IMPRove- MENTS IN THE PRODUCTION OF PARANITRO COMPOUNDS
Year: 1881

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPRove-
MENTS IN THE PRODUCTION OF PARANITRO COMPOUNDS." A communication
from abroad by Messrs. Bindschedler and Busch, of Basle, in the Republic of
Switzerland
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 6th May 1881.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane,
in the County of Middlesex. "IMPROVEMENTS IN THE PRODUCTION OF PARANITRO
COMPOUNDS." [A communication from abroad by Messrs. Bindschedler and Busch,
of Basle, in the Republic of Switzerland.]
This Invention consists in the production of paranitro compounds from the
leukobases generated by the condensation of benzaldehyd with the primary,
secondary, and tertiary aromatic monamines, as also from the colouring matters
produced by oxidation of the condensation products of benzaldehyd with the
primary, secondary, and tertiary aromatic monamines.
According to this Invention the production of the said paranitro compounds is
effected as follows:-
1. The neutral nitrate of the leukobases or of the bases of the corresponding
coloring matters is added to concentrate sulphuric acid; or
2. The leukobases or the bases of the corresponding coloring matters, or a
salt of the latter, are dissolved in sulphuric acid, and a molecule of nitric acid in
the form of the nitrate of a metal or of nitric acid-ether is added by degrees; or
3. The quantity of ordinary nitric acid determined for one molecule is diluted
with sulphuric acid, and this mixture is caused to flow gradually into a solution of
the leukobases, or of the bases of the corresponding coloring matters in sulphuric
acid.

page_text: 2. One hundred parts by weight of tetramethyldiamidotriphenylsmethan, or one
hundred parts by weight of tetramethyldiamidotriphenylcarbinole are dissolved in
500 parts by weight of sulphuric acid, and into the solution when well cooled 26
parts of dry finely powdered nitrate of soda are introduced slowly, or 24 parts of
methyl nitrate are allowed slowly into the solution in a vessel provided with a
stirrer and a cooling apparatus with water circulation.
3. Ten parts of tetramethyldiamidotriphenylmethan or ten parts of tetramethyl-
diamidotriphenylcarbinole are heated with 50 parts of sulphuric acid. of about 63°
Beaumé until solution is effected, which takes place at about 90° centrigrade, and
the solution is then cooled again. At the same time a well cooled mixture of three
parts of nitric acid of 65 per cent. with ten parts of common sulphuric acid is
prepared, and is caused to flow in a thin stream and with continuous stirring into
the above named solution of the leukobases or of the bases of the colouring
matters.
After these operations the nitrising of the leukobases or of the bases of the
coloring matters will be completed, and the free paranitro compounds can be obtained
direct from the solutions by neutralisation of the sulphuric acid by means of an
alkali.
The paranitro compound obtained from the tetramethyldiamidotriphenylmethan,
according to the examples above given, leads by reduction and oxidation, while
that from the tetramethyldiamidotriphenylcarbinole leads only by reduction of the
nitroseries to tetramethylpararosaniline.
If one of these methods be applied to diamidotriphenylmethan or to diamido-
triphenylcarbinole, those nitro-compounds will be obtained, from which pararos-
aniline can be produced, and so on.
.ba S
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page_text: 1. One part by weight of dry neutral nitrate of tetramethyldiamidotriphenylme-
than or of dry nitrate of tetramethyldiamidotriphenylcarbinole is slowly dissolved
in five parts by weight of cooled sulphuric acid of 66° Beaumé.
2 One hundred parts by weight of tetramethyldiamidotriphenylmethan or one
hundred parts by weight of tetramethyldiamidotriphenylcarbinole are dissolved in
500 parts by weight of sulphuric acid, and into the solution, when well cooled,
26 parts of dry finely powdered nitrate of soda are introduced slowly, or 24 parts
of methyl nitrate are allowed to drop slowly into the solution in a vessel provided
with a stirrer, and a cooling apparatus with water circulation.
3. Ten parts of tetramethyldiamidotriphenylinethan or ten parts of tetramethyl-
diamidotriphenylcarbinole are heated with 50 parts of sulphuric acid of about
63° Beaumé until solution is effected, which takes place at about 90° centigrade,
and the solution is then cooled again. At the same time a well cooled mixture of
three parts of nitric acid of 65 per cent. with ten parts of common sulphuric acid is
prepared, and is caused to flow in a thin stream and with continuous stirring into
the above named solution of the leuko-bases or of the bases of the colouring
matters.
After these operations the nitrising of the leuko-bases or of the bases of the
colouring matters will be completed, and the free paranitro compounds can be
obtained direct from the solutions by neutralisation of the sulphuric acid by means
of an alkali.
The paranitro compound obtained from the tetramethyldiamidotriphenylmethan
according to the examples above given leads by reduction and oxidation, while that
from the tetramethyldiamidotriphenylcarbinole leads only by reduction of the
nitro-series to tetramethyl pararosaniline.
If one of these methods be applied to diamidotriphenylmethan or to diamidotri-
phenylcarbinole, those nitro compounds will be obtained from which pararosaniline
can be produced, and so on.
'

page_text: Having thus described the nature of the said Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondents, I
claim,―
The production of paranitro compounds from the leuko-bases generated by the
condensation of benzaldehyd with the primary, secondary, and tertiary aromatic
monamines, as also from the colouring matters produced by oxidation of the
condensation products of benzaldehyd with the primary, secondary, and tertiary
aromatic monamines.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Fifteenth day of July, in the year of our Lord One
thousand eight hundred' and eighty-one.
CHA. D. ABEL. (L.S.)