of
diethylaniline, dimethylaniline and the like can be used.
The dyestuffs thus obtained are easily soluble in water, they dye cotton, mor-
danted with tannin, fast fo washing and milling, and possess very good fastness to
light. They are precipitated from their solutions by alkalis. They resist high
temperatures, as for instance in steaming printed goods, and surpass in this respect
all the azosafranine-derivatives known hithertō.
The following is another example:-
37.3 parts by weight of dimethyl-safranine are diazotised by means of 36 parts
by weight of muriatic acid. of 21° Bé. and 7 parts by weight of nitrite. The excess
of the mineral acid is then neutralized by the addition of 11 parts by weight of
sodium carbonate at 0 degrees C. and immediately afterwards 15 parts by weight
of diethylaniline are introduced. The reaction is completed within about 24 hours.
The dyestuff is then filtered off and dried.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. Producing novel basic dyestuffs by combining diazo-safranines with alkylated
aromatic amines in the manner above described.
2. The coloring matters herein before, described.
Dated this 8th dow of December 1807⑈